Your biceps and quadriceps both have a secret. Although each of these muscles is primarily responsible for a single joint movement -- elbow flexion for the biceps, knee extension for the quadriceps -- they each assist with a second joint movement. The biceps also acts as a weak shoulder flexor, and one of your four quadriceps muscles assists with knee flexion.
What This Means
The implication of this "secret" is that to fully stretch your biceps, you must not only straighten your elbow but also extend your shoulder. To fully stretch all of your quadriceps muscles, you must not just bend your knee but also extend your hip.
Standing Quadriceps Stretch
You can perform this stretch anywhere you have something sturdy to hold onto for balance. Stand on one leg and grasp the other leg in your same-side hand, drawing the heel up toward your buttock on that side. Keep your bent knee close to your body; it should point straight down. This targets three of your quadriceps muscles -- the vastus lateralis, vastus intermedius and vastus medialis -- and if you press your hip slightly forward, you'll also stretch your fourth quadriceps muscle, the rectus femoris. You may also feel a stretch in your hip flexors if they're tight.
Lying Quadriceps Stretch
If you find stretching your quads while standing to be a struggle, you can also stretch lying in bed or on the floor. No matter how you're oriented, you must perform the same set of motions: knee flexion and hip extension. Lie on your left side to stretch your right leg, grasping your heel and drawing it in toward your buttock as if you were standing.
Standing Biceps Stretch
One of the simplest biceps stretches targets both your chest and the front of your shoulder, too -- no coincidence, given the biceps' secret role as a weak shoulder flexor. Stand in a doorway and reach out to your side with one arm at shoulder level, palm facing forward. Rest your palm against the wall beside the doorjamb and gently turn away from it, moving your feet so your entire body turns, until you feel a stretch in your chest, shoulder and upper arm. Hold for 10 to 30 seconds before repeating on the other side.
Seated Biceps Stretch
If you find the standing biceps stretch uncomfortable on your shoulder, try sitting down on a bed or an exercise mat. Bend your knees and plant both feet on the floor in front of you. Place your hands on the floor beside your hips, arms straight, fingers pointed back. Scoot your hips forward -- moving your feet forward to make room, if necessary -- and leave your hands in place, "walking" away from them until you feel a biceps stretch.
