Adductor muscle strain

Findings

The onset may be acute or chronic. There is local tenderness over the adductor longus origin, or the musculotendineus junction, about 6cm distal to the origin. If the adductor magnus is involved then tenderness may extend along the inferior pubic ramus to the ischial tuberosity. This lesion does not often present with lower abdominal pain. Resisted isometric testing at the inner and outer range of the adductor muscles is painful. Resisted adductors are painful with the hip flexed.

Cause

Chronic overuse of the adductor longus or magnus, which occurs with side steps, a side foot tackle, kicking, twisting, turning movements or a slide into abduction. If the force is high enough, or if the adductor contraction is blocked, the onset may be acute. An entheseal spur may form on the femur – the horse rider’s spur.

Resisted adductor pain without local, palpable tenderness is not likely to be caused by the adductor muscle itself.

These are usually not required, but an adductor enthesopathy may display a positive bone scan and specific MRI views can display localized muscle inflammation and bony oedema. Occasionally myositis ossificans can occur, which is best seen on X-ray or ultrasound.

Treatment

a)      electrotherapeutic modalities to settle inflammation

b)      local hydrocortisone to settle inflammation

c)      massage techniques, such as deep and cross friction, to reduce and realign scar tissue

d)     adductor stretches to limit scar tissue contraction

e)      isometrics to the adductors to help organize fibrocytes and maintain strength

f)       cross- train for fitness and start leg swinging movements, in and out abduction

g)      when fit to run, add the Achilles ladder through to sprints

h)      cross-over side steps and figure-of-eight movements, start the kicking ladder

i)        rarely, surgical debridement or tenotomy

Sports

a)      Acute injuries occur when side stepping, stretching for a tackle, or when a kick is blocked. Chronic injury often ensues but can come from recurrent twisting and stretching

b)      In track and field, block starts and acceleration utilize the adductors, and if the psoas is weak – limiting the drive from hip flexion – then the adductors are required to work harder. Strengthening the psoas will thus help.

This is a lesion that is often seen in chronic phase. A steroid placed at the adductor longus origin, accompanied by immediate rehabilitation, often settles this lesion at two weeks. Then running and side steps rehabilitation can be added. Sometimes, the injection helps differentiate the adductor lesion from the conjoined tendon injury and traumatic osteitis pubis symphisis, as the adductor lesion improves whilst the others are not affected.

"Concise guide to sports injuries, 2^nd edition",Churchill Livingstone, Malcolm T.F. Read,  foreword by Bryan English