Hamstring Strains in Athletes: Causes, Diagnosis, Treatment and Return to Play
Kathy Ryan-Ceisel, PT
MHS | Algonquin Sports PT
Overhead Throwing Expert-Athletic Edge and Wellness Edge
Hamstring strains are one of the most common injuries in athletes—particularly in sports that require sprinting, acceleration, deceleration, jumping, kicking, cutting and rapid changes of direction.
They are also one of the most frustrating injuries for athletes because feeling better does not necessarily mean the hamstring is ready for full-speed sport.
An athlete may be able to jog, stretch and perform basic strengthening exercises without pain but still be unable to tolerate the high-speed demands of competition. This is one reason hamstring injuries have a high recurrence rate. Research suggests that approximately one-third of hamstring strains recur, with the risk of reinjury particularly high soon after returning to sport.
At Edge 360 Wellness, hamstring rehabilitation focuses not only on getting rid of pain, but on restoring strength, mobility, neuromuscular control, running mechanics and the ability to tolerate the specific demands of the athlete's sport.
What Is a Hamstring Strain?
The hamstring muscle group consists of three primary muscles:
Biceps femoris
Semitendinosus
Semimembranosus
These muscles cross both the hip and knee and are responsible for hip extension and knee flexion. They also play an important role in controlling the pelvis, decelerating the leg and controlling the lower extremity during running.
A hamstring strain occurs when the muscle or musculotendinous unit is exposed to forces that exceed its capacity.
This commonly occurs when the hamstring is required to produce high force while simultaneously being lengthened—particularly during high-speed running.
The biceps femoris long head is the most frequently injured hamstring muscle in many athletic populations. In professional football, MRI studies have found that the biceps femoris accounts for the majority of hamstring injuries.
Who Is Most Likely to Suffer a Hamstring Strain?
Hamstring strains can occur in athletes of almost any age, but they are particularly common in athletes participating in high-speed sports.
Common sports include:
Football
Soccer
Track and field
Baseball
Softball
Basketball
Rugby
Tennis
Lacrosse
Hockey
Sprinting
Dance
Sports that combine maximum-speed running with rapid acceleration and deceleration place particularly high demands on the hamstring.
For example, in football, defensive backs and wide receivers are frequently affected because their positions require repeated sprinting, acceleration and changes of direction.
In baseball and softball, hamstring injuries can occur during:
Sprinting out of the batter's box
Stealing bases
Chasing down fly balls
Running through the infield
Sudden acceleration or deceleration
Sliding
Defensive movements
When During the Season Do Hamstring Injuries Happen?
Hamstring injuries can occur at any point during a season, but injury patterns are not necessarily evenly distributed throughout the year. Research has demonstrated increased hamstring injury rates during preseason and early periods of competition, when athletes may suddenly increase sprinting and high-intensity workloads. Hamstring injuries are also more common during competition than routine training in many sports.
This makes the transition into a new season particularly important.
An athlete may have spent several weeks or months participating in relatively low-intensity training and then suddenly be expected to perform repeated maximal sprints, cutting drills and competitive movements. The problem isn't necessarily that the athlete is "out of shape." The problem may be that the hamstring has not been adequately exposed to the specific intensity and speed required for competition.
Common Causes of Hamstring Strains
Hamstring injuries are rarely caused by one isolated factor.
They often occur when several factors combine.
1. High-Speed Sprinting
Maximum or near-maximum sprinting places enormous demands on the hamstrings. During late swing phase of sprinting, the hamstring muscles are lengthening while producing high levels of force to prepare the leg for ground contact. This makes high-speed running one of the most important mechanisms of hamstring injury.
2. Sudden Increase in Training Load
Rapidly increasing:
Sprint volume
Running distance
Practice intensity
Games
Cutting
Conditioning
Tournament participation
can exceed the athlete's current tissue capacity.
3. Previous Hamstring Injury
A previous hamstring injury is one of the most important risk factors for another hamstring injury. This is why simply getting an athlete "pain-free" is not enough.
The goal should be to restore the athlete's capacity to tolerate the demands that caused the injury in the first place.
4. Strength Deficits
Weakness of the hamstrings, glutes or surrounding musculature can contribute to poor force production and force distribution. Eccentric hamstring strength is particularly important because the hamstrings must absorb and produce force while lengthening during high-speed running.
5. Inadequate Sprint Preparation
An athlete who has not sprinted at high speeds should not be expected to immediately tolerate repeated maximal sprints. High-speed running must be progressively reintroduced.
6. Fatigue
Fatigue can alter running mechanics and reduce the athlete's ability to produce and absorb force effectively. This becomes particularly important late in practices, games and tournaments.
7. Poor Lumbopelvic and Hip Control
The hamstrings don't work independently. The pelvis, trunk, hip, knee and ankle all influence hamstring loading. A comprehensive rehabilitation program therefore needs to address the entire kinetic chain.
8. Inadequate Warm-Up
Going directly into maximal sprinting without progressively preparing the muscles and nervous system may increase injury risk.
A dynamic warm-up is preferable to simply holding static stretches before explosive activity. Research has demonstrated improvements in sprint, strength and explosive performance following appropriate dynamic warm-up strategies. (PubMed)
9. Cold Temperatures
Cold conditions can make adequate preparation more difficult and may contribute to stiffness and reduced readiness for explosive activity.
The solution is not simply “stretch more.”The athlete should increase movement and progressively build intensity before maximal effort.
The risk is especially relevant in:
Early spring baseball and softball
Cold-weather soccer
Football
Track and field
Outdoor lacrosse
Early-season practices
Athletes standing around or sitting on the bench for extended periods before competition
Where Does a Hamstring Strain Usually Occur?
The injury may occur in the muscle belly, musculotendinous junction or tendon.
The proximal hamstring region near the buttock can also be injured, although proximal hamstring tendinopathy and proximal hamstring tendon avulsions are different conditions from a typical acute muscle strain.
Location matters because the location, tissue involved and severity of the injury can influence prognosis. MRI research in professional football has shown that injuries involving multiple muscles, greater tissue involvement, retraction and certain locations are associated with longer time away from sport.
What Does a Hamstring Strain Feel Like?
Athletes often describe:
Sudden sharp pain in the back of the thigh
A pulling or tearing sensation
Pain while sprinting
Pain with acceleration
Pain when stretching the hamstring
Pain with resisted knee flexion or hip extension
Localized tenderness
Weakness
Tightness or stiffness
Difficulty running at full speed
Some athletes describe feeling like they were "kicked" in the back of the leg.
A mild strain may allow an athlete to continue playing, while a more significant injury can immediately stop activity.
How Is a Hamstring Strain Diagnosed?
Diagnosis begins with a detailed history and physical examination.
A sports physical therapist or sports medicine physician may evaluate:
Mechanism of injury
Location of pain
Palpation
Active and passive range of motion
Pain with hamstring lengthening
Resisted knee flexion
Hip extension strength
Eccentric hamstring strength
Functional movements
Running mechanics
Sprinting ability
The combination of sudden posterior thigh pain, tenderness, pain with hamstring contraction or lengthening and loss of function is characteristic of an acute hamstring strain.
Is an MRI Necessary?
Not every hamstring strain requires an MRI.
Many hamstring injuries can be diagnosed clinically.
However, MRI can be useful when:
The diagnosis is uncertain
The injury appears significant
There is concern for a high-grade tear
There is significant weakness
There is concern for tendon involvement
There is suspected proximal hamstring avulsion
The athlete is not progressing as expected
The clinician needs additional information regarding the extent and location of the injury
MRI can help characterize injury severity and may provide useful prognostic information. However, MRI should not be used by itself to determine when an athlete is ready to return to sport. Clinical function and performance are extremely important.
What Are the Grades of Hamstring Strains?
Hamstring injuries are commonly described as:
Grade I – Mild
A small amount of tissue involvement.
Symptoms may include:
Mild pain
Minimal strength loss
Mild tenderness
Little functional limitation
Grade II – Moderate
A partial muscle injury with more significant pain and functional impairment.
The athlete may have:
Significant tenderness
Weakness
Pain with walking or running
Reduced range of motion
Difficulty accelerating or sprinting
Grade III – Severe
A severe or complete muscle/tendon disruption.
These injuries may involve:
Significant weakness
Difficulty walking
Extensive bruising or swelling
Major loss of function
Possible tendon retraction
A suspected complete proximal hamstring avulsion requires medical evaluation and may require surgical consultation.
Treatment for Hamstring Strains
Treatment should be individualized based on the severity, location and functional demands of the athlete.
Early Phase
The initial goals are to:
Protect the injured tissue
Control pain
Minimize excessive irritation
Maintain appropriate movement
Begin progressive loading when appropriate
Complete rest for an extended period is generally not the goal.
Instead, rehabilitation should transition toward progressive loading as soon as the tissue can tolerate it.
Physical Therapy
Physical therapy is one of the most important components of hamstring rehabilitation.
A comprehensive program may include:
Early strengthening
Isometric hamstring contractions
Bridges
Heel digs
Controlled hip extension
Low-load hamstring strengthening
Progressive strengthening
Hamstring curls
Romanian deadlifts
Single-leg deadlifts
Hip extension exercises
Slider curls
Nordic hamstring progressions
Eccentric strengthening
Eccentric loading is particularly important because the hamstrings must tolerate high forces while lengthening during sprinting. Rehabilitation research supports incorporating eccentric hamstring and hip-extensor strengthening into rehabilitation such as nordics. Nordic exercises can be a valuable tool—but they should be part of a comprehensive injury-prevention and performance program, not the entire program.
Neuromuscular training
The athlete also needs to regain control of:
Pelvis
Hip
Knee
Trunk
Single-leg mechanics
Running Progression
One of the most important parts of hamstring rehabilitation is progressive running exposure.
An athlete cannot be considered fully rehabilitated simply because they can:
Walk without pain
Jog
Perform strengthening exercises
Stretch without discomfort
They must eventually demonstrate the ability to tolerate progressively faster running.
The current international consensus emphasizes progressing athletes toward full-speed sprinting before unrestricted return to sport because high-speed running represents a major demand on the hamstring.
A typical progression may include:
Phase 1 Walking → light jogging
Phase 2 Jogging → running
Phase 3 Running → acceleration
Phase 4 Acceleration → high-speed running
Phase 5 Higher-speed running → near-maximal sprinting
Phase 6 Deceleration work
Phase 7 Sport-specific sprinting, cutting, jumping and reactive movements
The exact progression should be individualized.
Phase 8 Return to practice
Return 9 Return to competition
How Long Does a Hamstring Strain Take to Heal?
There is no single timeline.
A mild injury may allow an athlete to return relatively quickly, while a significant injury can require several weeks or longer.
MRI studies have demonstrated substantially different recovery times depending on injury grade and characteristics. For that reason, "two weeks" or "four weeks" should not automatically be used as a return-to-play deadline.
The better question is:
Is the athlete ready to tolerate the demands of their sport?
Return to Play: What Should Be Tested?
Returning an athlete simply because they are pain-free is not enough.
Before unrestricted return, the athlete should demonstrate:
Full or Near-Full Range of Motion
The athlete should have restored hamstring mobility without pain or significant asymmetry.
Strength
Hamstring strength should be evaluated objectively whenever possible.
Testing may include:
Hand-held dynamometry
Isokinetic testing
Single-leg strength testing
Eccentric hamstring testing
Functional strength assessments
Sprinting
The athlete should progressively demonstrate the ability to run at or near the speeds required by their sport.
Acceleration and Deceleration
The athlete should tolerate repeated acceleration and deceleration without pain, apprehension or compensatory movement.
Cutting and Change of Direction
For sports requiring multidirectional movement, rehabilitation must progress beyond straight-line running.
Jumping and Landing
Jumping, hopping and landing should be assessed when relevant to the athlete's sport.
Sport-Specific Drills
A soccer player, football wide receiver, baseball player and basketball athlete do not have identical hamstring demands.
Return-to-play testing should reflect the athlete's actual sport.
Fatigue Testing
This is often overlooked.
An athlete may perform perfectly when fresh but demonstrate weakness, altered mechanics or pain after repeated sprinting.
The goal is not simply to test whether the athlete can perform one good sprint.
The goal is to determine whether they can repeatedly tolerate the demands of competition.
Why Do Hamstrings Keep Getting Reinjured?
This is one of the biggest problems with hamstring injuries. An athlete may feel normal during daily activities long before the hamstring has regained its previous capacity.
Research indicates that recurrence is particularly common shortly after returning to sport, emphasizing the importance of completing a comprehensive rehabilitation program rather than stopping treatment when symptoms disappear.
Common reasons for recurrence include:
Returning too quickly
Inadequate eccentric strength
Inadequate sprint exposure
Persistent strength deficits
Poor lumbopelvic control
Incomplete rehabilitation
Sudden increase in workload
Failure to address the original cause of injury
Preventing Hamstring Injuries
Prevention should begin before the athlete gets hurt.
Important components include:
Progressive sprint training
Eccentric hamstring strengthening
Hip and glute strengthening
Single-leg strength
Core and pelvic control
Mobility work when appropriate
Appropriate workload management
Adequate recovery
Sport-specific conditioning
Exercise-based injury-prevention programs have demonstrated meaningful reductions in hamstring injury rates, particularly programs incorporating eccentric strengthening. (PubMed)
A structured warm-up is also important. Research on programs such as FIFA 11+ demonstrates that comprehensive dynamic warm-up and neuromuscular programs can reduce injury risk while improving physical performance. (PubMed)
A well-designed program should prepare the athlete for the actual demands of their sport.
The Bottom Line
A hamstring strain isn't simply a "pulled muscle."
It is an injury that can affect an athlete's ability to sprint, accelerate, decelerate, cut and perform at full speed. The most successful rehabilitation programs don't stop when the athlete becomes pain-free.
They progressively restore:
Mobility → Strength → Eccentric capacity → Running → Sprinting → Sport-specific performance → Full competition
At Athletic Edge and Wellness, our goal is to help athletes not only recover from hamstring injuries but return with the strength, speed and confidence necessary to perform at their previous level. Call us at 224-505-3343 today for an appointment.
Don't let "feeling better" be the only measure of recovery. Make sure your hamstring is ready for what your sport demands.
Comments