SUMMARY OF HAMSTRING STRAIN
A hamstring strain is a frequent injury within the posterior compartment of the thigh; it is a common sport-related injury that mostly occurs in athletic activities that have high demands on sprinting,. The hamstring strain is a relatively wide classification of a condition that can range from a few torn muscle fibers or a partial muscle tear to a more severe, complete tear of the tendon or muscle fibers. Individuals commonly present with minimal to severe pain, difficulty with walking or running, substantial decrease in strength and flexibility. Hamstring strain rehabilitation is challenging due to slow healing times, persistent symptoms, and the hamstring's high re-injury rate. The primary objective for the rehabilitation program is to return the individual to their previous level of activity with the smallest risk of re-injury by restoring strength, endurance and flexibility.
GUIDE TO PHYSICAL THERAPY PRACTICE 
- Practice Pattern 4D: Impaired joint mobility, motor function, muscle performance and range of motion associated with connective tissue dysfunction
- Pattern 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Localized Inflammation
The guide suggests the following physical therapy interventions:
- Aerobic capacity/endurance conditioning or reconditioning
- Balance, coordination, and agility training
- Body mechanics and postural stabilization
- Flexibility exercises
- Gait and locomotion training
- Strength, power, and endurance training for head, neck, limb, pelvic-floor, trunk, and ventilatory muscles
According to the guide, Anticipated goals and expected outcomes may include:
- Joint swelling, inflammation, or restriction is reduced.
- Decreased pain
- Soft tissue swelling, inflammation, or restriction is reduced.
- Aerobic capacity is increased.
- Balance is improved.
- Endurance is increased.
- Energy expenditure per unit of work is decreased.
- Gait, locomotion, and balance are improved.
- Integumentary integrity is improved.
- Joint integrity and mobility are improved.
- Motor function (motor control and motor learning) is improved.
- Muscle performance (strength, power, and endurance) is increased.
- Postural control is improved.
- Quality and quantity of movement between and across body segments are improved.
- Range of motion is improved.
- Ability to perform physical actions, tasks, or activities related to self-care, home management, work (job/school/play), community, and leisure is improved.
- Risk factors are reduced.
- Risk of recurrence of condition is reduced.
Manual Therapy interventions suggested in the guide may include:
- Massage such as connective tissue massage and therapeutic massage
- Mobilization of soft tissue
- Passive range of motion
Procedural Interventions/Electrotherapeutic Modalities suggested in the guide may include:
- Electrotherapeutic delivery of medications (iontophoresis)
- Electrical stimulation (neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS))
Before starting any rehabilitation program, compression, elevation, rest and immobilization is essential in the acute phase of injury. The grade of injury determines the length of time for immobilization. Extended immobilization can cause atrophy, therefore immobilization should not be longer than 1 week even for the most severe hamstring strain.
Compression wraps are helpful in the early treatment of hamstring injury to minimize intramuscular bleeding and control the inflammatory response.
REHABILITATION: PHASE 1
The primary goal of phase one is to reduce pain and edema, and to prevent scar formation. In this phase, the athlete should avoid excessive stretching of the injured hamstring, and ice should be applied two to three times per day. Phase one therapeutic exercises begin with low-intensity, painless exercises involving the entire lower extremity and lumbopelvic region.
▪ Cryotherapy may include ice packs, ice massage, cold gel packs, Cryocuff, Game Ready
▪ Cryotherapy is effective for the initial treatment of hamstring strain for pain reduction, reduced inflammation and injury recovery.
▪ Cryotherapy focuses on icing the area often and after exercises to help decrease possible associated pain and inflammation.
▪ Non-steroidal anti-inflammatory medication (NSAID) commonly accompanies a multimodal approach to hamstring management. Its use is not recommended in an evidence-based practice for hamstring injuries.
▪ NSAID used for shorter periods can help to reduce tissue soreness and allow earlier progression from rest to early rehabilitation by minimizing inflammatory-mediated damage to healthy tissue but may be detrimental to tissue healing if used for longer period of time.
REHABILITATION: PHASE 2
The primary goal of phase two is to increase the intensity of range of motion exercises and begin eccentric movement of the hamstring to increase strength. In this phase, the athlete should avoid end range lengthening if weakness continues, and ice should be applied after exercises.
REHABILITATION: PHASE 3
The objective of phase three is to ready the athlete for functional return to their previous level of participation in the sport. This phase introduces functional sport-specific movements, full unrestricted range of motion, and speeds of eccentric hamstring strengthening at end range of motion. Trunk stabilization and postural control are also incorporated in this phase.
Example Rehabilitation Program
Below is an example of a rehabilitation program according to Heiderscheit et al.
Phase 1: Therapeutic Exercise (performed daily):
- Stationary bike × 10 min
- Side step × 10 m, 3 × 1 min, low to moderate intensity, pain-free speed and stride
- Grapevine × 10 m, 3 × 1 min, low to moderate intensity, pain-free speed and stride
- Fast feet stepping in place, 2 × 1 min
- Prone body bridge, 5 × 10 s
- Side body bridge, 5 × 10 s
- Supine bent knee bridge, 10 × 5 s
- Single limb balance progressing from eyes open to closed, 4 × 20 s
Phase 2: Therapeutic Exercise (performed 5-7 d/wk):
- Stationary bike × 10 min
- Side shuffle × 10 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Grapevine jog × 10 m, 3 × l min, moderate to high intensity, pain-free speed and stride
- Boxer shuffle × 10 m, 2 × 1 min, low to moderate intensity, pain-free speed and stride
- Rotating body bridge, 5 s hold each side, 2 × 10 reps
- Supine bent knee bridge with walk outs, 3 × 10 reps
- Single limb balance windmill touches without weight, 4 × 8 reps per arm each limb
- Lunge walk with trunk rotation, opposite hand-toe touch and T lift, 2 × 10 steps per limb
- Single limb balance with forward trunk lean and opposite hip extension, 5 × 10 s per limb
Phase 3:Therapeutic Exercise (performed 4-5 d/wk):
- Stationary bike × 10 min
- Side shuffle × 30 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Grapevine jog × 30 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Boxer shuffle × 10 m, 2 × 1 min, moderate to high intensity, pain-free speed and stride
- A and B skips, starting at low knee height and progressively increasing, pain-free
- a. A skip is a hop-step forward movement that alternates from leg to leg and couples with arm opposition (similar to running). During the hop, the opposite knee is lifted in a flexed position and then the knee and hip extend together to make the next step.
- b. B skip is a progression of the A skip, however the opposite knee extends prior to the hip extending re-creating the terminal swing phase of running. The leg is then pulled backward in a pawing type action. The other components remain the same as the A skip.
- Forward-backward accelerations, 3 × 1 min, start at 5 m, progress to 10 m then 20 m
- Rotating body bridge with dumbbells, 5 s hold each side, 2 × 10 reps
- Supine single limb chair-bridge, 3 × 15 reps, slow to fast speed
- Single limb balance windmill touches with dumbbells, 4 × 8 reps per arm each leg
- Lunge walk with trunk rotation, opposite hand dumbbell toe touch and T-lift, 2 × 10 steps per limb
- Sport-specific drills that incorporate postural control and progressive speed
- Evidence to support electrophysical therapies is lacking and no hamstring-specific research exists, despite their well established use within physical therapy practice.
- Ultrasound is the most widely used therapeutic agent to enhance soft tissue healing but research has found it to be no more clinically effective than placebo. Evidence is lacking to support or refute the use of ultrasound as a therapeutic agent.
- Ultrasound is widely recommended for treatment of muscle injuries; however, its effectiveness is not definite. It appears that the high-frequency waves works to alleviate pain and augment the initial stage of muscle regeneration.
- The clinical effectiveness of transcutaneous electrical nerve stimulation (TENS) is controversial; some studies support and others refute its clinical effectiveness for pain relief.
Most importantly with the athletic patient population, hamstring strains are common and have a high recurrence rate, therefore, avoid early return to sports if full range of motion, strength, and functional abilities are not performed without complaints of pain or stiffness.