Hamstring pull symptoms can differ depending on the severity of your injury. With a mild hamstring strain you may only notice tightness in the hamstring muscles, however, a more serious tear or avulsion will cause weakness and severe pain in the posterior thigh. Common symptoms of hamstring pulls include:

Upper Leg Pain

sharp pain or twinges may be felt along the length of your hamstring or at a specific point on the back of your thigh. You may experience tenderness and/or muscle spasms in your hamstring muscle during active and resistive movements. Pain often increases when pressure is applied to the injured hamstring muscles.

It is possible to experience only mild pain when walking even if a tear in the muscle occurs, however, pain will increase if strenuous exercise is attempted. An avulsion, or complete tear causes extreme pain, even during rest. The torn tissue may bunch in the back of the thigh causing even more pain when the leg is bent.

If you have a chronic injury, you may feel more of a dull ache that lasts for long periods of time. Pain can be experienced while sitting or walking up or down stairs/hills.

Popping Noise

popping or snapping sensation at the back of your thigh can often be heard and felt when your hamstring muscles are tearing. This often happens with a large force of hip flexion when your knee is extended (straightened) and may cause you to fall to the ground.

Decreased Flexibility

You may experience stiffness or decreased range of motion (ROM) as a result of a pulled hamstring muscle. The tightness at the back of your thigh will make it difficult to flex your knee or straighten your leg. Your gait may be affected, or you may limp when you walk if the stiffness causes discomfort.

Muscle spasm may also occur in the injured hamstring. Injury can make the muscle and/or nerves behave abnormally and improper contraction signals may be sent to the brain causing the muscle to spasm.

Swelling and Bruising

Swelling in your hamstring muscles is a result of your tissues becoming inflamed; this normally occurs with a more serious hamstring strain. Warmth and redness may accompany swelling in severe cases. You may also feel a gap, dent or bulge in your muscle that is not normally present.

Occasionally, bruising (hamstring contusion) anddiscoloration over your hamstring muscle may appear immediately or after a few days with severe hamstring strains.

Weakness

Weakness or complete loss of function of your hamstring muscle can also be experienced as a result of a pulled hamstring. This along with your other symptoms may make it difficult for you to walk or run and can result in you walking with a limp.

With an avulsion, or rupture, you will experience difficulties walking without assistance, a cane, or crutches. You could even feel a gap in your muscle with a complete tear.