Upper Extremities Parts  Shoulder Girdle  Shoulder Joint  Elbow Joint  Radioulnar Joint  Wrist Joint

Muscle Contribution to Joint  Stronger Muscles = More Joint Stability  Angles of Pull influence Joint Stability  Stabilizing Angles = < 90  angle of pull  Dislocating Angles = > 90  angle of pull

Shoulder Girdle  Involved in Reaching/Grasping Motions  Designed for Mobility  Unstable joint  Strength of Muscles VERY important

Shoulder Joint Involved in a wide variety of motions Designed for Mobility, Unstable joint Rotator Cuff & Deltoids = small angle pull Wheel-Axle Mechanism

Overarm Throw Pattern  “cocking action” = extreme lateral rotation  rapid medial rotation and protraction  Strengthen Medial Rotators BOTH Concentrically and Eccentrically

Elbow Joint  Only Flexion and Extension  Stable joint due to bony structure  Muscle arrangement = stabilizing effect

How to Strengthen Elbow Extensors Elbow Extensions with shoulder flexed figure 2.5e on page 61 Elbow Extensions with shoulder flexed figure 2.5e on page 61 Shoulder Hyperextensions with elbow extended figure 2.5d on page 61 Shoulder Hyperextensions with elbow extended figure 2.5d on page 61

3 Ways to Strengthen Elbow Flexors 1. Elbow flexion from anatomical position 2. Elbow flexion with shoulder Hyperextended 3. shoulder flexion figure 2.5j on pg 62 

Radioulnar Joint  Unstable due to weak bony arrangement  Pronate = turn inward [medial] away from anatomical position  Supinate = turn outward [lateral] back toward anatomical position figure 5.12 left side of picture pronated page 185 right side of picture supinated

Wrist Joint  MSDs - musculoskeletal disorders 1. angle of the work surface 2. position requirements of the work 3. magnitude & direction of applied forces 4. Degree of repetition  CTS - Carpal Tunnel Syndrome  see Force guidelines per task on page 189

Hip Joint  Medial rotation involved in kick, throw & strike  Wheel-Axle - figure 6.5 and 6.6 [page 197] A: medial B: lateral hip rotation

Hip Joint  Bending/Stooping = increase FA resistive  to achieve equilibrium, hip extensors must provide high Tension/Force [hams, back] FIG 9-30 page 296 “Basic Biomechanics” 4 th Edition by Susan J. Hall

Knee Joint Biarticulate Muscles - work knee and hip Muscular Imbalances: 1. Hams - lateral vs. medial lateralis 2. Quads - vastus lateralis and medialis Positions for potential injury 1. Foot fixed while hip/trunk rotates 2. Squats [FIG 6.11 pg 204] 3. Whip kick in Breaststroke [FIG 6.12 pg 205]

Knee Joint: Potential Injury Positions page 205

Knee Joint: Potential Injury Positions turning the body while foot is fixed FIG 6.8 page 200

Knee Joint: Potential Injury Positions Deep Squat changing axis of rotation from knee joint to calf/thigh area FIG 6.11 page 204

Knee Joint: Potential Injury Positions rehabilitation of knee injuries page 260: studies on ACL stress, shear forces, petellofemoral contact

ANKLE JOINT  Bony arrangement = stability  Ligaments play major role in stability  flexion = dorsiflexion  extension = plantar flexion FIG 6.13 page 207

SUBTALAR JOINT  allows foot to navigate uneven surfaces  inversion (sole in) and eversion (sole out)  inversion with plantar flexion  eversion with dorsiflexion FIG 6.15 page 209 Inversion during Plantar Flexion

Muscles of Ankle & Foot  Strength important on all sides  Muscular imbalance = misalignment  misalignment = line of g eccentric to joints  weak dorsiflexors may cause shin splints  overdeveloped inversion/plantar flexion muscles = prone to lateral ankle sprains

Stretching Achilles Tendon  Preventative measure for shin splints  Achilles tendon = extension of both gastrocnemius and soleus muscles  2 dorsiflexion stretches: 1. with knee extended 2. with knee flexed

Plantar Fasciitis  Overuse Syndrome injury  overload of stress at insertion of plantar surface fascia on calcaneous  chronic therapy involves: 1. Strengthen plantar & dorsiflexors 2. Increase ROM in dorsiflexion see page 210 re Kibler et al study

LOCOMOTION Walking Running Long support phase [65%] always support phase Shorter support phase non-support phase F vertical = 3 x body wt

Ideal Alignments: LEG  Lower extremities like columns supporting a roof  Ideally as vertically aligned and as straight as possible to support the forces from above FIG 6.19 page 213

Ideal Alignments: FOOT FIG 6.20 page 214 a is Ideal FIG 6.21

Leg Length Inequities  Anatomical - due to bone structure  Functional - due to tilted pelvis  Environmental - due to uneven ground

TORSION Femoral Tibial Femur rotated medial medial facing patella frequent in FEMALES treatment: 1. Strengthen lateral hip rotators 2. Stretch medial hip rotators Tibia rotated lateral lateral facing patella frequent in MALES treatment: - muscular balance in all 3 hamstrings must be developed

VARUS  INWARD angle from proximal to distal  lateral stress is proximal  medial stress is distal

VALGUS  OUTWARD angle from proximal to distal  medial stress is proximal  lateral stress is distal

Key Features of Good Shoes Heel well cushioned Heel Counter firm Arch Support firm Sole Width reasonable for stability Forefoot flexible & cushioned Toe Box with reasonable room Traction, Durability, Permeability