It's obvious that your muscles contract when you kick into a handstand or move through a series of vigorous Sun Salutations. Perhaps less obviously, your muscles may also contract when you hold a stretch without moving. Getting savvy about muscle contractions will help you relax tight muscles and get more out of your yoga practice.
There are three kinds of muscle contractions. When a muscle shortens as it contracts, that's a concentric contraction. For example, when you stand up from Utkatasana, or Chair pose, the quadriceps muscles on the front of your thighs contract concentrically to straighten your knees. When you lower into the pose, the same muscles contract to keep your knees from bending too quickly, but now they're lengthening as they contract. A lengthening, or stretching, contraction is called an eccentric contraction. If you stay in the pose, the quads still contract, but now there's no movement. They're contracting isometrically to resist the pull of gravity. In fact, you'll probably feel them burning more when you hold the pose than when you stand up.
You use all three types of contractions in yoga. When you move against gravity, your muscles work concentrically. As you stand up from Uttanasana, or Standing Forward Bend pose, your hamstrings, glutes and back muscles contract concentrically to bring you upright. The same muscles contract concentrically to lift your legs toward the ceiling in Sirsasana, or Headstand. Your shoulder muscles contract concentrically to lift your arms overhead as you come into Virabhadrasana I, or Warrior I.
When your muscles resist gravity in movement, they're contracting eccentrically. As you fold forward into Uttanasana, you probably feel a stretch in your hamstrings and back muscles. It may seem counter-intuitive that those muscles contract as they stretch. However, if they didn't contract, you would fall forward rather than lowering with control. Likewise, the shoulder muscles you use to lift your arms overhead in Virabhadrasana I contract eccentrically as you lower your arms. Without that eccentric contraction, they would just drop.
Holding a yoga pose involves isometric muscle contractions. As you hang over your legs in Uttanasana, your back and hamstring muscles contract isometrically to resist the stretch. To help them relax, Iyengar yoga teacher and physical therapist Julie Gudmestad, writing in "Yoga Journal," suggests placing your hands on yoga blocks if they don't reach the floor. With the weight of your upper body supported by your arms, your contracted hamstrings will be able to let go. Gudmestad also recommends contracting your quads isometrically in Uttanasana to help your hamstrings relax.
- The Key Muscles of Yoga; Ray Long
- Yoga Anatomy; Leslie Kaminoff and Amy Matthews
- Yoga Journal: Thigh Master
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