Hamstrings and Yoga

Hamstring Anatomy and Description

Before looking at the hamstrings and their place in yoga practice, it's worth considering thigh anatomy and the different muscles involved. 

Hamstrings refer to a group of muscles and tendons located at the upper leg's back. There are three hamstring muscles; the biceps femoris, semitendinosus, and semimembranosus. They have a three-fold function, namely to:

• Extend the hips (bridge pose).
• Flex the knee joint. 
• Move the leg.

The hamstrings are primarily employed in actions such as running and walking. Like most other muscles in the body, the hamstrings also have origins and inserts, which are where they are attached to the skeleton. The hamstring muscles originate in the ischial tuberosity of the hip (sitting bones) and the linea aspera of the femur (upper leg bone). 

All three muscles run down the back of the thigh to their various insert points. The sciatic nerve also supplies them. 

Biceps Femoris

The biceps femoris is located on the outer edge of the thigh. It's a two-headed muscle with a long and short head. The long head is attached to the sitting bone, and the small head is connected to the lower part of the femur. 

The long and the short heads have inserts on the tendon of the outer knee, called the fibula. The biceps femoris extends the hip and bends the knee. You can stretch it during forward folds where the legs are close to each other or close to the midline, such as seated forward bends, standing forward bends, pyramid pose, monkey pose,  standing splits, etc.

Semimembranosus

Like the other hamstrings, this muscle originates at the sitting bones. At its origin, it is a thick and membranous tendon. This muscle inserts on the inner knee and has three primary functions, namely:

• To serve as the fascial anchor for the adductor Magnus, the most significant inner-thigh muscle,
• To extend the hip.
• To flex the knee.

Semitendinosus

The semitendinosus originates at the sitting bones and inserts on the superior part of the medial tibia, which is the front of the knee. 

This muscle extends the hip as well as knee flexion. To stretch both semimembranosus and semitendinosus, you must focus on wide-legged forward bends such as upavistha konasana or Janu sirsasana.

Why do You Need Hamstrings?

Your hamstrings muscles are necessary to perform many basic movements, including running, jumping, and walking. At the start of each step, the hamstrings flex the knee and extend the hip. In decelerating knee extension, the hamstrings work against the quadriceps muscles, which lock the knee. 

Hamstring Injuries

A hamstring injury can either be a pull, partial, or complete tear. Since hamstrings are muscles, these injuries are graded from one to three, with one being a mild strain with a relatively short healing time expectancy and three being a complete tear that can take weeks or months to heal. 
Most hamstring injuries are caused by muscle overload. If you force yourself into an intense stretch with tight hamstrings or when you extend a load-bearing muscle, you lengthen the tissue while it is busy contracting. These injuries are often called "eccentric contractions."

Risk Factors for Hamstring Injury

A muscle imbalance can increase your risk of a hamstring injury. A muscle imbalance is when a muscle group is more vital than its antagonist muscle group (opposite muscles). If your quadriceps muscles at the front of your thigh are more robust than your hamstring muscle group, the imbalance can result in muscle strain. 

You may also be vulnerable to muscle strain if your muscles are tight. To prevent stress from muscle tightness, do stretching exercises or Yin Yoga for the hamstrings daily.
Several specific activities and athlete age groups carry an inherent risk of a hamstring injury. If you are:

• An athlete that participates in team sports like football, basketball, or lacrosse, 
• A runner,
• An adolescent athlete that hasn't stopped growing, or
• A dancer, 
  

You may be at a higher risk of a hamstring injury. Teenagers who go through growth spurts are particularly vulnerable to a hamstring injury as their skeletons grow faster than their muscles. (Hamstring Injury, n.d.)

Relationship Between Strength and Flexibility

If you're an advanced yoga practitioner, you may find that one deep stretching with forwarding folds is often challenging to achieve. Many yoga practitioners do some severe damage in the form of microtears to their hamstrings in their attempts to stretch and increase the length of their hamstring muscles. 

Although flexibility and hamstring muscle length are worth working for, you don't want highly flexible hamstrings as they will inhibit your control over their range of motion and increase your risk of injury. On the other hand, you want a degree of flexibility to do leg stretching yoga while ensuring optimal knee, leg, and hip health. 

A healthy hamstring has muscle fibers that can expand and contract without tearing. Whether your hamstring muscles are short or long, you should do a concentric exercise called Hamstring Slides.

Hamstring Slides

There are many yoga poses for strengthening hamstrings, but this exercise is crucial for promoting your hamstring muscle health. 

• Start by placing your yoga mat on a slippery surface and lie down with your head, back, and bottom on the mat and your legs on the floor. With your heels as an anchor on the ground, pull your bottom towards your feet, utilizing only your hamstrings.
• Keep your knees parallel and pointing upwards as you pull your body to your feet. Straighten your legs when your bottom reaches your feet, and repeat this exercise until you are tired.
• If you struggle with this exercise, it's a sign that you need to strengthen your hamstrings. Hamstring flexibility without strength can lead to shortened hip flexors, muscle imbalances, and, as a result, a forward pelvic tilt and back pain. 

Yoga for Hamstrings

Several yoga poses to increase your hamstrings' range of motion and strength. Practicing these poses will increase your ability to carry out complex yoga poses for your hamstrings without risk of injury while keeping control over your hamstring muscles' range of motion. 

Uttanasana

If you have limited flexibility in your hamstring, this posture will stretch your lateral hamstring muscle, the biceps femoris. 

Stand with your feet hip-width apart. Put a slight bend on your knees and hinge from your hips to fold forward. You can place a block under your hands if you cannot touch the ground. Let your belly touch your thighs and stay there for at least five breaths. After that, try straightening your legs more as you fold forward while keeping your stomach on the thighs.

To strengthen the hamstrings, transfer the body weight to your right foot and pull your left heel back without leaving the ground as if you were trying to bend your left knee. That will contract your hamstrings, bringing in the strength part of it. Take a couple of breaths, then switch legs.

Upward Plank Pose

This pose aims to strengthen the hamstrings, glutes, calves, and back muscles. Start this posture by sitting in the staff pose with your upper body upright and your legs extended in front of you.

Place your palms about ten inches behind you with your fingers pointing towards your feet. 

Then, place the soles of your feet on the ground, and use your back-body muscles to raise your body from the floor into a reverse-incline plank position.

Use your hamstrings to lift your hips and push your thighs toward each other. Try to keep this pose as long as possible. 

Variation of the Reclining Hand-to-Big-Toe Pose

With this pose, you can determine the current length of your hamstring. Start by lying on the floor with one foot against a wall. Then, place a strap around the center of the sole of your foot, engage your core, and lift your leg by bringing your right hip into flexion. Try to keep both legs straight.

While you carry out this pose, your spine should be neutral, and your pelvis should not tilt or shift. As soon as you feel your hamstrings stretch, stop pulling your leg up with the strap and take deep breaths. Wait until the stretching sensation disappears before switching sides. (Miller, 2017)

Conclusion

Generally speaking, it's best to warm up your hamstrings before doing intensive stretches. You can warm up your hamstrings by walking and doing the above poses. If you want to improve your yoga practice but are limited by your hamstrings, focus on doing your hamstring slides to improve hamstring health and strength and increase hamstring length.

 
If you're suffering from a hamstring injury, strengthening is essential to increase blood flow and prevent muscle tearing in the future. Other postures you can include during asana sessions include the Warrior I, Warrior II, and bridge poses. As always, take care as you practice, and let yoga teachers at your yoga studio know you have an injury before taking their class. 

If you can, supplement your yoga practice with walking, running, and weight training to strengthen your hamstring muscles and increase blood flow through the muscle tissue. If you Can't go for a walk or a run, try some online courses or yoga videos with a strengthening focus.

When it comes to stretching, be patient. Please don't push it too far. A hamstring injury can be painful and debilitating. If you experience pain during poses and exercises, it may be a sign of microtears or muscle pulling.