Pacific Rim Orthopedic Surgeons

Hamstring Strain: Grade One Hamstring Injury

A hamstring strain is the lowest grade of a hamstring injury and is a very common injury, especially among athletes. While different grades of a hamstring injury partially relate to the severity of the pain experienced, a strain can still be fairly painful. Most treatments for hamstring strains are at-home methods, but the length of recovery can last several months.

What is a Grade One Hamstring Injury: Strain?

A hamstring strain occurs when one of the three muscles that make up the hamstring becomes overloaded, potentially leading to a tear or beginning to tear. It’s often caused by failing to warm up before exercising, weak glutes, and activities like running or jumping, sudden stopping and starting. These activities can overstretch the muscle fibers (strain) from unprepared muscles responding to excessive weight or movement suddenly.

Hamstring pain pulled muscle on back thigh painful red area.

Hamstring Anatomy

While the hamstring is referred to as a string, it’s a group of three skeletal muscles that are voluntary; a person has the ability to consciously control how they move and work. The three hamstring muscles are at the back of the thigh, beginning at the hip and inserting into the knee, with hamstring tendons attaching the muscles to bones in the pelvis, knee, and lower leg.

The hamstring muscles primarily allow for bending the knee joint, extending the hip joint, and rotating the hip joint, activated when walking, climbing stairs, doing squats, and many other leg movements. These muscles include:

Biceps femoris

The muscle closest to the outside of the body, allowing the knee to flex, extending the thigh at the hip, and rotating the lower leg.


The muscle closest to the middle of the body, allowing the knee joint to flex, extend the thigh at the hip, and rotate both the hip and lower leg.


This muscle is between the other two and functions the same as the semimembranosus.

Symptoms of a Strain

When a strain occurs in the hamstring, symptoms typically include:

  • Sudden pain or discomfort in the back of the thigh
  • Mild swelling or bruising
  • Muscle tightness and tenderness
  • Minimal loss of strength or function
  • Difficulty with activities that stretch or load the hamstring
If a person experiences any of these symptoms, it is important to stop performing the current activity. Attempt to keep weight off the affected leg and seek medical attention to ensure the strain doesn’t progress to a hamstring tear or other injury.

Strain Treatment Options

Hamstring strains, whether minor or moderate, usually heal on their own with no medical intervention. While it’s important to be diagnosed to ensure no greater injury has occurred, at-home care techniques can speed recovery along:

Resting the affected leg

Avoid putting weight on the leg as much as possible, perhaps using a crutch.

Ice the affected leg

A healthcare provider will instruct on the frequency and for how long to ice the leg, typically twenty to thirty minutes several times a day until the pain subsides.

Leg compression

An elastic bandage around the leg can help reduce swelling.

Keep the leg elevated

Use a pillow when sitting or lying down.

Use over-the-counter NSAIDs

Over-the-counter medications like Ibuprofen or Aleve can help reduce pain and swelling.

Methods to Prevent Injury to the Hamstring

To prevent further strains or reduce the risk of having a first one, it’s important to take specific precautions: