MSK Anatomy, Biomechanics, and Injuries Flashcards
What structures are present in the anterior compartment?
- Deep peroneal nerve
- Anterior tibial a+v
- Tibialis anterior
- EHL
- Peroneus tertius
What structures are in the deep posterior compartment?
- Tibialis posterior
- Flexor digitorum longus
- Posterior tibial a+v
- Tibiali nerve
- FHL
(Tom, Dick, and A Very Nervous Harry)
What structures are in the superficial posterior compartment?
- Medial and lateral head of the gastroc
- Soleus
- Plantaris
What structures are in the lateral compartment?
- Peroneus brevis
- Peroneus longus
What provides forward motion during running?
Swinging leg and arm
What provides momentum during walking?
Stance leg
What muscles are activated during the swing phase of running?
Rectus femoris and iliopsoas (flex hip –> forward motion)
What muscles prepare the leg for stance phase of running?
Hamstring and glutes
How many float periods exist per stride?
Two
What is the foot contact pattern for most individuals during slow running?
Heel to toe
How does foot contact pattern change as velocity of running increase?
Foot will strike either with forefoot and heel simultaneously, or with forefoot only
What are signs and symptoms of PIN syndrome?
- PIN = pure motor branch –> presents with wrist extension weakness (difficulty opening door, grabbing cup)
- sensory distribution should be intact
What occurs during the windup phase of pitching?
The body rotates so that the hips and shoulders are perpendicular to the target and flexion of the lead hip raises the center of gravity. The shoulder muscles are relatively inactive.
What occurs during the early cocking phase of pitching?
Potential energy is stored without much stress on the shoulder joint.
What occurs during late cocking phase of pitching?
Potential energy is stored to be used during the acceleration phase. Late cocking involves terminal external rotation of the shoulder with eccentric stressing of the internal rotators of shoulder and mild stretching of the anterior capsule. It ends with planting of the lead foot.
What occurs during the acceleration phase of pitching?
Subscapularis internally rotates the shoulder to begin propelling the ball forward.
What occurs during the deceleration/follow through phase of pitching?
Ball is released and leftover energy is dissipated and results in the pitcher in a fielding positions
What causes backpacker’s palsy and how does it present?
- Brachial plexus traction injury
- presents wtih UE numbness, weakness, and atrophy and typically effects upper trunk
What is the glide/reach phase of freestyle swimming?
hand enters water with shoulder in full flexion lateral to midline of body
What is the early pull-through phase of freestyle swimming?
hand reaches perpendicular to long axis of body at 90 degrees of forward flexion
What is the late pull-through phase of freestyle swimming?
from 90 degrees of forward flexion until hand exits water with shoulder extension
What is the recovery phase of freestyle swimming?
hand out of water, elbow flexed, forward flexion, and internal rotation of glenohumeral joint
Which phase of freestyle is most susceptible to supraspinatus injury?
Recovery phase
What is intersection syndrome?
Overuse injury in which first extensor tendon compartment crosses over second compartment around 4-8cm proximal to Lister’s tubercle causing friction
What is cyclist’s palsy?
Ulnar neuropathy at Guyon’s canal - commonly due to improper grip size, infrequent hand changes, bumpy terrain, improper suspension
What causes little league elbow and how does it present?
- Medial elbow experiences a tensile load and lateral elbow undergoes compressive forces
- Presents with medial elbow pain in early acceleration phase and posterior elbow pain during deceleration and follow through
What specific exercise can help contractures of posteroinferior capsule found in GIRD?
Sleeper stretch
What kind of rehab can help reduce incidence of new and recurrent hamstring injuries?
Eccentric training of hamstrings
How should type I radial fractures be treated?
Sling for 1-2 weeks followed by early ROM
What are risk factors for SCFE?
Age 10-14yo, obesity, AA, recent growth spurt, male gender
How can SCFE present?
gradual pain with limp, knee pain, decreased/pain with IR (+/- abduction and hip flexion)
What spinal curvature in pts with scoliosis should you consider bracing?
> 20 degrees
What activities are off limits for pts with scoliosis wearing a brace?
Trampoline and contact sports
What nerve root is most vulnerable to nerve injury and what motor strength should be tested?
C5 - shoulder abduction, ER, and elbow flexion
C5 sensation - to elbow, C6 - to thumb
What structures comprise the quadrilateral space and what structures run within it?
Comprised of:
- teres minor superiorly
- teres major inferiorly
- long head of the triceps medially
- humeral head laterally
Contains:
- axillary nerve
- posterior circumflex artery
What structures insert into the intertubercular groove of the humerus?
pec minor, teres major, and latissimus dorsi
What part of the UCL is responsible for most of the valgus stress of elbow?
Anterior bundle of UCL - posterior bundle is only a restraint in flexion greater than 55 degrees
What artery supplies blood to the ACL and PCL?
Middle geniculate artery
What arteries supply the menisci?
Medial and lateral geniculate arteries
What is guyon’s canal comprised of?
piso-hamte ligament, pisiform, hamate, and volar carpal ligament
How might cyclist’s palsy present?
weakness of ulnar hand intrinsics: hypothenar muscles, interossei, third and fourth lumbricals, and adductor pollicis.
What nerve roots contribute to knee extension and leg adduction
L2 and L3
What nerve roots contribute to ankle dorsiflexion?
L4 and L5
What nerve roots contribute to ankle eversion
L5
What nerve roots contribute to ankle plantarflexion?
S1 and S2
What nerve roots contribute to hamstring flexion?
L5 and S1
