Although the quadriceps and hamstring muscles mainly move the knee joint, the hamstring group arise above the hip, too, and play a small part in the movement of that joint. Other tissues also incorporate the pelvis as well as the upper leg, with the result that pelvic and upper leg injuries may sometimes be indistinguishable and may often become confused. By virtue of their anatomy, hip joints allow a wide range of movement, not only forwards and backwards, outwards and inwards, but also rotational, and each of these movements requires appropriately placed muscle contractions. Some muscles even perform two functions, depending on the position of the hip. The function of the adductor muscles is to pull the thighs together and rotate the upper leg inwards, as well as stabilising the hip.
These muscles may be torn at their origin from the pelvis or in their bulk on the inside of the thigh.
In an acute tear there is sudden pain over these areas, which probably occurred as your foot slipped sideways or outwards, as when crossing a steeplechase hurdle. Because the muscles stabilise the hip, continued running will be painful.
There may be a tender swelling where the muscle was injured, and any action which holds the knees together will be painful. Outward movement of the hip will be restricted by spasm and pain. Complete ruptures are uncommon.
The simple test of the doctor trying to part the knees while the patient is lying flat is usually the only investigation required, unless further damage is suspected in an elite sportsperson, when an ultrasound or muscle scan might be applicable.
What else could it be?
This is where the difficulties start, as the symptoms may be very similar to those experienced where the pubic bones meet at the front of the groin, or where you have suffered a so-called sports hernia. Osteoarthritis of the hip joint may also refer pain to the inner thigh.
There are only so many ways in which one can write RICE, but it is by far the most appropriate treatment in the early stages. You should not deviate from its use, continuing the treatment during rehabilitation. The most effective exercise to stretch the muscles safely resembles the yogic lotus position.
A doctor and a physiotherapist will be able to guide appropriate stretching while electrical treatments are used, and advise on the use of optimum stretching required before strength is gained, using exercises which pull the knees together.
Can you run through it?/Recovery time
These injuries are slow to heal and over-enthusiasm may again risk scar tissue changing to bone. It is far better to write off two months during which you rehabilitate properly, than to risk many more with inappropriate treatment.
Written by: Patrick Milroy