Kinesiology of Lower extremity Flashcards
What movement are the anterior hip muscles responsible for? What are the muscles included?
Hip flexion. The muscles that act as prime movers for hip flexion include the sartorius, and iliopsoas which is a combination of the iliacus, psoas major/minor muscles, rectus femoris, and tensor fasciae latae.
Why does our lumbar spine have a high chance of injury during leg raises? How do you stretch the psoas muscle?
The psoas major/minor muscles are responsible for lifting the legs, due to their origin and insertion, which is on the lumbar spine, their lever of motion is relatively short, needing to exert a large amount of force to lift the leg. To counter this force, abdominal muscles are needed to counter balance the force produced by the psoas muscles, but in most individuals, this abdominal force is insufficient, resulting in many injuries around the lumbar spine including psoas tightness, lordosis, hyperextension/extension of the lumbar spine.
To stretch the psoas, do a forward lunge position with posterior feet on the ground and flex the abdominals for 15 seconds.
What is the function of the rectus femoris?
It crosses both the knee and hip joint hence produces hip flexion and knee extension or both at the same time such as doing standing straight leg raises.
What is the function of the sartorius? (3 at the hips and 2 at the knees)
It flexes, externally rotates, and abducts the hips while internally rotating and flexes the knees
What is the function of posterior hip muscles? What muscles are included? When working eccentrically, what do they do?
The posterior hip muscles are hip extensors, they contain the hamstring group(Semitendinosus, semimembranosus, and the bicep femoris) as well as the gluteus maximus.
When working eccentrically, they also control hip flexion.
What is the function of lateral hip muscles? What do they include?
They function as abductors and external rotators of the hips. They are found posterior and lateral to the hip joint and are referred to as the buttocks. They contain the 3 gluteal muscles, gluteus medius, gluteus minimus and gluteus maximus, they are also assisted by the tensor fascia latae. They originate on places superior to the hip joint hence when working concentrically they pull the hips away from midline resulting in abduction.
What action is caused when a muscle crosses a part of a joint?
Anterior: Flexion
Posterior: Extension
Lateral: Abduction
Medial: Adduction
These principles apply to most major joints except the knee and ankle.
Where do the anterior and posterior fibers of the gluteus medius attach to and what function do they play?
The anterior fibers are attached medially to the axis of hip joint hence plays a role in internally rotating the hips during concentric action.
The posterior fibers are attached laterally to the axis of hip joint hence plays a role in externally rotating the hips during concentric action.
What are the 6 deep external rotators of the hips aside from the gluteus medius? When are they used when the gluteus medius is the primary external rotator?
The 6 muscles include piriformis, superior gemellus, obturator internus, inferior gemellus, obturator externus and quadratus femoris.
The optimal arc of motion for external rotation is 0-40 degrees, anything more requires the 6 muscles to be prime movers.
If the muscle is moving against the pull of gravity what is it doing? And if the muscle is moving with the pull of gravity what is it doing?
Concentrically and eccentrically.
