I sprained a hamstring in my knee and the doctor says i need to strengten it how do that?

Here are some exercises that can help you strengthen your hamstring:

- Straight leg raise: Lie on your back with your knees bent and your feet flat on the floor. Slowly straighten one leg and raise it until it is parallel to the floor. Hold for a few seconds and then lower it slowly. Repeat with the other leg. Do this exercise 10-15 times on each leg.

- Hamstring curls: Lie on your back with your knees bent and your feet flat on the floor. Place a towel or rolled up towel under your heels. Slowly bend your knees until your thighs are perpendicular to the floor. Hold for a few seconds and then straighten your legs. Repeat this exercise 10-15 times.

- Prone leg raises: Lie on your stomach with your legs straight and your feet together. Slowly raise one leg until it is about 6 inches off the ground. Hold for a few seconds and then lower it. Repeat with the other leg. Do this exercise 10-15 times on each leg.

- Step-ups: Stand facing a step that is about knee-height. Step up onto the step with one leg and raise the other knee until your thigh is parallel to the ground. Hold for a few seconds and then step back down. Repeat this exercise 10-15 times on each leg.

- Wall sits: Stand with your back against a wall and your feet shoulder-width apart. Slowly slide down the wall until your knees are bent at a 90-degree angle and your thighs are parallel to the floor. Hold this position for as long as you can, up to 30 seconds. Repeat this exercise 2-3 times.

In addition to these exercises, you can also do other things to help strengthen your hamstring, such as:

Massage: Massaging your hamstring can help to improve blood flow and reduce pain.

Heat: Applying heat to your hamstring can help to relax the muscles and reduce pain.

Ice: Applying ice to your hamstring can help to reduce inflammation and pain.

Stretching: Stretching your hamstring can help to improve flexibility and reduce pain.

Be sure to talk to your doctor before starting any exercise program, especially if you have a medical condition.