15- MM during gait Flashcards
What are the 4 main functions of muscles?
- Prime mover of body segments
- Proprioception
- Controlling movement of body segmenets
- Stabilization of joints
What are the 3 roles of glut max in gait?
- Late swing: acts eccentrically to decelerate flexion of the hip
- Early stance: acts concentrically to initiate extension of the hip
- Toe-off: acts concentrically to assist in abducting the swing phase leg
What is the main role of glut med and min throughout the gait cycle? What are the key differences in their roles?
Frontal plane stabilization
Med: turns on at toe-off to provide abduction and int rot
Min: turns on at mid-swing to provide additional internal rotation
At which point in gait do the hamstrings demonstrate peak activity? Why?
Terminal portion of swing phase to decelerate forward motion of extending leg (avoid hyperextension of knee)
At which point in gait do the quads demonstrate peak activity? Why? When do they turn off?
Early contact to decelerate knee flexion
Turn off when gravity line passes anterior to the knee joint (now gravity produces extension moment)
Which anterior thigh muscle acts only during swing phase? What does it do?
Sartorius - knee flexion and internal rotation of the tibia
Which 2 muscles do the hamstrings assist during gait? How?
- Glut max: decelerating hip flexion/initiating hip extension
- Gastroc: flexing knee
Why does the tibia need to be internally rotated during swing phase?
So that initial contact is in a pronated position
At which point in gait do the adductors demonstrate peak activity? Why?
Toe off to flex and internally rotate the femur during swing phase
Also turn on during late swing to prepare for ground reaction forces
Which muscle helps stabilize the insertion of glut max during the contact period?
TFL
What are the 2 key roles of tib ant in gait? Which other 2 muscles have the same role?
- Swing phase: acts concentrically so toes clear the ground
- Stance phase: acts eccentrically to slowly lower forefoot to ground after initial contact
EHL, EDL
Why do overpronators tend to get anterior shin splints?
Tib ant plays a role in slowing the rate of pronation during gait - overpronation makes it so tib ant needs to turn on more
What is the main role of gastroc in gait?
Produce heel lift during stance phase
Which of the following are functions of tibialis posterior during gait?
A. Supinate the subtalar joint late in stance phase
B. Slows down the rate of plantarflexion during early stance phase
C. Allows the toes to clear the ground during swing phase
D. Slow down the rate of pronation in stance phase
A and D
What are the 2 main roles of soleus during gait?
Both during stance phase
- Prevents forward motion of proximal tibia
- Produces heel lift
Which of the following muscles assist in returning the subtalar joint to neutral andthen a supinated position late in stance? A. Tibialis posterior B. Tibialis anterior C. Flexor digitorum longus D. Flexor hallucis longus
A, C, and D
What are the 2 main roles of popliteus during gait?
- Initial contact: Assist subtalar joint with pronation by internally rotating tibia
- Midstance: assist gastroc with decelerating knee extension to prevent hyperextension
Dr. Ross said that this muscle group is responsible for resisting subtalar joint supination and if it wasn’t working, you would sprain your ankle every step you take.
Peroneal muscles
Which peroneal muscle is responsible for preventing splaying of the tarsals during late midstance and early propulsion?
Longus
Which peroneal muscle is responsible for creating a stabilizing compressive force as it pulls the fifth metatarsal into the cuboid and calcaneus?
Brevis
Which 2 muscles are important in stabilizing the 1st ray against the ground and in the transverse plane?
Abductors hallucis
Adductor hallucis
True or false: The function of the intrinsic muscles of the foot is to act as prime movers of the greattoe and the lesser toes
False - they stabilize the foot to act as a rigid lever
