An adductor strain, commonly referred to as a groin strain, is an injury to one or more of the muscles on the inside of the thigh. These muscles play a critical role in bringing the leg inwards towards the body and in controlling the hip during running, kicking, and change of direction activities. Adductor strains are particularly common in sports such as soccer, hockey, Australian football, and rugby.
The adductor muscle group includes the adductor longus, adductor brevis, adductor magnus, and gracilis. All originate from the pubic bone, with gracilis being the only muscle that crosses the knee joint. Physiotherapy for adductor strains focuses on restoring strength, control, and load tolerance to allow a safe return to sport and reduce the risk of recurrence.
Key Facts
- Adductor strains are one of the most common causes of groin pain in field-based and kicking sports.
- Most adductor strains occur during sprinting, kicking, or rapid changes of direction.
- Inadequate rehabilitation significantly increases the risk of recurrent groin injuries.
Risk Factors
- Participation in kicking or field-based sports
- Previous groin or hip injury
- Poor adductor strength or limb asymmetry
Symptoms
- Sudden onset of pain during running, sprinting, or kicking
- Pain along the inner thigh or groin region
- Pain when squeezing the legs together
- Pain with change of direction or acceleration
- Reduced strength or confidence using the affected leg
Aggravating Factors
- Sprinting or accelerating
- Kicking or cross-body movements
- Sudden changes of direction
Causes
Adductor strains typically occur when the muscle is exposed to a force greater than it can tolerate, often during rapid lengthening contractions such as sprinting, kicking, or cutting movements. This can lead to microscopic or more significant tearing of muscle fibres.
Risk is increased when there is muscle weakness, fatigue, poor load management, or strength imbalances between the adductors and surrounding muscle groups. Inadequate warm-up and rapid increases in training load are also common contributing factors.
How Is It Diagnosed?
Adductor strains are primarily diagnosed through a detailed clinical assessment by a physiotherapist. This includes a history of the injury mechanism, palpation of the adductor muscles, and strength testing such as resisted adduction.
Imaging is not always required but may be used in more severe cases or when symptoms fail to improve as expected, to confirm the extent of muscle damage or exclude other causes of groin pain.
Investigations & Imaging
- Ultrasound
- Used to identify muscle fibre disruption and grade the severity of an adductor strain
- MRI
- Provides detailed assessment of muscle injury and helps exclude other groin pathologies
Grading / Classification
- Grade 1 (Mild)
- Less than 10% of muscle fibres torn with minimal strength or range loss
- Grade 2 (Moderate)
- 10 to 50% of muscle fibres torn with moderate pain and functional limitation. Usually, unable to continue playing, but able to walk.
- Grade 3 (Severe)
- Greater than 50% muscle fibre tear with significant loss of function and inability to continue activity. Often, unable to weight bear.
Physiotherapy Management
Physiotherapy management of adductor strains is based on injury severity, stage of healing, and sport-specific demands. The goals are to restore strength, improve load tolerance, and safely return the athlete to full participation.
Exercise
Strengthening begins early in rehabilitation, often starting with isometric adductor exercises to promote muscle activation and pain reduction without excessive strain. As symptoms improve, exercises progress to include concentric and eccentric strengthening to prepare the muscle for sport-specific demands.
Stretching can be beneficial to improve muscle length, and prevent risk of future tears. However stretching should be avoided in the early stages, particularly for more severe tears, as it can further separate torn muscle fibres and slow down healing early on.
Structured rehabilitation programs, such as the Copenhagen protocol, may also be implemented by your physiotherapist.
Activity Modification
Activity modification is essential in the early stages. High-speed running, kicking, and cutting movements are temporarily reduced, with gradual reintroduction guided by pain and functional testing.
Manual Therapy
Manual therapy techniques such as soft tissue release may be introduced after the acute inflammatory phase to improve circulation, reduce muscle tone, and support healing. Direct treatment over the tear site is avoided early on.
Clinicians may also treat surrounding areas, which can contributed to altered biomechanics. Judicious treatment may alter the risk of injury or re-injury.
Dry Needling
Dry needling may be used to reduce muscle spasm in surrounding tissues, with care taken to avoid the injured fibres during early healing.
Heat & Ice
Ice may be used in the early stages to manage pain and swelling, with heat introduced later to assist muscle relaxation.
Education
Education around injury grading, healing timelines, and load progression is essential to reduce fear and prevent premature return to sport.
Other
Rehabilitation also addresses control and stability of the pelvis, hips, and lower limbs to correct strength imbalances and reduce re-injury risk.
Other Treatments
Other management strategies may include short-term use of compression, crutches in severe cases, and gradual return-to-running and sport-specific programs.
Surgery
Surgery is rarely required for adductor strains and is reserved for complete ruptures or cases that fail to improve with comprehensive rehabilitation.
Prognosis & Return to Activity
Most adductor strains recover well with appropriate physiotherapy. Return to sport timelines range from 0 to 2 weeks for mild injuries, 2 to 6 weeks for moderate strains, and up to 12 weeks or longer for severe tears.
Complications
- Recurrent groin strains
- Chronic groin pain if inadequately rehabilitated
Preventing Recurrence
- Maintain adductor strength and symmetry
- Progress training loads gradually
- Complete full physiotherapy rehabilitation before returning to sport
When to See a Physio
- Sudden groin pain during sport
- Pain that persists beyond a few days
- Recurrent groin injuries affecting performance