A hamstring strain, often called a pulled hamstring, occurs when one or more of the three muscles along the back of the thigh are overloaded and tear. These injuries range from a mild pull (Grade 1) to a partial tear (Grade 2), or a complete rupture (Grade 3). Since the hamstrings are involved in both knee bending and hip extension, they are vulnerable during high-speed movements like sprinting or sudden stretching. Due to the high rate of re-injury, a structured, progressive rehabilitation plan is the most effective path to recovery. This article provides a general framework, but anyone who suspects a strain should seek immediate professional medical advice for an accurate diagnosis and a personalized treatment plan.
Initial Management of the Acute Injury
The first 48 to 72 hours following a hamstring strain focus on reducing pain and managing swelling. Immediate care has evolved from the traditional RICE (Rest, Ice, Compression, Elevation) to the more modern POLICE principle, which emphasizes Protection and Optimal Loading. Protection involves temporarily avoiding activities that cause pain, which may mean using crutches if walking is difficult. Complete, prolonged rest is now discouraged because it can lead to stiffness and muscle weakening, delaying the overall recovery process.
Optimal Loading introduces gentle movement as soon as it can be tolerated without pain, promoting blood flow and tissue healing. Ice, Compression, and Elevation remain components of acute care, helping to control swelling and provide pain relief. Ice should be applied in repeated 10-to-15-minute intervals, using a barrier to protect the skin. A compression bandage helps minimize fluid buildup, and elevating the leg above the heart level assists with draining excess fluid.
Phase One Gentle Mobility and Isometric Strengthening
Once acute pain and swelling have subsided, typically within the first week, rehabilitation shifts into the active recovery phase. The initial goal is to gently restore pain-free range of motion without aggressively stretching the injured tissue, which could cause re-injury. Active range of motion exercises, such as gentle heel slides or active knee extensions while lying down, should be performed only to the point of light tension, not pain.
This phase also introduces isometric strengthening, which involves contracting the muscle without changing its length or moving the joint. Isometrics are beneficial because they allow tension to be applied to the muscle fibers, strengthening the healing scar tissue without risking a tear from movement. Simple examples include pushing the heel gently down into the floor or a bench in a slightly bent-knee position, holding the contraction for 10 to 30 seconds. This early, controlled loading restores the muscle’s capacity.
Phase Two Progressive Loading and Dynamic Exercise
Phase Two is the longest part of rehabilitation, focusing on rebuilding the muscle’s strength, power, and endurance. The key distinction from Phase One is the introduction of progressive resistance training, including both concentric (muscle shortening) and eccentric (muscle lengthening) contractions. Eccentric strength is particularly important because most hamstring injuries occur when the muscle is lengthening under tension, such as during the late swing phase of sprinting.
Training the hamstring eccentrically in a lengthened position has been shown to increase muscle fascicle length, a structural adaptation that helps the muscle absorb greater loads and reduces the risk of future strains. The Nordic Hamstring Curl is a highly effective eccentric exercise where an individual slowly resists falling forward from a kneeling position. For those unable to perform the full Nordic curl, exercises like the Single-Leg Romanian Deadlift (RDL) or glute-ham raises are excellent alternatives to load the hamstrings in a hip-hinge position.
These exercises should begin with low resistance and be performed slowly, focusing on the eccentric, or lowering, portion of the movement. For example, a two-up, one-down hamstring curl, where both legs lift the weight and only the injured leg slowly lowers it, emphasizes the lengthening contraction. Intensity must be gradually increased by adding weight, increasing the range of motion, or decreasing the tempo of the eccentric phase. The goal is to safely restore strength to within 10 to 20 percent of the uninjured leg before progressing to high-speed activity.
Return to Activity and Preventing Recurrence
The final phase of rehabilitation involves preparing the muscle for the high-speed and high-force demands of sport or full activity. Returning to activity too soon is the leading cause of hamstring re-injury. Objective criteria, rather than just the absence of pain, should guide the decision to return to play.
Before a full return, the individual must demonstrate a full, pain-free range of motion, and the injured leg’s strength should be near equal to the uninjured side. Assessment often involves measuring eccentric hamstring strength and flexibility using tests like the Active Knee Extension test. Rehabilitation must then incorporate a progressive series of sport-specific drills, including accelerations, decelerations, and high-speed running.
High-speed running is crucial because no amount of gym-based strength training can perfectly replicate the demands placed on the hamstring during sprinting. These functional drills should start at submaximal speeds and volumes, gradually increasing intensity over several weeks. Long-term prevention strategies, such as maintaining hamstring and lumbopelvic stability and continuing eccentric strengthening exercises like the Nordic Hamstring Curl two to three times per week, are necessary to condition the muscle and minimize the risk of a future strain.