A groin strain is a tear or rupture to any of the adductor muscles on the inside of the thigh. Symptoms include a sudden sharp pain in the thigh which can range from a quite mild niggling injury to very severe injuries that are completely debilitating. Explosive movements and changing direction quickly can cause groin pain, especially if you haven't warmed up properly and have tight adductor muscles.
Here we explain initial treatment during the early acute stage followed by a full rehabilitation and strengthening program.
The main symptom of a groin strain is a sudden sharp pain in the groin area, either in the belly of the muscle or higher up where the tendon attaches to the pelvic bone. It might be felt when sprinting or changing direction quickly. The athlete may or may not be able to play on depending on how severe the injury is.
Although there is often swelling (oedema) as a result of a groin strain this is often not visible to the naked eye. Groin strains are graded 1, 2 or 3 depending on the extent of the injury.
Grade 1 - A Grade 1 strain is a minor tear where less than 25% of fibers are damaged. Discomfort in the groin or inner thigh will be felt but the athlete can often walk with minimal or no pain. They may often be unable to recall exactly when the injury occurred and the pain in the muscle may only be noticed after exercising. The groin muscles may feel tight and tender to touch. Pain on stretching the groin muscle may be present, especially when compared to stretching the groin muscles on the opposite leg and the injury will be felt when performing explosive type movements.
Grade 2 - A Grade 2 injury is a moderate tear which involves damage to more than 25% of fibres. The athlete will often know when the injury occurred and will feel a sudden sharp pain in the groin (adductor) muscles during exercise. Bruising and swelling will usually develop over the next few days but this may not be visible to the naked eye. The injured muscle will be weak and painful when attempting to contract the muscle - this is easily tested by squeezing your legs together with a ball between your knees. Pain will also be felt on stretching the groin muscles.
Grade 3 - Grade 3 strains are the most serious and involve either a complete (100%) or almost complete rupture of the muscle. The main symptom of a Grade 3 tear is severe pain during exercise with the athlete unable to continue. They will be unable to contract the groin muscles when squeezing the legs together and due to a combination of weakness and pain. Substantial swelling and bruising will usually develop around the inner thigh area and this may become visible within 24 to 48 hours.
Learn more about assessment and diagnosis.
Causes & anatomy
Groin strains usually occur when sprinting or changing direction quickly or during rapid movements of the leg against resistance such as kicking a ball. Overstretching the muscle such as in martial arts high kicks can also cause a torn adductor muscle.
The main function of the adductor muscle group is to pull the leg back towards the midline, a movement called adduction. They also stabilize and control the pelvis during movement of the legs during most activities including walking, running, sprinting, playing football, horse riding, hurdling and any sport which requires rapid changes in direction. This is achieved by the adductor muscles on one side keeping the pelvis level and still while the adductor muscles on the opposite side are used to move the leg.
There are five groin (adductor) muscles; three of them are called the 'short adductors' (pectineus, adductor brevis, and adductor longus) and the other two are called the 'long adductors' and consist of gracilis and adductor Magnus. Although muscle strains can occur randomly there are factors which can increase the likelihood of sustaining an injury. These include not warming up properly, having weak adductor muscles, tight adductor muscles, previous injury, lower back problems and biomechanical factors.
Treatment & Rehabilitation
The Sportsinjuryclinic.net groin strain rehabilitation program is based on four strands or pathways of treatment (ice, heat, massage etc), stretching, strengthening and maintaining fitness. As each injury and each athlete is different they may start at a different point and progress at different rates.
Apply the P.R.I.C.E principles (protection, rest, ice, compression and elevation) as soon as possible after the injury and for the first 72 hours. A cold therapy and compression wrap will help stop internal bleeding, reduce pain and swelling speeding up the healing process. Wearing a groin support or groin strapping (see below) is also useful in the early stages in order to minimise pain and support the muscle while it heals. The use of groin supports and compression shorts is useful to protect and support the muscle when returning to training.
After the initial acute stage, a progressive stretching and strengthening exercise program is advised to ensure the muscle regains pre-injury levels of strength and flexibility and is, therefore, less prone to re-injury.
What can a professional therapist/doctor do?
A professional therapist will assess the injury and make an accurate diagnosis. Electrotherapy modalities such as ultrasound may be used to aid the healing process. A doctor may prescribe NSAID medication such as Ibuprofen (do not take if you have asthma) to help with pain and swelling.
Sports massage may be beneficial once the acute stage has passed (after 72 hours) by releasing tension in the muscle and encouraging blood flow and nutrients. Caution is advised as massaging an injury too soon may increase the bleeding and may make the injury worse.
Read more on groin strain treatment & rehabilitation.
Groin rehabilitation exercises
After the initial acute stage of the injury has passed, a gradual rehabilitation program consisting of stretching and strengthening exercises should begin.
Stretching should always be pain-free starting with gentle static stretches where the athlete eases into the stretch and hold for up to 30 seconds, repeating five times a day. Long adductor stretch (legs straight), short adductor stretch (legs bent) and hip flexor stretching should be done ensuring all groin muscles are stretched.
These are progressed as the muscle heals to more dynamic exercises which involve movement or swinging of the leg. Do not start stretching too early as the healing of the muscle may be compromised (not before day 5 post-injury).
Read more and watch videos on stretching exercises.
The aim to gradually increase the load that is put through a muscle and can start as early as day 5 as long as they are low-level and pain-free. Isometric or static exercises are advised first and do not involve any movement of the muscle. For example, squeezing a medicine ball between the knees, or using a partner or therapist for resistance.
Eccentric exercises are more advanced exercises which focus on strengthening the muscle whilst it lengthens rather than shortens as all the previous exercises have done. A therapist or partner is needed to assist with this one. Dynamic exercises with resistance band are performed as the muscle gains in strength.
Straight leg raise and more advanced adduction exercises using gravity or resistance bands are done as pain allows leading on to even more dynamic and sports specific exercises which involve running, change of direction drills, hopping and plyometric exercises. These bridge the gap between rehabilitation exercises and returning to full training and competition.
For a detailed list of strengthening and functional exercises read more and watch videos on groin strain exercises.