Thigh Flexion & Leg Extensions

Flexion and extension of the leg and thigh are functions performed by separate groups of muscles in the thigh, and extend into the lower leg and abdomen. The actions of flexion and extension are necessary for movements including running, walking and jumping. Building muscles in these area will help your sports performance, and protect the knee joint from injuries like meniscal tears.

  1. Thigh Flexion

    • Thigh flexion refers to the bending of the knee joint to draw the lower leg back and up toward the thigh. You perform flexion daily when walking, or when you bend your knees to sit. A number of muscles located deep within the thigh are responsible for this action. These muscles include the psoas, iliacus, sartorius, adductor longus, adductor brevis and pectineus. Exercises that strengthen these muscle include squats, knee crunches and leg presses.

    Leg Extension

    • Leg extension occurs when the knee is straightened and the lower leg is moved away from the back of the thigh. The quadriceps muscles in particular are responsible for leg extension. The quadriceps refers to a group of four muscles, the vastus rectus, vastus intermedius, vastus lateralis and vastus medius, all of which are located in the thigh. Exercises to build the quadriceps include sitting or standing leg extensions and lunges.

    Squats

    • Squats are a great exercise to strengthen and build the thigh muscles, which aid in flexion and extension. To execute a squat, stand upright with a straight back and your arms at your sides. Position your feet shoulder-width apart. Bend at the knees to gradually lower your bottom toward the floor while keeping your back straight and chest upright. As you lower, raise your arms to extend in front of you for balance. Hold the lowered position for a few seconds before slowly returning to the starting position. Perform three sets of 10 to 15 repetitions. To add more of a challenge, try holding hand weights during this exercise.

    Sitting Leg Extensions

    • This exercise develops strong quadriceps to help protect the knee joint from excessive strain during sports. To perform leg extensions, sit on a sturdy chair with your back straight and your arms at your sides. Your hands can either be used to brace you on the seat of the chair or be folded in your lap. Slowly lift one leg from the knee so that the leg is straight and the calf is parallel to the floor. Hold for a few seconds before gently lowering it back to the starting position. Repeat with the other leg. Perform three sets of five to 10 repetitions on each leg. To add difficulty to this exercise, wear ankle weights.