Pulled muscle in the leg behind the knee: what to know

A muscle strain is an overstretch or small tear in muscle fibres. Behind the knee, the lower hamstring muscles or upper calf muscles may be involved. Pain can feel sore, tight, or sharp when you straighten the knee, climb stairs, or push off with the foot. Bruising, swelling, weakness, or a sudden snapping sensation can suggest a more significant injury. Calf pain has other possible causes, so one symptom alone cannot identify the problem.

For the first day or two, reduce running, jumping, deep squats, and any movement that clearly increases pain. Keep the leg moving gently within a comfortable range rather than holding the knee rigid. A wrapped cold pack may ease soreness for short periods; protect the skin and stop if it aggravates symptoms. As walking becomes easier, add gentle strengthening and return to sport in stages. A physiotherapist can check hamstring and calf strength and tailor exercises.

Arrange an assessment if you cannot bear weight, the knee gives way, swelling or bruising is marked, or pain is not settling. Seek urgent medical help for a swollen, hot, or unusually tender calf, sudden breathlessness, chest pain, or faintness. These features need prompt evaluation because they may not be explained by a simple strain.

Ask which muscle appears affected, whether you need an examination or imaging, which exercises are suitable now, and what signs should delay your return to running or sport.