Prosthetic Lec 3 PDF

ORTHOTIC AND PROSTHETICS Dr: Bayakh Azad Ramazan M.B.Ch.B CABMS (Orthopedic and Trauma Surgeon) Council of Arab Board for Medical Specialties GAIT Human gait may be define as “ the translatory progression of the human body as a whole, produced by...

ORTHOTIC AND PROSTHETICS Dr: Bayakh Azad Ramazan M.B.Ch.B CABMS (Orthopedic and Trauma Surgeon) Council of Arab Board for Medical Specialties GAIT Human gait may be define as “ the translatory progression of the human body as a whole, produced by coordinated, rotatory movements of the body segments” is known as gait or human locomotion. Gait is the medical term to describe human locomotion, or the way that we walk. Every individual has a unique gait pattern. GAIT Normal Gait:- Series of rhythmical, alternating movements of the trunk & limbs which result in the forward progression of the center of gravity & the body. There are (4) major criteria essential to walking. Equilibrium: The ability to assume an upright posture and maintain balance. Locomotion: The ability to initiate and maintain rhythmic stepping Musculoskeletal Integrity: Normal bone, joint, and muscle function Neurological Control: Must receive and send messages telling the body how and when to move. (visual, vestibular, auditory, sensori- motor input) Gait Cycle One gait cycle is measured from heel-strike to heel-strike. consists of: stance phase period of time that the foot is on the ground ~60% of one gait cycle is spent in stance during stance, the leg accepts body weight and provides single limb support swing phase period of time that the foot is off the ground moving forward ~40% of one gait cycle is spent in swing the limb advances Stride is the distance between consecutive initial contacts of the same foot with the ground Step is the distance between initial contacts of the alternating feet Stance phase Initial contact (heel strike) occurs when foot contacts the ground muscular contractions hip extensors contract to stabilize the hip quadriceps contract eccentrically tibialis anterior contracts eccentrically Loading response (initial double limb support) Marks the beginning of the initial double limb stance occurs after initial contact until elevation of opposite limb bodyweight is transferred on to the supporting limb Muscular contractions ankle dorsiflexors (tibialis anterior) contract eccentrically to control plantar flexion moment quads contract to stabilize knee and counteract the flexion moment (about the knee) Mid-stance (single limb support) Initial period of single leg support from elevation of opposite limb until both ankles are aligned in coronal plane muscular contractions gluteus medius and calf muscles undergo eccentric contraction Terminal stance (single limb support) Begins when the supporting heel rises from the ground and continues until the opposite heel touches the ground Muscular contractions toe flexors and tibialis posterior contract and are the most active during this phase Pre-swing (second double limb support) Is the start of the second double limb stance in the gait cycle. definition from initial contact of opposite limb to just prior to elevation of ipsilateral limb muscular contractions hip flexors contract to propel advancing limb Swing phase Initial swing (toe off) start of single limb support for opposite limb from elevation of limb to point of maximal knee flexion Muscular contractions hip flexors concentrically contract to advance the swinging leg Mid-swing (foot clearance) Definition following knee flexion to point where tibia is vertical Muscular contractions ankle dorsiflexors contract to ensure foot clearance Terminal swing (tibia vertical) Definition from point where tibia is vertical to just prior to initial contact Muscular contractions hamstring muscles decelerate forward motion of thigh Variables affected during Gait cycle Pelvic rotation pelvis rotates 4 degrees medially (anteriorly) on swing side lengthens the limb as it prepares to accept weight Pelvic tilt pelvis drops 4 degrees on swing side lowers COG at midstance Variables affected during Gait cycle Knee flexion in stance early knee flexion (15 degrees) at heel strike lowers COG, decreasing energy expenditure also absorbs shock of heel strike Foot mechanisms ankle plantar flexion at heel strike and first part of stance Variables affected during Gait cycle Knee mechanisms at midstance, the knee extends as the ankle plantar flexes and foot supinates restores leg to original length reduces fall of pelvis at opposite heel strike Lateral displacement of pelvis pelvis shifts over stance limb COG must lie over base of support (stance limb) Variables affected during Gait cycle Center of gravity (COG) in standing position is 5cm anterior to S2 vertebral body vertical displacement during gait cycle COG displaces vertically in a rhythmic pattern the highest point is during midstance phase lowest point occurs at the time of double limb support horizontal displacement COG displaces 5cm horizontally during adult male step What is an abnormal gait? An abnormal gait is a change to your walking pattern. Everyone’s natural walking style is unique. However, injuries and medical conditions can affect your walking pattern. Anything that affects your brain, spinal cord, legs or feet can change your gait. Gait abnormalities are more common as you age. Around 15% of people experience a gait abnormality by age 60. However, more than 80% of people over age 85 have a gait abnormality. Children are less likely to have a gait abnormality unless they have an underlying health condition or experience an injury What causes gait abnormalities? There are a lot of possible causes of and contributing factors to gait disorders or abnormalities. The most common causes include: Joint pain. An injury (including bone fractures or sprains). Sores on your feet, calluses, ingrown toenails, warts and corns. Shoes that don’t fit properly. What causes gait abnormalities? Inner ear issues. Nerve damage. Vision problems. Some abnormal gaits have more than one cause. What causes gait abnormalities? Underlying health conditions that can cause gait abnormalities include, but aren’t limited to, the following: Parkinson’s disease or parkinsonism. Multiple sclerosis. Stroke. Arthritis. Cerebral palsy. Hemiplegia. Spinal stenosis, herniated disk. What are the symptoms of gait abnormalities? Signs and symptoms of gait abnormalities vary based on which type of abnormality you’re experiencing. Some of the most common symptoms include: Dragging or shuffling your feet. Feeling out of balance when you walk. Stiff muscles or joints in your hips and legs What are the symptoms of gait abnormalities? Swaying side to side with each step (waddle). Walking with your head and neck bent toward the ground. Taking higher than normal steps and dropping your feet with each step. Taking small steps. Pain when walking. What are the risk factors for gait abnormalities? You may be more at risk of developing gait abnormalities if you: Are older than 60. Have a condition that affects your movement, joints, bones, muscles, brain or spinal cord. Experience an injury. What are the types of gait abnormalities? There are several different types of gait abnormalities, the most common include: Antalgic gait: An antalgic gait is the result of pain. It’s the most common type of abnormal gait. It makes you limp (avoiding stepping with or putting pressure on your affected leg or foot). What are the types of gait abnormalities? Propulsive gait (Parkinsonian gait): This type of gait affects people diagnosed with parkinsonism or Parkinson’s disease. Characteristics of a propulsive gait include a stooping, rigid posture and your head and neck bending forward. Your steps are usually short and fast to maintain your center of gravity (festinating gait). Scissors gait: This type of gait gets its name because your knees and thighs hit or cross in a scissors-like pattern when you walk. Your steps may be slow and small. This type of gait usually affects people diagnosed with spastic cerebral palsy. What are the types of gait abnormalities? Spastic gait (hemiplegic gait): A spastic gait causes you to walk with one stiff leg. When you lift that leg to walk, it either drags or swings around in a semicircular motion (circumduction). This type of gait is common among people diagnosed with cerebral palsy, multiple sclerosis or hemiplegia. Waddling gait: A waddling gait causes you to exaggerate the movement of your upper body, which creates a waddling or duck-like walk. Progressive muscular dystrophy or hip dislocation present from birth can produce a waddling gait. What are the types of gait abnormalities? Steppage gait (neuropathic gait): This type of gait causes a high step, where you elevate your hip to lift your leg higher than normal. Your foot may appear floppy when it drops. Your toes usually point down and scrape the ground when you walk. Muscle atrophy or a peroneal nerve injury (like from spinal stenosis or a herniated disc), can cause a steppage gait. What are the types of gait abnormalities? Crouching gait: A crouching gait causes your ankles, knees and hips to flex while you walk. It can look like you’re about to bend down as you’re walking. Your toes may drag. This type of gait is common if you have cerebral palsy. Ataxic gait: This type of gait occurs with cerebellar degeneration. It causes irregular steps that affect your ability to walk in a straight line when you walk heel to toe. You may feel unsteady if you have an ataxic gait. What are the types of gait abnormalities? Shuffling gait: Shuffling is walking without lifting your feet completely off the ground. It causes your feet to drag. You may shuffle if you feel off balance or have an injury that prevents you from lifting your feet off the ground when you walk. Lurching gait: A lurching gait is common among people affected by paralysis or weakness of the gluteus area (the muscles near your hips and butt). It causes a slow and long stride. Your upper body can jerk forward or backward to lessen the weight on your affected leg. What are the complications of gait abnormalities? The complications of gait abnormalities could include: Increased risk of falls or injuries. Muscle weakness. Sudden inability to walk. Pain. Reduction in ability to maintain independence. How are gait abnormalities diagnosed? A healthcare provider will diagnose gait abnormalities during a physical exam. They’ll take a complete medical history, as well as: Assess your muscle strength, tone and coordination. Check the length of your legs (for example, artificial hips can cause different leg lengths). Examine your vision and blood pressure. Examine your neck and spine. Assess your balance. Assess the range of motion of the joints used for walking. How are gait abnormalities treated? Treatment for gait abnormalities varies based on the type of gait and its cause. Treatment options could include: Medications to treat the underlying condition like arthritis, Parkinson’s disease or multiple sclerosis. Resting if you have an injury. Physical therapy and strengthening exercises How are gait abnormalities treated? Surgery, including hip or knee replacements. Using assisted mobility devices, like a cane or a walker. Adjusting footwear (wearing shoe lifts) or using splints or braces. If you have an abnormal gait, your healthcare provider will give you instructions to prevent falls and injuries. LOWER-EXTREMITY PROSTHESES Prostheses for Syme's Amputation: Perhaps the major reason Syme's amputation was held in such disfavor in some quarters was the difficulty in providing a comfortable, sufficiently strong prosthesis with a neat appearance. The short distance between the end of the stump and the floor made it extremely difficult to provide for ankle motion needed.  Most Syme prostheses were made of leather reinforced with steel side bars, resulting in an ungainly appearance. Most Syme prostheses were made of leather reinforced with steel side bars, resulting in an ungainly appearance. Research workers were quick to realize that the use of the proper plastic laminate might solve many of the problems long associated with the Syme prosthesis.