Question

For the following two movements, compare (a) the type of kinematics (i.e., proximal-on-distal or distal-on-proximal segment) and (b) the relative demands placed on the quadriceps muscles.

• First movement: From a deep squat position, come to a standing position.

• Second movement: From a seated position, straighten out the leg.

Answer 1

A squat is a strength exercise performed by trainee in which lowers their hips from the standing position and then stands back up. During descent of a squat, the hip joint and knee joint flex while the ankle joint dorsiflex; conversely the hip and knee joints extend and the ankle joint plantarflexes when standing up. Squats are one of the best exercise for increasing the strength and size of the lower body muscles as well as developing core strength. Dring the squat quadriceps muscles are used primarily. The squat also isometrically uses the spine and the abdominal muscles, among others.Squat is one of the 3 lifts in strength sport of power lifting, deadlift & the bench press. Quadriceps muscle is good extension muscle of the knee, forming a large fleshy mass which covers the front and sides of femur.
All four quadriceps are powerful extensors of the knee joint. They are crucial in walking, running, jumping and squatting. Because the rectus femoris attaches to the ilium, it is also a flexor of the hip. This action is also crucial to walking or running as it swings the leg forward into the ensuing step. The quadriceps, specifically the vastus medialis, play the important role of stabilizing the patella and the knee joint during gait.