Groin pain: A niggle not to ignore
Author: By Doug James, intraining Physiotherapist, Podiatr
Groin pain is a less frequent complaint in runners compared to athletes involved in kicking sports such as soccer but still accounts for around 2-5% of injuries. Despite being uncommon, it is important for all runners to be aware of the risk of neglecting an injury in this region as it may require 12 months or more off running. Groin and pelvic injuries can begin as a fairly ‘harmless’ muscle strain to the inner thigh, however, if improperly managed often results in the development of multiple slow healing serious injuries with long-lasting consequences.
Anatomy of the region
The pelvis is a bowl-like structure that provides attachment points for our legs and spine, and a number of muscles important for movement. It consists of left and right side bones, each of which has an attachment for its respective femur (thigh bone). At the rear, the pelvic bones connect to the lowest part of the spine – the sacrum – forming the stiff and stable Sacro-Illiac joints (SIJ). In the lower front part of the pelvis is a small gap filled with a cartilage disc called the Pubic Symphysis (PS), which allows for small amounts of movement. The PS works to cushion and dissipate impact forces generated during gait. Impact forces during walking equate to around 1 to 1.5 times your bodyweight. During running this can increase to 3 to 4 times your bodyweight from landing forces and propulsion.
During running, loading force is applied to the pelvis and is rapidly shifted from side to side with each step. These loading forces are borne through the PS and amplified during higher intensity running – including interval training, downhill running, or sudden changes in direction (as often occurs during trail running or in crowded race situations). Kicking and jumping activities further increase the load on the PS, hence the increased incidence in sports such as Australian rules football and soccer.
How does it develop?
Injury to the PS can occur in isolation – particularly during pregnancy- but is usually injured in conjunction with, or following an injury to a nearby structure such as an Adductor muscle tendon. The PS is central to a number of muscle-tendon attachments including the Adductors (inner thigh) and Rectus Abdominus (‘six-pack’ stomach muscles) and is therefore subject to strain from a number of different directions.
Given the central location of the PS and its important role in load absorption and transfer, muscle imbalances tend to increase the risk of damage to this and neighbouring structures. Weakness in the lateral Gluteal muscles (Medius and Minimus) and Adductor muscles results in pelvic instability particularly during the initial loading phase of gait. At this point, peak forces rapidly increase and the PS’s ability to handle these loads can begin to fail to result in damage to the PS and nearby cartilage lining and bone. The damage often results in a split in the cartilage and bruising within the pelvic bone, both of which causes a painful condition traditionally known as ‘Osteitis Pubis’.
The term ‘Osteitis Pubis’ – which roughly means ‘inflamed pubic bone’ – has in more recent times been renamed ‘Longstanding groin pain’ to reflect the fact that the injury doesn’t simply just affect the bone. The new moniker also portrays the protracted healing time of the injury. Diagnosis is made via a series of clinical tests (usually by a Physio or Sports Doctor), with MRI scans proving useful to determine the presence and extent of the injury. Details of recent training history and related aches and pains can help determine when things started to go wrong. Injuries of this type don’t occur spontaneously during a single run, and there are often a number of warning signs to watch out for.
What do I need to watch out for?
A feeling of tightness in the inner thigh and hamstrings is a commonly reported symptom in the early stage of the condition. This tightness usually follows an adductor injury, but can arise after a sudden and steep increase in training distance, intensity or both. The mid to upper thigh soreness often pre-dates any specific groin pain and can begin as a mild discomfort without a specific strain type injury occurring. If training continues, the symptoms tend to become more severe, with stronger, sharper pain being felt in the central groin region which is often felt continuously even when not exercising. Eventually, running becomes too painful, and even walking (particularly on stairs) can be quite uncomfortable.
Treatment and recovery?
As with many bone injuries, a period of rest from weight bearing exercise is necessary, though it tends to be much longer with this injury. Instead of the usual 6-8 weeks rest, upwards of 3 months may be required to allow the bone sufficient time to heal. During this time, even lower impact activities such as walking and swimming need to be restricted. Due to the multifaceted nature of the injury, muscle imbalances and adductor tendinitis (if present) will also need to be properly treated before attempting returning to running or impact exercise. In some cases, 12 months may pass before the injury has properly healed to the extent where a return to running plan can be considered. With early diagnosis and good adherence to rehabilitation guidelines, a return to running can be possible in as little as 5 or 6 months.
How to avoid it?
Since the injury doesn’t spontaneously develop, there are usually a number of chances to halt the injury from developing. Following a training plan that takes into account your running history, current conditioning, and allows for a gradual and periodic increase in training load can help. Particular care should be taken by any runners that also compete in kicking sports. Additionally, having any adductor injuries treated promptly by a Physio may help reduce the risk of further injuries such as ‘Longstanding groin pain’ developing.
If you are concerned about an injury that isn’t improving, contact the intraining Running Injury Clinic to book an appointment. Our podiatrists and physiotherapists are all runners.