IFS2 Exam 2 Study Guide PDF

IFS2 – EXAM 2 STUDY GUIDE 1. Biomechanics of the pelvis, hip and knee a. Look at the sagittal plane and activities of the stance limb Initial Contact → Loading Response → Midstance → Terminal Stance → Pre-Swing → → Initial Swing → Mid Swing → Terminal Swing...

IFS2 – EXAM 2 STUDY GUIDE 1. Biomechanics of the pelvis, hip and knee a. Look at the sagittal plane and activities of the stance limb Initial Contact → Loading Response → Midstance → Terminal Stance → Pre-Swing → → Initial Swing → Mid Swing → Terminal Swing i. Initial contact, loading response, etc. ○ Pelvis Begins tilting anteriorly during single-limb support Slight anterior tilt just after mid stance Posterior tilt just after toe off (2nd half of stance phase) Early mid swing pelvis tilts anterior before posterior tilt in late swing ○ Hip 30 degrees hip flexion at beginning of gait cycle Extends gradually ~10 degrees hip extension At 80% of gait cycle hip flexes ○ knee At heel contact knee is flexed ~5 degrees and continues to flex to additional 10-15 degrees during loading phase Pre swing - knee reaches near full extension until heel off Swing phase - knee flexes about 35 degrees for toe clearance Stance phase - quads activated eccentrically during loading phase ii. What happens during these phases i.e. loading/unloading, ○ Loading →Stance phase (60% of gait cycle during walking) ○ Unloading → Swing phase (40% of gait cycle during walking) ○ Initial contact (heel strike) Double support Heel makes contact with the ground first. Body’s momentum counteracted by ground reaction force which decelerates body. Quads prevent excessive knee flexion as leg accepts weight. ○ Loading response Double support I Body “loads” leg and absorbs landing shock. Bodyweight shifts forward onto stance leg to begin swing. Eccentric quads to control knee flexion and prevent collapse. Eccentric glute to stabilize pelvis and prevent hip drop. Tibialis anterior contracted to control dorsiflexion. Compressive forces are increased on the knee and hip ○ Midstance Single support Bodyweight fully supported by stance leg with other leg in swing phase. Knee extended and body suspended over planted foot. Quads stabilize knee to prevent hyperextension Gluteus med & min stabilize pelvis Gastroc & soleus prepare/engage for push-off ○ Terminal stance (heel off) Single support Heel of stance leg lifts off ground and body moves forward to prepare for swing. Opposite leg begins initial contact Gastroc & soleus concentrically propel body forward to elevate heel Hip flexors activated ○ Pre swing (toe off) Double support II Stance leg pushes off ground, toe leaves ground (need toe clearance) Gastroc & soleus concentrically propel body forward Hip flexors initiate forward movement into swing phase Quads concentric ○ Initial swing Single limb advancement Begins once foot leaves ground and continues as leg moves forward Knee begins to flex and hips continue to flex Hip flexors contract to bring leg forward Quads help clear foot by lifting it off ground Dorsiflexors maintain ankle dorsiflexion to prevent dragging of foot ○ Mid swing Single limb advancement Leg moves directly under body, knee begins to extend, foot swings in prep for next step Hip flexors continue to drive leg forward Hamstrings engage to decelerate leg and control momentum Tibialis anterior maintains dorsiflexion ○ Terminal swing Single limb advancement Leg slows down before it prepares for next heel strike Knee full extends (concentric quad) in prep for next step Hamstrings eccentrically decelerate leg  Quads prepare to extend knee during next initial contact Tibialis anterior maintains dorsiflexion to ensure foot clearance and to land with heel strike first. ○ Unloading response is after stance phase when body starts to “unload” body weight from stance leg and starts to enter swing phase. This releases compressive forces at hip, knee, & ankle joints. Body weight shifts onto opposite leg. iii. How these loading/unloading assist with gait? [don’t over analyze, keep it simple] ○ Propulsion & deceleration b. Biomechanics of the knee, the patella. Osteo/arthrokinematics i. Stability of the knee = drivers of stability – muscles, ligaments, gravity, joint reaction forces ○ Knee ligaments Medial (tibial) collateral ligament (MCL) - limits valgus (ABD of tibia) Lateral (fibular) collateral ligament (LCL) - limits varus (ADD of tibia) Anterior cruciate ligament (ACL) - limits anterior translation of tibia relative to femur OR limits posterior translation of femur relative to tibia Posterior cruciate ligam ent (PCL) - limits posterior translation of tibia relative to femur OR limits anterior translation of femur relative to tibia i. Ligaments of knee are on slack in flexion and become taut in extension due to location posterior to knee joint axis ii. Rotation in transverse plane at knee is only available when knee is in flexion ○ Joint reaction forces Compressive forces are reduced by the medial and lateral menisci Arthrokinematics of knee occur due to tension in the cruciate ligaments. Screwhome mechanism or “locking mechanism” i. Allows us in typical standing position to maintain knee extension with minimum amount of knee extensor muscle activation ii. Factors: shape of medial femoral condyle, tension in ACL, lateral pull of quads and slight ER of tibia iii. Lateral rotation required for max congruency Shape of femur is curved so distal portion is posterior to proximal portion → allows line of gravity to full extend knee in normal posture  ii.Role of the meniscus, shape tibial plateau ○ Role of meniscus reduce localized pressure/compressive stress on articular surfaces by improving congruency. Increases concavity of tibial condyle → joint stability Proprioception Reduce friction Weight distribution ○ Shape of tibial plateau Medial tibial plateau is “C” shaped and larger to accommodate “C” shaped, larger medial meniscus Lateral tibial plateau is smaller to accommodate “O” shaped lateral meniscus c. Biomechanics of the hip i. Arthrokinematics/osteokinematics ○ Moves in all 3 planes OPEN CHAIN (convex femur moves on concave acetabulum) i. Abduction = superior roll, inferior glide of femur on the acetabulum ii. Adduction = inferior roll, superior glide of femur on the acetabulum iii. Internal rotation = Anterior roll, Posterior glide of femur on acetabulum iv. External rotation = Posterior roll, Anterior glide of femur on acetabulum v. Flexion = posterior spin of head of femur on acetabulum vi. Extension = anterior spin of head of femur on acetabulum CLOSED CHAIN (femur fixed; concave acetabulum moves on convex femur) i. Abduction = lateral roll and glide of acetabulum on femur ii. Adduction = medial roll and glide of acetabulum on femur iii. Internal rotation = Anterior roll and glide of acetabulum on Femur iv. External rotation = Posterior roll and glide of acetabulum on Femur v. Flexion= anterior spin of acetabulum on head of femur vi. Extension= posterior spin of acetabulum on head of femur  ii. Lumbopelvic rhythm ○ When a person is bent forward and rises or moves into extension the pelvis posterior tilts first and rotates over head of the femur then the spine extends. The glutes and hamstrings pull the pelvis backwards (posteriorly). ○ Ipsidirectional (i.e. bending to pick up something) - Pelvis & lumbar spine move SAME direction - Results in maximal angular displacement of entire trunk ○ Contradirectional (i.e. Walking / nutation+counternutation) - Pelvis & lumbar spine move in OPPOSITE directions - Results in trunk remaining relatively stable while pelvis anteriorly rotates over the femur and lumbar spine maintains lordosis iii. Trendelenburg sign, reasons? Musculature involved, mechanics ○ Trendelenburg Sign = contralateral pelvis drops damage to superior gluteal N causing weak “paralyzed/insufficient” gluteus medius and minimus 2. The SI joint function, importance, ligamentous support a. Function i. Transmits body weight from the spine to the lower extremities ii. Not a huge amount of motion here (very small magnitude of movement available) ○ Increases pre- and post-partum iii. Nutation = anterior sacral-on-iliac rotation, posterior iliac-on-sacral rotation, simultaneously iv. Counternutation = posterior sacral-on-iliac rotation, anterior iliac-on-sacral rotation, simultaneously b. Ligamentous support i. the strongest ligament in the body and prevents anterior and inferior movement of the sacrum. ii. Anterior sacro-iliac ligament iii. Posterior sacro-iliac ligament iv. Interosseous sacro-iliac ligament v. Sacrospinous ligament vi. Sacrotuberous ligament 3. Couple forces at the pelvis during gait/pelvic anterior/posterior tilts, etc. a. Anterior tilt - hip flexors & erector spinae b. Posterior tilt - hip extensors & Rectus abdominis and External obliques c. Hip hike - contralateral glute medius (stabilize) and ipsilateral QL (hike) 4. CNS connections a. The Homunculus (knee, leg, & foot are medial portion of homunculus) b. DCML (Dorsal Column Medial Lemniscus) i. Sensation to ankle/foot ii. fine touch, vibration, two-point discrimination, and proprioception c. ALS (Anterior Lateral Spinal Tract) (Spinothalamic Tract) i. Sensation to ankle/foot ii. Crude touch, Pain, Temperature d. Basal Ganglia i. Stop, Go, No-Go pathway e. Cerebellar Influence (Cerebrocerebellum) i. Role in smoothness, coordination, and timing of lower leg and ankle movements 5. Innervation LEs musculature a. Gluteal Region - Gluteus Maximus = Inferior Gluteal n. (L5, S1, S2) - Gluteus Medius = Superior Gluteal n. (L5, S1) - Gluteus Minimus = Superior Gluteal n. (L5, S1) - Tensor Fasciae Latae = Superior Gluteal n. (L5, S1) ( ↓ External Rotators ↓ provide stability “congruency” of Femoral Head) - Piriformis = Anterior Rami of S1, S2 (internal rotation also after hip flex of 60 degrees) - Superior Gemellus = N. to Obturator internus (L5, S1) - Obturator Internus = N. to obturator internus (L5, S1) - Inferior Gemellus = N. to quadratus femoris (L5, S1) - Quadratus Femoris = N. to quadratus femoris (L5, S1) b. Anterior Thigh - Pectineus = Femoral n. (L2, L3) - Psoas Major = Anterior Rami of L1, L2, L3 - Psoas Minor = Anterior Rami of L1, L2 - Iliacus = Femoral n. (L2, L3) - Sartorius = Femoral n. (L2, L3) - Rectus Femoris = Femoral n. (L2, L3, L4) - Vastus Lateralis = Femoral n. (L2, L3, L4) - Vastus Medialis = Femoral n. (L2, L3, L4) - Vastus Intermedius = Femoral n. (L2, L3, L4) c. Posterior Thigh - Semitendinosus = Tibial Division of the Sciatic n. (L5, S1, S2) - Semimembranosus = Tibial Division of the Sciatic n. (L5, S1, S2) - Biceps Femoris - Long Head = Tibial Division of the Sciatic n. (L5, S1, S2) - Short Head = Common Fibular Division of the Sciatic n. (L5, S1, S2)  d. Medial Thigh i. Adductor Longus = Obturator n. (L2, L3, L4) ii. Adductor Brevis = Obturator n. (L2, L3, L4) iii. Adductor Magnus ○ Adductor Part = Obturator n. (L2, L3, L4) ○ Hamstring Part = Tibial Division of the Sciatic n. ( L4 ) iv. Gracilis = Obturator n. (L2, L3) v. Obturator Externus = Obturator n. ( L3, L4) e. Anterior Lower Leg i. Tibialis anterior = Deep Fibular n. (L4, L5) ii. Extensor digitorum longus = Deep Fibular n. (L4, L5) iii. Extensor hallucis longus = Deep Fibular n. (L4, L5) iv. Fibularis Tertius = Deep Fibular n. (L4, L5) f. Posterior Lower Leg i. Gastrocnemius *superficial layer* = Tibial n. (S1, S2) ii. Soleus *superficial layer* = Tibial n. (S1, S2) iii. Plantaris *superficial layer* = Tibial n. (S1, S2) iv. Popliteus *Deep Layer* = Tibial n. (L4, L5, S1) v. Flexor Hallucis Longus*Deep Layer* = Tibial n. (S2, S3) vi. Flexor Digitorum Longus*Deep Layer* = Tibial n. (S2, S3) vii. Tibialis Posterior*Deep Layer* = Tibial n. (L4, L5) g. Lateral Lower Leg i. Fibularis Longus = Superficial Fibular n. (L5, S1, S2) ii. Fibularis Brevis = Superficial Fibular n. (L5, S1, S2) 6. Role of hip flexors/extensors/IR/ER a. Hip extensors *during gait* i. Concentric in early stance (hip extension) for propulsion ii. Slight eccentric activation at terminal swing for deceleration b. Hip flexors *during gait* i. Eccentric control of hip extension, after midstance ii. Concentric to flex hip at toe off iii. Concentric during first half of swing c. Hip IR - contralateral forward motion d. Hip ER - contralateral backward motion i. *movement of hip IR/ER are result of forward momentum of upper body 7. Blood supply to the hip joint and thigh a. Blood Supply to the Hip Joint - Medial and Lateral Femoral Circumflex Arteries (from profunda femoral artery) - Obturator Artery b. Blood Supply to the Thigh i. Femoral a. (Anterior Compartment) ○ Profunda Femoris a. (Adductors) Perforating a. (Hamstings and ADDuctors) ii. Obturator a. (Muscles of Medial Compartment) iii. Superior Gluteal a. (Piriformis, Glutes, TFL) iv. Inferior Gluteal a. (Pelvic Diaphragm, Piriformis, Quadratus Femoris, Glute Max, Uppermost Hamstrings, Sciatic n.) 8. Ligamentous support of the hip joint – role of these structures a. Iliofemoral Ligament = Limit Hyperextension b. Pubofemoral Ligament = Limit Hyperextension and ABDuction c. Ischiofemoral Ligament = Limit Hyperextension, ADDuction, and Flexion 9. Dermatomes/myotomes of the LEs a. Myotomes i. Hip ○ Lateral external rotation = L5, L1 ○ Medial internal rotation = L1, L2, L3 ○ Adduction = L1, L2, L3, L4 ○ Abduction = L5, S1 ○ Extension = L4, L5 ○ Flexion = L2, L3 ii. Knee ○ Flexion = L5, S1 ○ Extension = L3, L4 iii. Ankle ○ Dorsiflexion = L4, L5 ○ Plantarflexion = S1, S2 ○ Inversion = L4, L5 ○ Eversion = L5, SI iv. Toes ○ Dorsiflexion = L5, S1 ○ Plantarflexion = S1, S2  b. Dermatomes i. L1 = Upper groin and the area just below the inguinal ligament. ii. L2 = Mid-thigh region, traveling from the lateral hip toward the medial thigh iii. L3 = Lower anterior thigh, running medially toward the inner side of the knee. iv. L4 = Medial side of the lower leg, including the medial malleolus and part of the big toe. v. L5 = Anterolateral aspect of the lower leg, dorsum (top) of the foot, and most toes except for the little toe. vi. S1 = Lateral side of the foot, including the little toe and the posterior calf. vii. S2 = Posterior aspect of the thigh and calf, extending down toward the Achilles tendon. viii. S3 = Gluteal region and medial parts of the thigh. ix. S4 and S5 = Perineal region around the anus and genitals. 10. Important landmarks at the knee include areas of attachment, intercondylar eminence, pes anserinus, tibial tuberosity, tibial plateau a. Pes anserinus - tendons of sartorius m., gracilis m., and semitendinosus m. b. Tibial tuberosity - patellar ligament attachment c. Tibial plateau - medial and lateral menisci d. Intercondylar eminence - attachment sites for ACL and PCL e. Adductor Tubercle - Attachment for the hamstring part of Adductor Magnus f. Ischial tuberosity - proximal attachment site for hamstrings g. Inferior Pubic Ramus - proximal attachment site for Adductors h. ASIS - proximal sartorius attachment i. AIIS - proximal rectus femoris attachment 11. Ligaments of the Knee and their Functions a. MCL (Medial/Tibial Collateral Ligament) i. Limits Knee Valgus (ABDuction) b. LCL (Lateral/Fibular Collateral Ligament) i. Limits Knee Varus (ADDuction) c. ACL (Anterior Cruciate Ligament) i. Limits Anterior translation of the Tibia relative to the Femur ii. Limits Posterior translation of the Femur relative to the Tibia iii. DOES NOT LIMIT EXTENSION * Protects knee during Extension * iv. Taxed in Extension because Tibia is being pulled anteriorly by Quads d. PCL (Posterior Cruciate Ligament) i. Limits Anterior translation of the Femur relative to the Tibia ii. Limits Posterior translation of the Tibia relative to the Femur iii. DOES NOT LIMIT FLEXION * Protects knee during Flexion * iv. Taxed in Flexion because Tibia is being pulled posteriorly by Hamstrings 12. Planes and axis of movement a. Pelvis i. Sagittal Plane ○ Axis: Medial-Lateral ii. Frontal (Coronal) Plane ○ Axis: Anterior-Posterior iii. Transverse Plane ○ Axis: Longitudinal / Superior-Inferior b. Knee i. Sagittal Plane ○ Axis: Medial-Lateral (Frontal / Coronal) ii. Transverse Plane ○ Axis: Longitudinal / Superior-Inferior 13. Pelvic floor a. Pelvic musculature, role of these muscles, walls, innervation i. Pelvic Floor ○ Coccygeus = Branches of S4 and S5 spinal nerves Support pelvic viscera ○ Levator Ani = N. to Levator Ani (branches of S4), Inferior Anal n., Coccygeal Plexus Iliococcygeus Support pelvic viscera Pubococcygeus Support pelvic viscera Puborectalis Support pelvic viscera ii. Lateral Wall ○ Obturator Internus = N. to Obturator Internus (L5, S1, S2) Rotate thigh laterally Assist in holding head of Femur in Acetabulum iii. Postero-Superior Wall ○ Piriformis = Anterior Rami of S1 and S2 Rotate thigh laterally ABDuct thigh Assist in holding head of Femur in Acetabulum Medial rotation of thigh after hip flexed past 60° 14. Vasculature to the pelvic floor (recognize where it comes from) a. Internal Iliac a. i. Origin: Common Iliac a. ii. Distribution: Main blood supply to pelvic organs, gluteal muscles, and perineum b. Anterior Division of Internal Iliac a. i. Origin: Internal Iliac a. ii. Distribution: Pelvic Viscera, muscles of superior medial thigh, and perineum c. Posterior Division of Internal Iliac a. i. Origin: Internal Iliac a. ii. Distribution: Pelvic wall and gluteal region d. Internal Pudendal a. i. Origin: Anterior Division of Internal Iliac a. ii. Distribution: Main artery of perineum, including muscles and skin of anal and urogenital triangles, erectile bodies e. Inferior Gluteal a. i. Origin: Anterior Division of Internal Iliac a. ii. Distribution: Pelvic Diaphragm, Piriformis, Quadratus Femoris, Superiormost Hamstrings, Gluteus Maximus, and Sciatic n. f. Superior Gluteal a. i. Origin: Posterior Division of Internal Iliac a. ii. Distribution: Piriformis, all three glute muscles, and tensor fasciae latae 15. Pelvic girdle a. Function: supports abdomen, links vertebral column to lower limbs and transmits forces from lower limbs to vertebral column through trabecular systems 16. Importance of bony landmarks at the pelvis and knees (what’s attached to? What could be injured?) a. Bony landmarks at the pelvis and knees are attachment points for muscles, ligaments, and tendons. They also have clinical significance because injuries to these landmarks can result in functional impairment or pain. b. Pelvis i. Iliac Crest ○ External oblique, internal oblique, transversus abdominis, tensor fasciae latae (TFL) ii. Anterior Superior Iliac Spine ○ Sartorius, Inguinal ligament iii. Anterior Inferior Iliac Spine ○ Rectus femoris iv. Ischial Tuberosity ○ biceps femoris long head, semitendinosus, semimembranosus, Sacrotuberous ligament. v. Inferior/Superior Pubic Rami ○ Adductor Longus, Adductor Brevis, Adductor Magnus, Gracilis  c. Knee i. Patella ○ Quadriceps tendon (superiorly), Patellar ligament (inferiorly). ii. Tibial Tuberosity ○ Patellar Ligament iii. Medial Epicondyle of Femur ○ Adductor Magnus, medial collateral ligament (MCL) iv. Lateral Epicondyle of Femur ○ Lateral collateral ligament (LCL), plantaris muscle. v. Medial Condyle of the Tibia ○ Medial meniscus, semimembranosus. vi. Lateral Condyle of the Tibia ○ Lateral meniscus, iliotibial band (via Gerdy’s tubercle) vii. Fibular Head ○ Biceps femoris, Lateral collateral ligament (LCL), Common peroneal nerve runs near this area. 17. Pregnancy and its effects on the human body a. Increased cardiac output - heart pumps more blood per minute to meet elevated metabolic demands of mother & fetus b. Increased pulmonary blood flow - lungs process more oxygen to accommodate increased metabolic rate c. Changes in breast tissue - mammary glands enlarge and prepare for milk production under influence of hormones like estrogen and progesterone. d. Abdominal wall distends e. During pushing phases of labor abdominals and pelvic floor muscles contract to increase intra-abdominal pressure f. Displacement of center of mass - enlarging uterus pushes woman center of mass forward g. Increased lumbar lordosis due to anterior tilt from distended abdominals h. Changes in gait (waddle) i. Changes in muscular performance j. Hormones can increase ligament laxity, potentially affecting muscle performance and joint stability k. Pelvic floor acts as supportive sling for baby’s head l. Muscles undergo extreme stretch to facilitate passage of baby through birth canal m. Dilation stage - longest; expulsion stage - 30-60 min; placental stage - 5-60 min