Biomechanics 1 final exam USAHS already passed

Biomechanics 1 final exam USAHS already passed How much dorsiflexion is needed to navigate stairs? What about walking? Walking- neutral; Stairs 20 degrees What nerve innervates the dorsiflexors? Deep peroneal What nerve innervates the plantarflexors? Tibial nerve Supraspinatus origin, insertion, action, and innervation Origin: supraspinous fossa of the scapula Insertion: superior facet of the greater tubercle of the humerus and the capsule of the shoulder joint Action: abducts and externally rotates the humerus and stabilizes the humeral head Innervation: suprascapular (C5,C6) Infraspinatus origin, insertion, action, and innervation Origin: infraspinous fossa of the scapula Insertion: middle facet of the greater tubercle of the humerus and the capsule of the shoulder joint Action: external rotation of the humerus and stabilizes the humeral head Innervation: suprascpaular (C5,C6) Teres minor origin, insertion, action, and innervation Origin: axillary border of the scapula Insertion: lower facet of the greater tubercle of the humerus and the capsule of the shoulder joint Action: external rotates the humerus and draws it toward the glenoid cavity Innervation: axillary nerve (C5) Subscapularis origin, insertion, action, and innervation Origin: subscapular fossa of the scpaula Insertion: lesser tubercle of the humerus and the joint capsule Action: internally rotates the humerus and stabilizes the humeral head Innervation: upper and lower subscapular nerves (C5,C6) 1st MTP flexion/extension during gait Ext. 65; Flex. Not sure What is steppage gait? weak dorsiflexors lead to foot drop causing compensatory excessive hip and knee flexion during gait (Occurs in stroke patients) What problems arise from an increased Q angle Increased lateral tracking of the patella Q angle for males vs females Females- typically 17 degreees (less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flex) Males- typically 12 degrees (less than 18 degrees with the knee in extension and less than 8 degrees with the knee flexed to 90 degrees) How is the Q-angle measured? From ASIS to midpoint of patella to the tibial tubercle How does a person vary their gait speed? Stide length and step length Stride length vs step length Step- one foot touches and then the other foot Stride- the same foot after going through a full gait cycle When does subtalar pronation occur during gait? Foot flat and mid stance What nerve supplies the glute max? Inferior gluteal (L5, S1, S2) Patella Baja vs patella alta Baja the patella is abnormally low, Alta the patella is abnormally high What are the four types of heel-strikes? Splatfoot, rearfoot, midfoot, and forefoot How is the first ray involved in triplanar motion? Peroneus longus attaches to the first ray Screw home mechanism of the knee As the length of the medial femoral condyle is longer than the length of the lateral condyle, the tibia rotates externally about 15° on the femur during the last 20° of extension. Genu varum vs genu valgum Varum- bow legged Valgum- knock kneed Coxa vara vs coxa valga Vara- <120 Valga- >135 Normal is 120-135 _____ ___________ of anteversion is normal. Any less is considered retroversion and anymore is considered excessive anteversion. 12-15 degrees True or false: 8 degrees of anteversion is considered retroversion. True Tight hip flexors pull the pelvis into a(n) __________ tilt. Anterior What muscles IR the hip? Which is most powerful? TFL, gracilis, glute med/min, and the adductors (not sure most powerful i think add mag) What muscles ER the hip? Which is most powerful? Glute max is most powerful Glute max, piriformis, obturators, gemelli, quadratus femoris True or false: The piriformis is an ER until 90 degrees of hip flexion then it becomes an IR. True Actions of glute medius Abduction and IR of the hip (superior gluteal L4, L5 S1) During a forward bend the glute max contracts _____________. Eccentrically At what degree do the hip and knee experience the most external torque in a squat? Trendelenburg gait Weak abductors, particaularly glute med. causes leaning toward weak side during gait Other deviations Vaulting gait Subtalar closed chain pronation Midfoot: pronated Forefoot: supinated A ___________ foot is more rigid. Supinated What are the traditional and rancho terms for the swing phase? Traditional- acceleration, midswing, deceleration Rancho los amigos- initial swing, midswing, terminal swing What are the ground reaction forces during the heel-strike (initial contact) phase? Ankle plantarflexion, knee extension, hip flexion What are the ground reaction forces during the foot-flat (loading response) phase? Ankle plantarflexion, knee flexion, hip flexion What are the ground reaction forces during the mid-stance phase? Ankle dorsiflexion, knee extension, hip extension What are the ground reaction forces during the heel off (terminal stance) phase? Ankle dorsiflexion, knee extension, hip extension What are the ground reaction forces during the toe off (pre-swing) phase? Ankle dorsiflexion, knee flexion, hip extension Hip extension ROM for walking? 30 Hip flexion ROM for walking? 30 How many degrees of plantarflexion are required for walking? 20 What are the three stance phases in climbing stairs? Weight acceptance, pull up, forward continuacne What are the two swing phases when climbing stairs? Foot clearance, foot placement ________ ________ is the traditional term for initial contact. Heel strike ________ _______ is the traditional term for the loading response. Foot flat _______ _______ is the traditional term for mid stance. Mid stance (these are the same) ______ _____ is the traditional term for terminal stance. Heel off _____ _____ is the traditional term for pre swing. Toe off How much knee flexion is needed for walking? 60 Ground reaction forces acting during mid stance of gait? Hip: extension Knee: extension Ankle: dorsiflexion