Foot and Ankle Anatomy PDF

Foot and Ankle OTHN 334 Human Movement, Behavior, and Occupation & Lab Module  Ankle & Foot Bones Ankle Bones: Tibia Fibula Talus Foot Bones: Tarsals: Metatarsals Phalanges  The Foot: Bones Tarsals (7) Talus Calcaneus (heel): largest tars...

Foot and Ankle OTHN 334 Human Movement, Behavior, and Occupation & Lab Module  Ankle & Foot Bones Ankle Bones: Tibia Fibula Talus Foot Bones: Tarsals: Metatarsals Phalanges  The Foot: Bones Tarsals (7) Talus Calcaneus (heel): largest tarsal, sustains considerable force – impact & tensile Navicular: concave posterior surface, congruent with head of talus Cuboid: 6-sided 3 Cuneiform: help form foot’s transverse arch Digits 5 metatarsals 14 phalanges (2 great toe, 3 other  Ankle & Foot joints Ankle joint Where the foot is joined to leg Tibia & fibula join with Talus Foot joints A complex unit of articulations, commonly divided into three parts Forefoot Midfoot Hindfoot Provide and allow for mobility and stability  Ankle Joint Articulation between talus and distal tibia and fibula Talocrural or Talotibial joint Hinge joint One degree of freedom Plantar flexion and dorsiflexion Single oblique axis through joint Intersects with all 3 cardinal planes Cardinal planes used to describe motions  Foot Joints Multiple Joints Subtalar joint Transverse Tarsal joint (Medotarsal joint) Intertarsal joints (several between tarsals) Tarsometatarsal joint (Lisfranc’s joint) Intermetatarsal joints Metatarsalphalangeal joint Interphalangeal joints Other Multiple joints functional advantage Accommodate the foot to the terrain or in response to lower leg rotation Contribute to hollowing and flattening of foot Allows weight bearing foot to shift over toes during walking Aide in stability and balance  Ankle & Foot Motions Motions: Combined Triplanar Plantar Flexion Motions: Pronation: dorsiflexion, eversion, abduction Dorsiflexion Inversion Supination: Eversion Plantarflexion, inversion, adduction  Ankle & Foot Muscles Extrinsic Muscles: Anterior: Tibialis Anterior, Extensor Digitorum Longus (EDL), Extensor Hallucis Longus (EHL) Posterior: Gastrocnemius, Soleus, Plantaris, Flexor Digitorum Longus (FDL), Flexor Hallucis Longus (FHL), Tibialis Posterior Lateral: Peroneus Longus, Peroneus Brevis, Peroneus Tertius (Fibularis) Intrinsic Muscles Adductor hallucis, Flexor digitorum brevis, Abductor digiti minimi, Lumbricals, Flexor hallucis brevis, Adductor hallucis, Flexor digiti minimi brevis, Dorsal interossei, Extensor digitorum brevis, Extensor hallucis brevis  “Ideal” or Optimal Posture Ankle: COG is slightly anterior to ankle joint LOG anterior to ankle produces dorsiflexion Very stable; minimal muscle activity AnkleAa joint Deviations Pes planus (pronated foot) Pes cavus (supinated foot) LE Motions during gait for normal walking speed LE motions Sagittal plane: Hip: approximately 10º extension to 30º flexion Knee: 0º to 5º Ankle: 10-25º plantarflexion to 5-7º dorsiflexion Transverse plane: Hip: ER during heel strike 11 LE Motions 12 LE Motions 13 Weight Bearing Balance Postural Reactions: 1. Righting Reactions 2. Equilibrium Reactions: Return the COG to within the BOS after being perturbed Build up tone Tilt and restore Ankle Strategies Small perturbations Hip Strategies Large perturbations 3. Protective Reactions Palpation of Surface Landmarks DN pg. 245 & 247 Medial malleolus: Locate the medial aspect of the tibialis anterior, slide your fingertips distal until you palpate the large protrusion at the distal end of the tibia (A) Lateral malleolus: Locate the lateral aspect of the fibula, slide your fingertips distal until you palpate the large protrusion at the distal end of the fibula (B) Calcaneus: Locate the heel of the foot and palpate the large, round calcaneus (E)  Palpate Arches of Foot Arches serve for stability (in push off) Arches serve for mobility (adjusting to terrain) Intrinsic musculature stabilizes foot and support arches Longitudinal Arch: Metatarsal heads to calcaneal base Ligamentous support of the arches (i.e. plantar aponeurosis) Transverse Arch Transverse tarsal arch Transverse metatarsal arch Plantar aponeurosis: -Extend the big toe; palpate the tightening of the plantar aponeurosis-support of longitudinal arch -”Windlass Mechanism” important during push off AROM/PROM Ankle Dorsiflexion (DN pg. 248) Ankle Plantarflexion (DN pg. 248)  Manual Muscle Testing Ankle Dorsiflexion (DN pg. Ankle Inversion (DN pg. 262) 258-259) Gravity Resisted Position Gravity Resisted Position Gravity-Minimized Position Ankle Eversion(DN pg. 265) Gravity Resisted Position Ankle Plantarflexion (DN pg. 259-260) Gravity Resisted Position Ankle Eversion (DN pg. 265) Gravity-Minimized Position Gravity Resisted Position  Palpate Ankle Muscles Movement Prime Mover location Plantar Gastrocnemius Posterior lower leg Flexion (also Knee Flexion), Soleus Dorsiflexion Tibialis Anterior, Anterior lower leg EHL Inversion Tibialis Anterior, Anterior and Tibilais Posterior posterior lower leg Eversion Peroneus Longus, Lateral lower leg Brevis  Palpate 2-joint Muscles acting on Knee and Ankle Muscle Knee action Ankle action Gastrocnemius Flexion Plantar flexion Be careful of knee position while measuring ankle ROM!  References 2 3 Lippert, L. S., (2017). Clinical kinesiology and anatomy. (6th Ed.), FA Davis: Philadelphia, PA Oatis, C.A., (2016). Kinesiology: The Mechanics & Pathomechanics of Human Movement. (3rd ed.), Baltimore, MD; Lippincott, Williams & Wilkins Taddonio, S. (2016) Kinesiology Kardachi, J. (2017) Kinesiology Meehan, Eileen (2019) Kinesiology Randazzo, Erin (2020) Kinesiology Muscle Activity and Strength Occupation-based Functional Evaluation OTHN334 Module 2 Learning Objectives Define Occupation-based functional motion assessment Explain why it is desirable to assess motor function through observation of engagement in occupation and activity performance. Compare levels of muscle strength and associated endurance in the upper extremities. Muscle Activity Recording muscle activity Electromyography Electrodes—surface, needle, indwelling EMG is used to study the sequence of activation & relaxation Record contraction/relaxation patterns Record relative amount of specific muscle activity as they perform isolated or coordinated functions  Muscle Activation - Types of Muscle Contractions Muscle Isometric: (same length): muscle produces force with no apparent change in joint angle; no movement -e.g plank Activity Isokinetic (same speed): contraction occurs when the rate of movement is constant but the force differs -e.g. stationary bike with differing resistance levels Isotonic: (same tension) muscle produces force with a change in the joint angles, rate of movement differs but the force is constant; causes movement. -e.g. squat 2 Types of isotonic contractions: Eccentric & Concentric Muscle Activation Concentric: MUSCLE SHORTENS Muscles points of insertion move closer towards each other Causes movement acceleration, -e.g. the elbow flexors when lift glass of water to mouth. Eccentric: MUSCLE LENGTHENS Muscles points of insertion move away from each other. Causes movement deceleration, often against gravity. –e.g. the elbow flexors when lowering the glass of water from the mouth to the table This Photo by Unknown Author is licensed under CC BY-ND  Concentric motion is positive work - force exerted and produced by Positive & muscles to do the work and produce movement. Negative Eccentric motion is negative work - force exerted and produced by Work external forces to do the work and produce movement. –e.g. gravity Why we take this course…. Most clinicians do not have routine access to EMG analysis of muscle activity. Clinicians are more inclined to use their palpation skills to identify when a muscle is active or relaxed. It is best to palpate a muscle when it is lightly contracting so as to avoid contraction of surrounding muscles. Examples of Isometric exercises: Get up let’s try!! What are 5 isometric exercises? Plank Wall Sit Side plank pose (YOGA) Glute Bridge Muscle Activity— Anatomical Muscle attachments Muscles are described by: Origins-Proximal attachments Insertions-Distal attachments Actions Predicting muscle function is possible when all conditions present: 1. Proximal attachment is stabilized. 2. Distal attachment moves toward proximal (concentric contraction). 3. Distal segment moves against gravity; and 4. The muscle acts alone. Unfortunately, these circumstances rarely occur in normal function WHY? Most human activity is the result of more than one muscle. Muscle Activity—Anatomic In Summary… The body produces functional activity by the modification of these factors: (1) Proximal attachments often move toward fixed distal attachments (closed kinematic chain); (2) Contractions can be concentric, eccentric, or isometric; (3) Movement of the distal segment is often assisted by the force of gravity (4) Muscles seldom if ever act alone— they more often act with other muscles. This Photo by Unknown Author is licensed under CC Muscle Activity—Anatomic Types of Muscle Fibers I: slow twitch, resistant to fatigue -capable of repeated low level contractions IIA: fast twitch, more prone to fatigue-capable of fast, strong contractions IIB: fast twitch, rapid fatigue-capable of strong bursts of power Examples: Postural or antigravity muscles: we sit or stand for prolonged times, contain more slow-twitch or type I muscle fibers, resist fatigue (ex. Glutes, rectus abdominus, erector spinae) Rapid movement, mobility muscles or non postural muscles contain Type II muscle fibers. They produce force and power rapidly, low endurance (gastrocs, hamstrings, and UE flexors)  Agonist: (Prime Mover) contracts to produce a concentric, eccentric, or isometric contraction. Antagonist: is a muscle or a muscle group that provides the opposite anatomic action of the agonist. Synergist: muscle that contracts at the act Synergists same time as to stabilize the agonist proximal joints for distal joint movement. When synergists act in this manner, they work isometrically at joints that are not being moved by the agonists to stabilize the proximal joint, allowing the desired motion at the more distal segment to occur.  Viscosity: resistance to an external force that causes a permanent deformation. – heat decreases viscosity and makes items more moldable, cold increases viscosity and stiffens Elasticity and Extensibility: Extensibility is Muscle the ability to stretch, elongate or expand. Elasticity is the ability to succumb to an Characteristi elongating force and then return to normal when force released. cs Stress-Strain: Stress is the force the body resists. Strain is the amount of deformation body can sustain before succumbing to stress Creep: Elongation of tissue from the application of a low-level load over time can cause change  Muscle Characteristics The more extensibility a tissue has, the less viscosity it has, and vice versa. Muscle and connective tissue have both properties of viscosity and elasticity and are referred to as viscoelastic tissue. Viscoelasticity: the ability to resist changing its shape when a force is applied to it, but if the force is sufficient to cause change, the tissue is unable to return to its original shape. Muscle Strength Factors that influence muscle performance include: the muscle’s size the architecture of muscle fibers the passive components of the muscle the physiological length of the muscle or length-tension relationship of the muscle; the moment arm length of the muscle the speed of muscle contraction the active tension age and gender Muscle size Length—fibers in series Associated with “speed of motion.” Longer muscles provide mobility. Width—parallel fibers Associated with a greater ability to produce force. Shorter muscles provide stability. Two muscles with the same length- greater width is stronger than smaller diameter/width Remember: Longer muscles will provide mobility over a joint, shorter muscles provide stability. Larger surface area-greater force-generating capability e.g. the bigger the muscle the stronger it is Hypertrophy-increase with exercise Atrophy-decrease with inactivity  Muscle Strength Muscle Fiber architecture Muscle fibers: important factor determining force. More muscle fibers = more potential force exertion Strap (fusiform) Fascicles long and parallel Designed to produce greater shortening distance but less force Example: sartorius Pennate (uni-, bi-, or multi-) Attach at oblique angles to a common tendon Greater force-producing capability Most muscles in body are multi-pennate  Muscle Strength Passive/Parallel Elastic Components Fascia: Muscle is surrounded by connective tissue fascial fibers that are parallel to muscle-unable to actively change length, but follows muscle length change Endomysium: Each muscle cell or fiber is surrounded by a fascial layer Perimysium: surrounds groups of muscle fibers or fascicles Epimysium: fascial layer surrounding the entire muscl  Muscle Strength Length/Tension Relationship Resting length of muscle: a position of the muscle in which there is no tension within the muscle -the length at which the maximum number of actin-myosin cross bridges is available. As a muscle either shortens or lengthens beyond the resting position, its ability to produce force decreases because the number of crossbridge declines when the muscle fiber moves out of its resting length Active tension (muscle actively contracting) is responsible for muscle tension during shortening  Muscle Strength Active tension: Force Produced by a Muscle Active tension in a muscle is created by activation of the cross-bridges between the actin and myosin elements. Number of motor units proportional to active tension-more units more tension Type of muscle fibers (motor units) recruited influences tension The Type II muscle fibers are facilitated when a rapid or forceful response is required. Type I muscle fibers are active for postural corrections during pro-longed positioning; they frequently fire as needed to make small corrections to maintained a position in spite of either external factors  Muscle Strength Moment arm The muscle’s moment arm is: 1. The lever arm that produces rotation around a joint. 2. The length of a perpendicular line from the joint’s axis of motion to the muscle’s force vector or line of pull. Example: elbow at 90°, biceps 100% of muscle force rotates joint when insertion is insertion perpendicular to bone segment Angle of insertion influences torque  Muscle Strength Speed of Contraction Speed is a rate of motion, and velocity is rate of motion in a particular Velocity direction. Muscle shortens: Speed of a concentric contraction decreases, the muscle’s force development increases. Muscle strength decrease with speed. Muscle lengthens: Speed of an eccentric contraction increases, the rfa u s t le i ld o e n s a ts o fe f x a M tr e u n s a tc s , l e t b h s u e t js o t ii n l tl (  Open vs. Closed Kinetic Chain Open Distal segment free to move Uninfluenced by other segments or joints Non-weight-bearing Often facilitate rapid movement Close Distal segment fixed Influenced by both proximal and distal segments Weight-bearing Often facilitate strength and power  Open and closed chain occur in functional UE and LE activities and occupations UE is more often open chain LE is more close chain Open chain activities often facilitate Open vs. rapid movements Closed chain functions are used to Closed develop force and power Open chain activities: Throwing a ball Closed chain activities: Squatting  Muscles injuries are extremely common Often occur during eccentric/deceleration Exercise activities Induced Delayed Onset Muscle Soreness Decrease in ROM due to pain Muscle Recovery from 5-30 days If exercise repeated post recovery and DOMS does not occur, muscle adapted Injury Muscle Strain Sudden, sometimes severe injury Muscle tear Most often occurs to hamstring in springing and jumping activities Occupation-Based Functional Evaluation A way of assessing ROM, Strength, and motor control available for task performance by observing the client during performance of everyday occupations (ADLs, IADLs, education, work, social participation, leisure activities, and rest and sleep). Primary responsibility of the occupational therapist is to assess occupational performance, identify performance problems, and plan intervention strategies that will improve the client's ability to fully engage in occupations, sensorimotor limitations first should be assessed through observation of functional activities. Clinical Observation Functional motion assessment ( putting dishes away, stepping into a tub) Individual activity analysis: diagnose occupational problems of client Questions to ask: 1. Does the client have adequate ROM to perform tasks? Joint limitations? 2. Does the client have enough strength to perform the tasks? Which muscle groups are weak? 3. Does the client have enough motor control to perform the task? Is movement smooth and rhythmic? Slow and difficult? Extraneous movements? References: Buccina, M. (2022). Kinesiology Head, Neck, and Trunk OTHN 334 Human Movement, Behavior, and Occupation & Lab 54 The Head, Neck & Trunk Allow stability and mobility for limb motion Protect vital organs: brain, spinal cord, heart and lungs Vulnerable to injury sports and accidents degenerative conditions 55 Vertebral Column 33 vertebrae 23 intervertebral disks Divided into five regions Cervical Thoracic Lumbar Sacral Coccygeal  The Vertebral Column Curves: Anterior-posterior curves Convex Anterior Cervical Lumbar Concave Anterior Thoracic Sacral Provide more strength and resilience than a straight line of bones 56  The Vertebral Column Another way to describe: Concave posterior Cervical Lumbar Convex posterior Thoracic Pelvic Lordotic curves: anterior convexity (posterior concavity) Kyphotic curves: posterior convexity (anterior concavity) 57 Developmental Curves At Birth: Single column, convex posteriorly Kyphosis-primary curve Child: Picks up head-concave posterior cervical curve Lordosis-secondary curve Begins standing-convex anterior lumbar curve (Due to Psoas muscle pull) 10 Years old: Fully developed The Moveme Description nt 1=neck 2=trunk Vertebr Flexion 1. Chin towards sternum 2. Shoulders towards al hips Extension 1. Look towards ceiling Column 2. Lean back Lateral 1. Ear towards shoulder flexion 2. Side bend Rotation 1. Look over shoulder 2. Turn upper body towards back 59 The Vertebr Moveme Plane nt Axis al Flexion Sagittal Frontal Column Extension Sagittal Lateral Frontal Frontal Sagitta flexion l Rotation Transverse Vertical 60  Kinematics Sagittal Plane Flexion: anterior tilting and gliding of superior vertebra Extension: posterior tilting and gliding of superior vertebra Frontal Plane Lateral flexion (side bend): superior vertebra laterally tilts, rotates and translates Horizontal Plane Rotation: accompanies lateral flexion Coupling: one motion around an axis with another motion around a different axis. Lateral flexion and rotation. 61  Function of Cervical Region 62 Most flexibility Stability: atlanto-occipital & atlantoaxial joints Essential for support of head, protection of spinal cord and vertebral arteries. Motions: flexion, extension, lateral flexion and rotation Lateral Rotation bending Flexion and  Joints: Thorax and Chest Wall ◻ Intervertebral 63 ◻ Between adjacent vertebral bodies ◻ Chondrosternal/Costochondral ◻ Between ribs and sternum ◻ Costovertebral (CV) ◻ posterior ends of ribs and vertebral bodies ◻ Costotransverse (CT) ◻ posterior ends of ribs and transverse processes Motions Much less motion than cervical or lumbar and spine FLEXION/EXTENSION Muscles: Sagittal plane, frontal axis LATERAL FLEXION Thorax Frontal Plane, sagittal axis ROTATION and Transverse plan, horizontal axis ELEVATION/DEPRESSION OF RIB Chest CAGE Associated with respiration Wall 64 Rib Cage Motions 65 Rib Cage Motions Combined frontal elevation and depression = bucket- handle motion Elevation of lower ribs at CV and CT joints results in lateral motion of rib cage Type of hinged motion that mimics the up and down movement of a bucket handle 66 Rib Cage Motions Combined sagittal elevation and depression = pump- handle motion Elevation of upper ribs at CV and CT joints results in anterior and superior movement of the sternum Type of hinged motion that mimics the up and down movement of a pump handle 67  Critical motion for many tasks, including postural stability and mobility Function Greatest mobility between L4, L5 and S1 of Lumbar Area that supports most weight. Region Motions: Flexion, extension, lateral flexion and rotation 68 69 Motions Lumbar spine Side bend or lateral flexion Flexion and Extension  The Pelvis Part of the hip joint Attaches axial skeleton to inferior appendicular skeleton Base of support for rest of body Position of pelvis dictates seated posture Proper seating options and positions crucial for optimal function 70 Motion of Nutation: refers to the anterior inferior movement of the sacrum Pelvic while the coccyx moves posterior to the ilium Counternutation: refers to the Girdle posterior superior movement of the sacrum while the coccyx moves anterior to the ilium –the sacrum moves opposite the pelvis https://video.search.yahoo.com/s earch/video?fr=mcafee&ei=UTF-8 &p=nutation+vs+counternutatio n&type=E210US91088G91350#i d=1&vid=566934dbab2af2b0559 7185a573d3359&action=click 71  Motion of Pelvic Girdle Nutation (sacral flexion) Superior sacrum moves anteriorly and inferiorly Causes inferior portion/coccyx to move posteriorly Increases diameter of pelvic outlet Occurs with lumbar extension Prone press up Occurs with pelvic posterior tilt Relative motion compared to innominate Back lying, hip flexion - child birth 72  Motion of Pelvic Girdle Counternutation (sacral extension) Superior sacrum moves posteriorly and superiorly Causes tip of coccyx to move anteriorly Decreases diameter of pelvic outlet Occurs with lumbar neutral or flexion Sitting, slumping, trunk flexion Occurs with pelvic anterior tilt Relative motion compared to innominate Walking, hip extension- early stages of labor 73  The Pelvis Neutral: Equal weight distribution across femurs in sitting; erect spine Anterior tilt: Superior pelvis tilts anterior lumbar hyperextension, hip flexion. Causes center of gravity to shift forward Posterior tilt: Superior pelvis tilts posterior, tailbone tucks beneath body  lumbar curve flattened, hip extension Lateral tilt  trunk laterally flexes in opposite direction Rotation  trunk rotates in opposite direction 74 Anterior Pelvic Tilt Anterior  75  Pelvic Lateral Tilt Left lateral tilt: anterior view ASIS’s level = no lateral tilt Right lateral tilt: posterior view. Note other motions affected by lateral pelvic tilt Left lateral tilt (left side 76 lower)  Pelvic Rotation A. Neutral position B. Right forward rotation (right side forward, left side hip medial rotation) C. Right backward rotation (right side backwards, left side hip lateral rotation 77 Pelvic motions 78  The Pelvis: motions Movement Plane Axis Anterior tilt Sagittal Frontal Posterior tilt Sagittal Frontal Lateral tilt Frontal Sagittal Rotation Transverse Vertical 79  The Pelvis Movement Description Anterior tilt ASISs move anterior to pubic symphysis (tilts forward) Posterior tilt ASISs move posterior to pubis symphysis (tilts backward) Lateral tilt Iliac crests/ASISs are not level Rotation One side moves forward or back in relation to the other 80 Lumbopelvic Rhythm Relationship of lumbar flexion to anterior pelvic rotation Ability to touch toes: function of pelvis rotation, hamstring extensibility and lumbar flexion ROM Sequence: Neutral towards full flexion: L spine flexion Pelvis rotates anteriorly on hip joints: Anterior pelvic tilt Sacrum counternutation Followed by hip flexion Return from flexion Posterior pelvic tilt Sacrum nutation until S1 aligns Extension of L spine 81 “Ideal” or Optimal Posture Head and Neck: Ideally, plumb line should pass through the lobe of the ear LOG passes slightly anterior to horizontal axis of movement Head tends to tilt forward Constant pull of gravity on head into flexion counteracted by internal tension and muscle activity “Ideal” or Optimal Posture Vertebral Column: LOG passes through the body of 5th lumbar vertebra and close to the axis of lumbosacral joint Scoliosis Lateral curvature of spine in thoracic or lumbar regions Named according to location of convexity (e.g. R thoracic scoliosis) Functional: soft tissue imbalance Structural: bony changes + soft tissue abnormalities  References 85 Dapice-Wong, S. (2021). Kinesiology. Kardachi, J. (2017) Kinesiology Lippert, L. S., (2017). Clinical kinesiology and anatomy. (6th Ed.), FA Davis: Philadelphia, PA Meehan, E. (2019) Kinesiology Oatis, C.A., (2016). Kinesiology: The Mechanics & Pathomechanics of Human Movement. (3rd ed.), Baltimore, MD; Lippincott, Williams & Wilkins Randazzo, E. (2020) Kinesiology Taddonio, S. (2016) Kinesiology Overview of Lower Extremities: Motion, Occupations, Applications, Gait/Posture OTHN 334 Human Movement, Behavior, and Occupation & Lab Gait Gait is upright locomotion on foot Walking, running, jogging One of the most common functional daily movements Typically, smooth and efficient without conscious effort  Gait: Step 88 Step Step length: distance between heel strike of one foot and heel strike of the other 2 steps (one with left foot and one with right) complete one stride Gait Stance Phase (60% of cycle, closed chain): Some part of foot in contact with ground Begins with heel strike of one foot Ends when that foot leaves ground (for next step) Swing Phase (40% of cycle, open chain): When foot is not in contact with ground Slight overlap between the 2 phases 89  1. Heel Strike/Initial Contact Initial contact of heel of stepping foot to ground. Weight is also on opposite foot double limb support 2. Foot Flat/Loading Response Stepping foot is flat on ground Stance 3. Midstance Stepping limb supports body weight and Phase 4. balances, while opposite leg leaves ground single limb support Heel off/Terminal Stance Stepping foot heel leaves the ground Ball of foot and toes remain in contact Weight transfers to opposite leg 5. Toe off/Pre-swing Toes push off ground, acceleration 90  1. Initial Swing Foot is no longer in contact with the ground Swing 2. Midswing Tibia perpendicular to the ground; Phase middle part of the swing 3. Terminal Swing Leg prepares to make initial contact (stance phase); leg is coming down Gait Cycle Gait cycle = 1 stride What occurs between one foot touching the floor and the same foot touching the floor again 92 Stance Phase 93 Swing Phase 94 Gait Cycle 95 Gait Cycle LE Motions 97 LE Motions 98 Posture This Photo by Unknown Author is licensed under CC BY 99 Posture Position of head, trunk and limbs in relation to each other Alignment of body standing, sitting, or recumbent. Ideal posture minimal stress to each joint requires strong, flexible muscles  STATIC BALANCE: Posture and body segments aligned & maintain upright positions when not moving standing, sitting, lying, kneeling Posture & Prevent a shift in COG DYNAMIC BALANCE: Balance maintain upright position while body or body segments are moving reaching, walking, running, jumping, throwing, lifting Shift COG within BOS Lordosis and Kyphosis Lordosis: normal Kyphosis: normal sagittal plane sagittal plane anterior convex posterior concave curves in cervical curves in the and lumbar thoracic and pelvic regions regions  Goal is the same as standing: Stable alignment of body that uses least amount of energy and least Sitting stress on structures More complex than standing Posture Contact forces in addition to gravitational forces LOG passes close to joint axes of head and spine, in erect sitting posture Optimal Sitting Posture Non-Optimal Sitting Posture Flexion relaxation phenomenon Slumped sitting posture less muscle activity than erect posture Passive tissues assume the load in slumped sitting Increases pressure on disks Posture & Writing in Children Upright posture is foundational for fine motor skills (hold writing utensil) Line of vision (view the board) Tracking visual information (reading, writing) Attention Body Mechani cs Body Mechanics: Adjust Posture Stabilize Wide, stable BOS Foot position tighten abdominal muscles Align and maintain curves of back Position in relation to task Plan your movements Direction of open stance Position feet according to the -direction of movement one foot ahead of the other and in a sideways direction Square pelvis to task Body Mechanics to prevent injury DO NOT DO bend, flex, rotate, twist trunk Position feet and LE to bend, move Lumbar spine is frequently affected during improper lifting; LBP or lift reach away from body Golfer’s lift Lowering your COG increases your use small joints and muscles stability to lift Bend the knees! ie : vertebrae of your back Keep load close Use Strongest body parts to lift or move whole body Legs  References Dapice-Wong, S. (2022). Kinesiology Kardachi, J. (2017) Kinesiology Lippert, L. S., (2017). Clinical kinesiology and anatomy. (6th Ed.), FA Davis: Philadelphia, PA Meehan, E. (2019) Kinesiology Oatis, C.A., (2016). Kinesiology: The Mechanics & Pathomechanics of Human Movement. (3rd ed.), Baltimore, MD; Lippincott, Williams & Wilkins Randazzo, E. (2020) Kinesiology Taddonio, S. (2016) Kinesiology 111  Application of Kinesiology Concepts Joint Structure, Function, & Occupation OTHN 334 Human Movement, Behavior, and Occupation & Lab Occupational Therapy Framework-4 (AOTA, 2020) Analysis of Occupations Occupations are central to a client’s health, identity, and sense of competence and have particular meaning and value to that client. Occupations include things people need to, want to and are expected to do” (WFOT, 2012a, para. 2). Client Factors (AOTA, 2020) Body Functions & Body Structures Neuromusculoskeletal and movement related Nervous system Muscular system Skeletal system Bones This Photo by Unknown Author is licensed under CC BY-SA-NC Joints Kinesiology Analysis of human movement in our occupations How does a person walk? Throw? Reach? What muscles are being used? How much motion is required at each of the joints to execute efficient and effective movements? Applies the appreciation of the beauty of human movement with understanding of scientific principles that provide movement. Kinesiology The Study of Movement Related to Living Things Relationship between complex structures of the body A&P = structures and how they work Kinesiology = how components work together to cause movement Kinematics: Motion of bodies in space Osteokinematics: Movement of bones Arthrokinematics: Movement of joint surfaces Kinetics: Push/pull (force) on a body or body part resulting in motion  Clinical kinesiology: Biomechanics Application of kinesiology to environments Understand movement and the forces acting & Clinical on the human body Kinesiology Learn to manipulate forces to prevent injury, restore function, and provide optimal human performance Why study kinesiology? Must understand relationships between bones, joints, tendons, nerves, muscles, and how they cause movement Must use correct terminology for accuracy Understanding Kinesiology Understanding evaluation and treatment: What is going on: with and for the patient? For best practice, need to link kinesiology concepts to client treatment and OT theory Need to understand NORMAL movement to understand pathology & deviation from the “norm” when something is not right Anatomical Position Reference position of the body in a static, or nonmoving position. Standing position with feet, knees, body and head facing forward, and shoulders rotated so palms of the hands face forward, and fingers extended Midline Imaginary line drawn down the center of the body From cranium to floor Divides the body into RIGHT & LEFT halves Used as reference point for location of all structures and direction of movements Directional Positions When lying down: Prone = face down, lying on belly Supine = face up, lying on back Directional Positions Near/Away from Midline: Medial = towards the midline (hint: think “middle”) Lateral = away from the midline or toward the side Proximal = closer to midline or another structure (closer to trunk) Distal = further from midline or another structure (think “distance=further away”) Directional Positions Front/Back: Anterior = towards the front of the body Posterior = Towards the back of the body Ventral = towards the front Dorsal = towards the back Describes structures in foot, ankle, spinal cord, and sometimes hand/forearm Directional Positions Towards/Away from the surface: Superficial = towards the surface Deep = away from the surface Directional Positions Towards Top/Bottom (6 terms): Superior = towards head/above another structure Inferior = towards feet/below another structure Cranial = towards the skull (cranium) Caudal = below, towards the “tail” Supra = above a structure Infra = below a structure  Anterolateral: front and away from midline Combined Anteromedial: front and near to midline Posterolateral: back and away from midline References Posteromedial: back and near to midline Take a think break!! https://youtu.be/pQUMJ6G h9Bw  Flexion: Bending movement where one bone segment moves towards the other and a decrease in the angle of joint Extension : Naming Movement of one bone segment away from the other bone producing a greater joint angle Hyperextension: Movements If extension goes beyond the anatomical reference position. at Joints Abduction: Motion away from midline (must have memorized by next week!!) Adduction: Motion towards midline Lateral flexion: Occurs at trunk  Rotation: Movement of bony segment around a vertical axis Medial (Internal) or lateral (external) Pronation: Naming Palm down position of forearm Movements Supination: at Joints Palm-up position of forearm Inversion/Eversion: (must have memorized by next week!!) Rotation at the foot Retraction/Protraction: Scapular movements Planes of Motion and Axes of Motion All movements occur in a plane and around an axis. 3 anatomical planes of movement: “surfaces” along which movement occurs Each plane is perpendicular (90° angle) to the others This Photo by Unknown Author is licensed under CC BY-SA Anatomical Planes Sagittal (median): Vertical plane from head to toe Divides body into right and left halves Frontal (lateral or coronal): Vertical plane from head to toe Divides body into anterior & posterior halves Transverse (horizontal): Horizontal plane through body Divides body into superior & inferior sections Axes Movement occurs around a joint at the axis Fulcrum, or center of the arc of movement “Line” or Location around which the movement occurs Each axis is perpendicular (90° angle) to each plane and each pair is in partnership Sagittal Plane Sagittal Plane: (Anterior/posterior plane ) Parallel to sagittal suture of the skull Side view and joint motions are Flexion/ Extension Parts come together is Flexion; Parts move away is extension Motion beyond anatomical position is hyperextension Coronal/Frontal Plane: Parallel to the frontal bone along the coronal skull suture Motion away from midline Abd/adduction (hip, shoulders, digits) Ulnar and radial deviation Lateral flexion or bending (neck/Trunk) Elevation/Depression (Scapula) Horizontal Plane or Transverse plane: Divides body into upper and lower parts Motions that occur: Internal and External Rotation (hip& shoulder) Pronation / Supination (forearm)  Quiz time: What’s the plane of movement? What’s the axis? This Photo by Unknown Author is licensed under CC BY-NC-ND Sagittal Plane Frontal Plane ABDuction ADDuction Elevation Depression Frontal Plane Lateral Bending Ulnar and Radial Deviation Transverse Plane Internal and External Rotation Horizontal ABDuction and ADDuction Transverse Plane Protraction Retraction Pronation Supination Osteokinematics Arthrokinematics (Physics of movement) Chains Forces Levers Joints and Arthrokinematics Joint: Connection between bones (usually 2 bones) Several functions: Allow motion: Bear weight; provide stability; absorb forces Types: Synarthrodial Immovable such as suture joints in skull Amphiarthrodial Limited movement, cartilaginous, pubic symphysis Diarthrodial/Synovial Freely moveable, but not as stable Majority of joints in the body are of this type This Photo by Unknown Author is licensed under CC BY-SA-NC Diarthrodial/Synovial Joints The number of planes within which a joint moves Indirectly connected to one another by means of a joint capsule that encloses the joint Three main categories: UNIAXIAL BIAXIAL TRIAXIAL Synovial Joints Amount of movement determined by degrees of freedom One degree of freedom (uniaxial),AKA hinge/pivot Moves in one plane around one axis Two degrees of freedom (biaxial); AKA condyloid and saddle Can move in 2 planes around 2 axes Three degrees of freedom (triaxial); AKA ball and socket Can move in 3 planes around 3 axes Circumduction: Motion in which moving segment follows a circular path. Occurs in triaxial Uniaxial Hinge Joint Pivot (trochoid) joint Biaxial: Condyloid joint: One bony Saddle joint: Each bony component component is concave and the other is both convex and concave convex CMC joint of the thumb MCP hand Triaxial Plane Joint: Ball and Socket Joint: each surface may glide or rotate with each surface may glide or roll and the other. rotate with the other E.g. carpal joints E.g. - HIP joint, Shoulder/GH joint Arthrokinematics Arthro = joint; Kine = movement Arthrokinematics = what happens within the joint when movement occurs Joint surface shape influences movement: Ovoid – convex-concave Joint surface: one bone convex, the other concave Most synovial joints Sellar – saddle shaped Each joint surface = convex one direction, concave other Extent of convexity/concavity varies Arthrokinematics Ovoid: Convex-concave Sellar: Saddle shaped Arthrokinematics 3 types of movement: Roll: One joint surface on the other, new points on each surface coming into contact throughout movement E.g. ball rolling on the ground Glide (slide): Linear movement of joint surface A parallel to joint surface B, one point of joint surface A coming into contact with new points on B Box sliding down a ramp, tires skidding Spin: Rotation of a moveable joint surface on a fixed adjacent joint surface: same point on each surface in contact Top spinning on table Arthrokinematics LETS TRY IT: Make a fist with your L hand (convex) Place inside cupped right hand (concave) What direction does your joint surface move when you: Raise your L elbow? Raise your R elbow?  Arthrokinematics Closed-pack position: Maximum contact of jt. surfaces Most stable position, ligament attachments are furthest apart, capsular structures are taut Joint mechanically compressed and hard to pull apart Injury less likely to occur Open-pack position: Minimal contact of jt. surfaces Less stable, less total contact of joint surfaces, supporting ligaments are slack, joint pliable Resting position – relaxed (AKA loose packed) Kinematic Chains Kinematic Chain Series of rigid links (bone) connected (by tendons, ligaments, cartilage, muscles) to allow movement Movement at one link in chain causes movement at other links in predictable ways May be open, closed or combination Open Chain: Distal elements are able to freely move Self-feeding Closed Chain: Distal elements are restricted from movement Push-up Combination Open/Closed Walking  Open packed aka “loose packed position” Proximal segment is fixed, distal segment Open moves freely Distal segment is free to move in many Kinematic directions One joint can move in isolation, without Chains impacting other joints Used for many functional activities Waving, chopping, writing, feeding self or others Closed Kinematic Chains Distal segment is fixed/restricted from movement, proximal segment moves Maximum area of surface contact occurs Capsular structures are taut Limb segments move in limited and predictable directions Movement at one joint necessitates movement at other joints in the chain Used for stability, esp. w/poor balance Squats, push up Combination Open/Closed = walking  This Photo by Unknown Author is licensed under CC BY Quiz time: Open or closed chain? Forces and Laws of Motion Kinetics: Study of forces acting on the body Force: a push or pull on a body which results in movement or displacement All Forces are vectors This Photo by Unknown Author is licensed under CC BY-SA-NC - Magnitude (pound or newton) - Direction (# of degrees with respect to a known reference) This Photo by Unknown Author is licensed under CC BY-NC Forces acting on Human Body Force = Push ( → compression) or Pull (→ tension) on a body which results in movement Movement occurs if one opposing force pushes/pulls harder OR when 2 or more forces work together All Forces are vectors, describing Magnitude Direction Internal: Muscles, ligaments, bone… External (can be primary or secondary): gravity, friction, atmospheric pressure, weights, acceleration… (more to come) This Photo by Unknown Author is licensed under CC BY Torque (Moment of Force) Ability of force to produce rotation around an axis Torque is a rotary force Amount of torque depends on: Amount of force (muscle strength) Length of lever (distance between the attachment of the muscle and the center of rotation of the joint) This Photo by Unknown Author is licensed under CC BY-SA Can increase torque by increasing force or increasing length of lever Think of using a wrench to undo a tight nut Force Couple Two or more forces with similar magnitude Opposite or significantly different direction of force Applied to the same object at the same time Causes rotary movement Creates increased force or strength of movement Major example: upward & downward rotation of shoulder This Photo by Unknown Author is licensed under CC BY-SA Newton’s Laws of Motion 1ST LAW: LAW OF INERTIA Object at rest tends to stay at rest; object in motion tends to stay in motion (= “inertia”) A force is required to overcome inertia & cause object to move, stop, change direction Acceleration depends on force applied and object’s mass: E.g. friction will slow/stop acceleration Newton’s Laws of Motion 2ND LAW: LAW OF ACCELERATION Any change in velocity of object If forces acting on object/body are not Zero, the bodies will accelerate or decelerate Rate of acceleration is: Proportional to the force Inversely proportional to the mass E.g. same amount of force to basketball and bowling ball = bowling ball does not go as far. Newton’s Laws of Motion 3RD LAW: LAW OF ACTION/REACTION For every action, there is an equal and opposite reaction Strength of reaction is always equal to strength of action E.g.: force from floor pushing back as you jump Ground reaction force: what you feel in your legs when you jump off a small step No motion can occur without a force Force of friction Force between two objects, which resists sliding of the surfaces i.e. Shear Force Static friction Friction between non- moving bodies i.e. friction prior to sliding Dynamic friction Friction between bodies that are moving or sliding on one another. Center of Gravity Equivalent center of mass Balance point of object Torque on all sides is equal On body: Point where all planes intersect Changes with different body proportions and growth And with shift over Base of Support (BOS) (part of body in contact with support surface) Center of Gravity Center of Gravity Changes with Body Position Center of Gravity Changes with Body Size and Position  Lever = Simple machine that consists of a rigid bar that rotates around an axis, or fulcrum First Class Lever: Balance between two forces, axis in middle Levers & See-saw Second Class Lever: Designed to enhance Classes strength Wheel barrel Third Class Lever: Designed to enhance speed and range of motion Shovel First Class Lever: (See-Saw) Axis/Fulcrum in middle, between force and resistance Requires balance for optimal performance; however, fulcrum may not be in center. Not so common in human body Head on C1 Second Class Lever (Wheel Barrel) Second Class: fulcrum one end, resistance in middle, force other end Resistance closer to fulcrum than force, so less force needed. Least common in human body Ankle plantar flexors, standing on tip toe Third Class Lever: (Shovel) Third Class: fulcrum at one end, force in middle, resistance at opposite end Force closer to fulcrum than resistance, so small resistance moved by larger force Very common in body, many joints Third Class Lever: (shovel and tongs) Levers in the Human Body https://youtu.be/VQjaIvx5iRM Levers Changing component parts can make task easier to accomplish Force arm Lengthening force arm makes task easier Resistance arm Shortening resistance arm makes task easier That is: less force is required when the resistance is close to the axis/fulcrum, and the force is applied further away Consider for future practice References American Occupational Therapy Association. (2020). Occupational therapy practice framework: Domain and process (4th ed.). American Journal of Occupational Therapy, 74 (Suppl. 2) Houglum, P.A., & Bertoti, D. B., (2012). Brunnstrom’s Clinical Kinesiology (6th ed.), F.A. Davis Lippert, L. S. (2017). Clinical kinesiology and anatomy. (6th Ed.), FA Davis: Philadelphia, PA Oatis, C.A., (2016). : The Mechanics & Pathomechanics of Human Movement. (3rd ed.), Baltimore, MD; Lippincott, Williams & Wilkins Taddonio, S. (2016) Kinesiology  Pelvis and Hip OTHN 334 Human Movement, Behavior, and Occupation & Lab  Bones: Pelvic Girdle Bony Anatomy of Pelvis Sacrum Coccyx Right and Left Innominate bones 3 fused bones Ilium Ischium Pubis Acetabulum Surface ilium, ischium, pubis Pelvic Girdle Function Stability Support and transmit force Walking, running, sitting Stable base for movement Head, UE, trunk, LE Protective of visceral contents Reproductive organs Joints of Hip and Pelvis Hip Joint Pelvic girdle has 3 main joints: Right and left sacroiliac (SI) joints Tri-axial Small amount of movement Ball and socket Absorbs force, bears weight Wide range of Pubic symphysis Fibrocartilaginous disc movement Little motion Stability Absorbs force High impact movement (i.e. jump and land on feet) Lumbosacral joint Lumbar spine and sacrum connect L5 and S1 Minor joints of the pelvic girdle including: Coccygeal joints—joins the coccyx bone to the sacrum Intercoccygeal joints—connects the distal three vertebrae Copyright © 2019 Wolters Kluwer All Rig hts Reserved  Osteokinematics: Pelvis Anterior/posterior tilt sagittal plane Lateral tilt frontal plane Protraction (anterior rotation) and retraction (posterior rotation) transverse plane Copyright © 2019 Wolters Kluwer All Rights Reserved Osteokinematics: Pelvis SI joint—three degrees of freedom (small movement) Anterior/posterior rotation Adduction/abduction Medial/lateral rotation This Photo by Unknown Author is licensed under CC BY-SA Copyright © 2019 Wolters Kluwer All Rights Reserved Osteokinematics: Pelvis & Hip Region—(cont.) Osteokinematics Hip—three degrees of freedom Extension/flexion in the sagittal plane Adduction/abduction in the frontal Internal/external rotation in the transverse plane Copyright © 2019 Wolters Kluwer All Rights Reserved  Arthrokinematics of Hip Joint Movement of Joint surfaces Concave acetabulum Convex head of femur Femur moves on fixed pelvis (i.e. kick a ball) Convex head of femur moves on fixed concave acetabulum Bone roll and joint glide are in opposite directions Hip Flexion: femur bone moves anterior/superior, joint surface glides posterior/inferior Hip Extension: femur bone moves posterior, joint surface glides anterior Hip Abduction: femur bone moves superiorly, joint surface glides inferior Hip Adduction: femur bone moves inferiorly, joint surface glides superior Pelvis moves on a fixed femur (i.e. bend to pick something up from the floor) Concave acetabulum moves on a fixed convex head of femur Bone roll and joint glide are in the same directions Anterior pelvic tilt: Pelvis bones moves anterior, joint surface glides anterior Posterior pelvic tilt: Pelvis bones moves posterior, joint surface glides posterior Hip Muscles Motion Muscle group Location Plane of movement Hip Iliopsoas Anterior to hip joint Sagittal Plane Rectus femoris Flexors Sartorius Pectineus (also primary adductor) Tensor Fascia Latae (also primary abductor) Hip Gluteus maximus Posterior to hip joint Sagittal plane Hamstrings Extensor Biceps femoris s Semitendinosus Semimembranosus Adductor Magnus (posterior fibers)  Hip Muscles Motion Muscle group Location Plane of movement Hip Adductor longus Medial to hip joint Frontal Plane Adductor brevis Adducto Adductor magnus rs Gracilis Pectineus (also primary flexor) Hip Gluteus medius Lateral to hip joint Frontal plane Gluteus minimus Abducto Tensor fascia latae (also flexes and IR) rs Hip Muscles Motion Muscle group Location Plane of movement Hip Gluteus maximus Posterior and lateral Transverse Plane Piriformis Lateral/Extern Quadratus femoris to hip joint al Rotators Obturator internus Obturator externus (ER) Gemellus superior Gemellus inferior Hip Multiple contributors/no primary Transverse Plane movers Medial/Internal Gluteus medius Rotators (IR) Gluteus minimus Tensor Facia Latae Pectineus Adductor group  “Ideal” or Optimal Posture Hip: LOG falls through or slightly posterior to hip joint LOG anterior produces flexion LOG posterior produces extension In optimal posture LOG passes slightly posterior to hip joint creating slight extension Very stable, maintained by anterior ligaments & iliopsoas  “Ideal” or Optimal Posture Knee: COG is slightly anterior to knee LOG posterior to knee produces flexion LOG anterior to knee produces extension In optimal posture LOG passes anterior to knee creating extension Very stable; no muscle activity needed to stay extended  “Ideal” or Optimal Posture Ankle: COG anterior to ankle Forces tend to produce dorsiflexion; soleus isometrically prevents falling forward LOG anterior to ankle produces dorsiflexion LOG posterior to ankle produces plantarflexion In optimal posture LOG anterior to ankle creating dorsiflexion tendency Opposed by internal plantarflexion to prevent forward motion of the tibia LE Motions 195 LE Motions 196  Pelvic and COG Movement During Gait Horizontal displacement (transverse plane): Pelvis Pelvis rotates slightly anterior (4-10º protraction) On the side in swing phase as hip flexes Pelvis rotates slightly posterior (4-10º retraction) on the side in stance phase as hip extends COG moves laterally (side to side) toward stance leg 197  Other Pelvic Movement During Gait Frontal plane Pelvis Lateral tilt Slight, controlled drop (approximately 5º) when weight removed from extremity at toe off/pre-swing Opposite side (stance side) hip abductors (gluteus Medius) and same side erector spinae eccentrically control this tilt 198  COG Movement During Gait Vertical displacement (sagittal plane): COG moves up/down through gait cycle Highest at midstance, lowest at initial contact (heel strike) 199 Active & Passive Insufficiency Hip muscles that cross two or more joints Psoas, Rectus femoris, Sartorius Hamstrings (Biceps femoris, Semitendinosis, Semimembranosis) Tensor Facia latae  2-joint Muscles acting on Hip and Knee 20 1 Consider active and passive insufficiency with the 2-joint muscles of the hip and knee. Active cannot shorten (contract) further, passive cannot lengthen further Knee OTHN 334 Human Movement, Behavior, and Occupation  Bones of The Knee Bones: Femur (distal end) Tibia (proximal end) Patella (Fibula is in the region but does not articulate with the knee) Bones of the Knee: Femur Distal Femur Epicondyles--lateral and medial Condyles—lateral and medial Covered with articular cartilage Connected anteriorly, separated posteriorly medial is larger than lateral Intercondylar groove Anterosuperior aspect of condyles where posterior patella articulates with femur Intercondylar fossa Separates the two condyles at their most inferior aspects Cruciate ligaments pass through Patellar surface Bones of the Knee: Tibia and Fibula  Proximal Tibia Intercondylar eminence: double pointed prominence on proximal surface. Eminen Sits in femoral intercondylar ce fossa when knee is extended Lateral & Medial Condyles Medial larger than lateral Tibial tuberosity: large projection on anterior surface  Bones of the Knee: Patella “Knee Cap” Inverted triangular shaped bone Articulates with the femur Located within quadriceps tendon Sesamoid bone Small bone within tendon to protect the tendon and change the angle of pull Patellar ligament-continuation of quadriceps; connects patella and tibia  Improves the efficiency and increase torque of the knee extensors throughout the knee’s range of motion Centralizes the forces of the quadriceps muscles into one concerted direction of pull Functions Provides a smooth gliding mechanism for the quadriceps muscle and tendon to of Patella reduce compression and friction forces Contribute to the overall stability of the knee Provide bony protection from direct trauma to the femoral condyles when the knee is flexed.  Proximal Fibula Lateral to and smaller than tibia Not part of knee joint Does not articulate with femur Provides attachment point for ligaments & other structures  Knee Joints Tibiofemoral joint Articulation between the distal femur and proximal tibia Patellofemoral joint Articulation between posterior patella and the femur (Superior tibiofibular joint) Not considered part of the knee complex; not contained within the knee joint capsule  Knee Joint: Tibiofemoral joint Articulation between distal femur and proximal tibia Largest joint in body Double condyloid joint 2 Convex femoral condyles 2 concave tibial condyles Uniaxial synovial “hinge” joint Not true hinge: has some accessory rotation Primary motion: Flexion/Extension (sagittal plane) Accessory motions: Internal/external rotation in transverse plane  Knee Joint: Patellofemoral Joint Articulation between the patella and femur Patella = anatomical pulley Increases mechanical advantage of the quadriceps Changes the angle of pull Distribute forces Centralizes force of four quadriceps muscles into one direction of pull Protects knee which is prone to degeneration During knee flexion, patella slides distally During knee extension, patella slides proximally Joint Capsule Extensive and lax Reinforced by ligaments and muscles Cruciate Ligaments Collateral Ligaments Quadricep muscles Hamstring Muscles Adds stability to the shallow tibiofemoral joint  Ligaments: Cruciate Cruciate: contained w/in capsule Between medial/lateral condyles (intercondylar region) Provide stability in sagittal plane Anterior Cruciate (ACL) Resists anterior displacement of tibia on femur Taut on extension and >90 flexion; Prone to injury Longer Posterior Cruciate (PCL) Resists posterior displacement of tibia on femur Tight in flexion; less prone to injury  Ligaments: Collateral Collateral: Located on sides of knee Provide stability in frontal plane MEDIAL COLLATERAL (MCL) Provides medial stability Resists valgus stress Taut in extension Primary structure protecting knee in flexion LATERAL COLLATERAL (LCL) Provides lateral stability Resists varus stress Taut in extension Located outside of the joint capsule  Tibiofemoral Alignment Normal angle = slight valgus angle Deviations of greater than 5º → increase stress on femur/tibia Genu Valgum Genu Varum  Menisci Fibro cartilaginous discs thicker at periphery Attached anteriorly and posteriorly Located on medial and lateral tibial plateaus Medial: C shaped, larger, more securely attached Lateral: O shaped, smaller Function: Protect joint health Provide stability Enhance lubrication Increase surface area and better absorb shock Reduce stress to joint When removed, stress to the knee is 3x stronger  Arthrokinematics of Knee Joint Knee Tibiofemoral Joint surfaces Convex femoral condyles Slightly concave tibial plateau OPEN CHAIN MOVEMENT (ie: kick a ball) Concave tibial plateau moves on convex femoral condyles Bone roll and joint glide are in same directions Knee Flexion: Tibia bone moves posterior, joint surface glides posterior Knee Extension: Tibia bone moves anterior, joint surface glides anterior CLOSED CHAIN MOVEMENT (ie: sitting down/standing up) Convex femoral condyles moves on concave tibial plateau Bone roll and joint glide are in the opposite directions Knee Flexion: femur bone moves posterior, joint surface glides anterior Knee Extension: femur bone moves anterior, joint surface glides posterior Tibiofemoral Joint Flexion Reduced when hip is extended due to rectus femoris Some medial tibial rotation occurs with knee flexion Extension Reduced when hip is flexed due to hamstrings Terminal Rotation of the Knee-in the last 20˚ of knee extension, the tibia rotates 20˚ on fixed femur. Helps provide stability to knee when it ’locks’. Accessory motion of: Rotation More rotation when knee is flexed due to ligament laxity- cannot be done when knee is extended Lateral rotation twice as large as medial rotation Patellofemoral Joint No stable joint surface to keep in place Stabilized by active (e.g. muscle) and passive (e.g. ligament) constraints Must move with tibiofemoral joint Each joints’ mobility/injury impacts the other Pes Anserine Formed by the distal attachments of: sartorius gracilis semitendinosus Located on anterior medial surface of the tibia Important medial stabilizer for the knee  Knee Muscles Motion Muscle group Location Plane of movement Knee Hamstrings (also hip extensors): Posterior Sagittal Semimembranosus Flexion Semitendinosus Biceps Femoris Popliteus Gastrocnemius (primary plantar flexor) Knee Quadriceps : Anterior Sagittal Rectus Femoris (also a hip flexor) Extensio Vastus lateralis n Vastus medialis Vastus intermedius “Ideal” or Optimal Posture Knee: COG is slightly anterior to knee LOG posterior to knee produces flexion LOG anterior to knee produces extension In optimal posture LOG passes anterior to knee creating extension Very stable; no muscle activity needed to stay extended Transfers Transfers Movement from one Sit to Stand Transfer surface or position to another Shifts the center of gravity Many types of transfers Sit to Stand Transfers-Balance Static balance Dynamic Balance Sitting & Standing balance Sit --> Stand involves being able to control trunk and LEs along with dynamic balance. Sit --> Stand: Base of support changes from wide/stable base of support (hips, thighs, and feet) to a smaller/less stable one (feet)  Sit to Stand Transfer-Motion A) Lean forward in the chair Analysis Knees are flexed > 90°so that feet are under hips Ankles are dorsiflexed Body leans forward to place trunks’ A center of gravity (COG) over the legs (‘nose over toes’) Shoulders hyperextend and elbows are positioned posterior to trunk Hips concentrically flex to position trunk over thighs Iliopsoas, Rectus femoris Forearms are either pronated or in neutral Wrists are extended and thumbs/digits are flexed  Sit --> Stand B) Lift off of chair As approaching a standing position shoulders are only minimally hyperextended/neutral Elbows are extended and wrists move toward neutral Hips and knees concentrically extend Hip extension-Hamstrings and gluteus max Knee extension-Quadriceps Shift COG so head is positioning itself in alignment with feet (‘nose over toes’) C) Fully Stand Ankles move concentrically from dorsiflexion to neutral As the body moves more into a standing position and LEs support weight of the body the hands relax their grip and assume a resting position  References 22 9 Buccina, M. (2022) Kinesiology Dadio, G., Nolan, J. (2019). Clinical Pathways. Wolters Kluwer. Houglum, P., Bertoti, D. (2012). Clinical Kinesiology (6th Ed). FA Davis. Kardachi, J. (2017) Kinesiology Lippert, L. S. (2017). Clinical Kinesiology and Anatomy (6th Ed.). FA Davis. Meehan, E (2020) Kinesiology Oatis, C.A. (2016) Kinesiology: The Mechanics & Pathomechanics of Human Movement (3rd ed.). Lippincott, Williams & Wilkins. Randazzo, E. (2020) Kinesiology Taddonio, S. (2016) Kinesiology