The sartorius' usual claim to fame is being the longest muscle in the body. It crosses both the knee and hip joints, and is used when sitting cross-legged. вЂњSartorius" is Latin for вЂњtailor,вЂќ as the cross-legged position was once popular with tailors. To strengthen the sartorius, you must do exercises that involve flexing the hip or knee or using the sartorius as a stabilizer.
Location and Functions of the Sartorius
Starting at the ilium, the sartorius runs diagonally across the front of the thigh to insert at the medial tibia, that is, on the inner side of the knee. This two-joint muscle plays a role in both knee and hip flexion, but is stronger when doing one of these functions at a time. In conjunction with other muscles, the sartorius internally rotates the knee and externally rotates the hip.
Resisted Knee Lift
To strengthen the sartorius, along with the other hip flexors, you can do a resisted knee lift. You'll need a resistance band, the type that is a continuous loop like a giant rubber band, not the kind with handles. Put your left foot inside the loop, anchoring it to the floor. Your right foot also slips inside the loop. Lift your right knee as high as you can, working against the loop's resistance.
Seesaw with Ball
The sartorius is also involved in stabilizing the hip joint, as you will find in this exercise. Stand up tall, holding a Swiss ball over head, your feet shoulder-width apart. Now hinge forward onto your right leg, extending the left one behind you, until your body is parallel to the ground. Stand back up. Repeat, and switch sides. Along with other muscles, your sartorius in the standing leg will work hard to stabilize you.
Standing Quad Stretch
The standing quad stretch, familiar to both yogis and runners, also works the sartorius as a hip stabilizer. Stand on your right leg. Bend your left leg behind you, bringing the foot up towards your buttock. Reach down and grasp your left foot, then pull the foot in closer to your buttock to stretch the left thigh. Repeat on the other side. This one does double-sartorius duty. You'll strengthen the standing leg, and stretch your sartorius in the lifted leg.