Movement Analysis - Blog 1

Every day I sit on the toilet to use the restroom. My starting position is standing. To sit down, I will flex my hip and flex my knee. I will slowly decelerate until I reach the toilet. The hip flexor muscles act as the prime mover for sitting.  Since my body is moving towards the ground, the quadriceps and hip extensor muscles perform an eccentric contraction. The osteokinematics of the knee joint when sitting are extension to flexion and act in a open kinematic chain. To stand back up, I lean forward and transition my weight. I will push up by extending my trunk, then continue to fully extend my hip and knee. The prime mover for hip extension is the gluteus maximus. The motions of flexion and extension take place in the sagittal plane about the frontal axis. In terms of arthrokinematics, the knee joint follows the convex on concave rule. The moving femur is round so it will roll posteriorly and then slide anteriorly.