Single Leg Loadbearing Flashcards
What joints are involved in SL LB
Hip
Knee
Ankle
What movements happen at each joint involved in a SL LB
Hip - neutral > flexion
Knee - extended > flexion
Ankle - plantar grade > dorsiflexion
What are the axes and planes at each joint movement in step down
Sagittal plane and frontal axis
What muscles work in the hip flexion, knee flexion and ankle dorsiflexion during step down
What type of muscle contraction as well
Hip flexion - agonist > rect fem and illiopsoas concentrically initiate movement
Antagonist > glute max eccentrically
Knee flexion - hamstrings concentrically, quadriceps eccentrically
Ankle dorsiflexion - tibialis anterior concentrically
Gastroc and soleus control eccentrically
What range does glute max work across the hip in a step down
Inner to middle range
What range do the single joint quad muscles operate across the knee in a step down
Hip flexion rect fem range?
Range of hamstring in knee flexion
Ankle dorsiflexion Tib ant range?
Inner to middle range
Mid to inner
Mid to inner
Mid to inner
What type of muscle contraction occurs around the weight bearing ankle in a step down
Eccentric contraction
How does an eccentric muscle contraction relate to torque?
Main function of a eccentric muscle contraction is to control or decelerate movement which = negative work ???
How does the calcaneous impact torque and why does it provide mechanical advantage?
Impacts the anatomical torque as its a bony prominence so increases the lever arm and therefore the PD and increases torque - this provides a bio mechanical advantage as there is a longer effort arm, it requires less force and increases the efficiency of torque
Example of 2nd class lever with one of the joints involved in the step down (doesn’t need to relate to step down)
Ankle - standing on tip toes
Fulcrum - metotarsalphalangeal joints
Effort - Gastroc insertion on calcaneous
Load - body weight on tibia bone
What position puts the Gastroc at potential passive insufficieny but why does this not happen in a step down?
Passive insufficiency is the inability of an MTU to lengthen adequately to allow full range of motion to occur, this could potentially happen in the gatsocnemius when legs are straight and we try to touch toes but it doesn’t happen in a step down because the gastrocnemius is lengthening across the ankle and shortening across the knee
Any examples of eccentric loading in step down?
Any muscles working in origin - insertion reverse in a step down?
Tibialis anterior - origin moves to insertion on the foot in a squat down movement (closed chain)
3rd class lever with one of the joints involved in a step down
At the hip joint the glute max in a sit to stand
