Groin Strains – Why, How and After
Hip Adductor Strain (Groin Strain) – Detailed article
Hip adductor strain refers to a strain, tear or rupture of one or more musculotendinous components of the adductor muscle group within the inner compartment of the thigh.
The muscles consist of gracilis, longus, brevis and magnus, and obturator externus.1
The main action of the adductor group is inward movement of the thigh towards or across the other leg. It contributes a little to hip stabilisation.
The adductor group contributes significantly to sports involving kicking, and when fast, short bursts of acceleration in running such as in basketball, sprinting, dancing and swimming.2 The adductor group is important in horse riding to maintain balance and posture.
A number of risk factors have been proposed that predispose athletes to adductor injury: 6-8
- Participation in sports that involve repetitive or high intensity hip adduction increases the probability of injury. Added risk factors are:
- less sport-specific off-season training;
- increasing age;
- prior hip adductor injury;
- reduced strength; and
- reduced flexibility.
features of groin strain increase with injury severity. They include:
- localised redness;
- Swelling; and
- haematoma (deep bruising.)
Microscopic Features1. Disruption of musculotendinous architecture:
2. Acute inflammatory reaction:
Soft tissue injury results in vasodilatation, increased vascular permeability, inflammatory cell infiltration, activation and response.
3. Resolution and termination of inflammation:
4. Repair phase:
The inflammatory and repair phases overlap during the first week after injury. Once inflammation begins to subside, healing and repair can commence.
This involves the laying down of collagen and the beginning of regeneration of damaged muscle fibres. Pain subsides and range of motion improves. Premature initiation of exercise during the repair phase can initiate chronic muscle strain.
Maturation and remodelling phase:
Maturation and remodelling begins 2 to 3 weeks post injury. Return to sport usually begins in this phase with a slow progression to full activity via a structured rehabilitation program. Full muscular strength returns as activity is increased.
- Signs are redness, localised heat, swelling and point tenderness.
- Pain at the initiation of injury
- Point tenderness is used to isolate which adductor is involved
- Loss of function is dependent upon the severity of the injury and can range from no loss of range of movement (Grade 1) to complete loss of function (Grade 3).
Prognosis of adductor strain is dependent upon the grading of the injury:
- Grade 1 injury is the separation of muscle fibres resulting from damage to surrounding connective tissue. It may only require a few days of rest or reduced intensity activity.
- Grade 2 injury involves tearing of muscle fibres. AIt may require up to two weeks rest and rehabilitation.
- Grade 3 injury is complete rupture of one or more muscle fascicles or tendinous avulsion. It has a variable outcome and often requires surgical intervention.13
Management is guided by 5 core steps, summarised as PRICE:14
As with all exercise related soft tissue injuries, prevention is the best means of injury management.
A core goal with adduction injury prevention is to aim for adductor strength of least 80% of abduction strength. Sport specific strengthening and training is also an important aspect of injury avoidance.
Groin stretches can also help. stretch : Lie on your back and position the foot of your good leg flat against the wall so that your knee and hip are bent at a right angle. Cross the ankle of your problem leg over the opposite knee and press down on the knee of your problem leg until you feel a gentle stretch in your groin.15
Rest is important to reduce inflammation and limit the extent of the injury. A common cause of chronic adductor injury is premature return to activity.2
Ice applied to the site of injury is first line treatment for suspected and confirmed soft tissue injury to reduce inflammation for approximately 10 minutes. This should be repeated 3-4 times daily for up to a week after injury.13
Like ice, compression bandages and compression clothing can be used to reduce the extent of acute inflammation. Compression also improves blood circulation to aid recovery.2 A compression bandage or clothing should be used until full recovery from injury.13
Elevation of the adductors to the height of the heart assists blood flow and the reduction of inflammation related oedema of the surrounding tissue. 13
A grade 3 injury will most likely require surgical correction in order to restore function. This is especially the case following tendinous avulsion. Post operative recovery and rehabilitation will be a minimum of 6 months.13
Pharmacological treatment of hip adductor strain addresses the pain and associated inflammation of the injury. Control of inflammation can shorten the duration of injury and prevent progression to chronic strain. Analgesics in the form of paracetamol(eg Panadol) are effective for pain relief, whilst NSAIDs (oral and/or topical) target inflammation. COX-2 inhibitors may be prescribed as an alternative to NSAIDs.13