What is it?
Hip Flexor or Iliopsoas Related Groin Pain is pain related to the hip flexor muscles at the front of the hip, with the main hip flexor being the iliopsoas muscle. The iliopsoas muscle is made up of two parts – the psoas muscle that starts at the lower back (lumbar spine), and the iliacus that starts from the inside of the pelvis. These muscles run together through the pelvis, over the front of the pelvic rim and deep across the front of the hip. The 2 muscles merge together at the front of the hip (the iliopsoas), where they develop tendons that join into the top of the thigh (femur). Tendons are fibrous structures that attach muscles to bone. The iliopsoas is separated from the hip joint by a large bursa (iliopectineal or iliopsoas bursa). This bursa (soft pad) reduces friction and helps the tendons slide freely across the front of the hip
Hip flexor pain or iliopsoas related groin pain may be related to the muscles themselves, the junction between the muscle and the tendon (the musculotendinous junction), the tendon or the bursa. Various terms may be used to diagnose hip flexor conditions, including:
- Hip flexor strain or tear; iliopsoas strain or tear – usually related to a known injury
- iliopsoas tendinopathy – a painful iliopsoas tendon, usually developing more slowly over time
- anterior snapping hip – snapping of the iliopsoas tendon which can sometimes become painful
- iliopsoas bursitis – inflammation or thickening of the iliopsoas bursa
- iliopsoas impingement – impingement or compression of the iliopsoas tendon against the underlying bone or artificial hip (hip prosthesis)
What are the usual symptoms of hip flexor/iliopsoas related groin pain?
People with hip flexor or iliopsoas related groin pain usually have pain around the front of the hip and the upper thigh. Pain may extend into the lower abdomen and even lower back sometimes. It is usually described as deep discomfort or tightness.
Pain or symptoms from iliopsoas related groin pain is usually felt around the front of the hip when:
- Bringing the knee up towards the chest (hip flexion)
- Stretching the leg behind you (hip extension)
Athletes may develop symptoms when running, particularly when sprinting, and when kicking. There may be difficulty with accelerating to full speed, striding out or changing direction when running, or kicking with full power. Lower back tightness, fatigue or aching may develop during longer runs or periods of activity.
Other symptoms may include a snapping sensation at the front of the hip which most commonly occurs when moving from a position of hip flexion to hip extension – for example, when lifting and lowering the leg during dressing or when doing abdominal exercises whilst lying on the back with the legs cycling in the air. Snapping is common in young, flexible people and particularly dancers, but is not usually a problem unless there is pain involved.
With more severe hip flexor pain or after hip flexor trauma or surgery, everyday movement tasks such as walking upstairs, dressing or lifting the leg in and out of bed or the car may also be difficult.
What causes it?
The pain of iliopsoas related groin pain may develop rapidly or slowly over time, without a clear injury. Rapid onset may be associated with an injury sustained during activities involving kicking, sprinting, tackling and sliding. The most common mechanism of injury found in one study, was changing direction while running. This is usually related to a hip flexor strain or tear. Pain may also develop more slowly over time related to repetitive overload of the hip flexors or surgical interventions.
Contributing factors may include:
- Sports requiring lots of hip flexion (knee to chest) or hip extension (taking the leg behind you). Examples include sprinting, rowing, ballet and martial arts
- Particular postures and movement patterns that increase load placed on the hip flexors
- Previous surgery – arthroscopy (keyhole surgery) or total hip replacement
- Either greater than or less than average flexibility of the hip
Iliopsoas related groin pain is common in runners but may also occur in speed or power walkers. Symptoms tend to increase with both of these groups when speed or distance is increased, particularly if the individual has longer stride lengths. This is because the hip is being stretched behind the body more (i.e. into hip extension), putting higher strains across the hip flexors.
Athletes using their hips in higher ranges of motion or in forceful hip flexor actions such as dancers, gymnasts, martial artists and football players may develop iliopsoas related groin pain either rapidly or slowly over time from repetitive overuse.
Iliopsoas related pain can develop after hip surgery – either hip arthroscopy (keyhole surgery) or total hip replacement. This is because of things that have happened directly under the hip flexors, at the hip joint. The iliopsoas may sometimes become painful due to the relationship between the tendon and the artificial hip sitting beneath it – this is referred to as iliopsoas impingement.
While hip flexor or iliopsoas related pain is often assumed to be due to tightness of the hip flexors, perhaps even more commonly health professionals see hip flexor problems in flexible people with longer than normal hip flexors, who stand and move with greater load on the hip flexors.
Getting Help. What is the usual treatment?
- Gaining an understanding of what the problem is and how to stop provoking it, is the first important step. This is often called ‘load management’. Your Hip Pain Professional can identify specific aggravating factors and provide individualised advice. Things you do regularly may be making the situation worse. For example, stretching into hip extension (thigh back behind the body) is usually not recommended for hip flexor or iliopsoas related groin pain. A formal assessment of your hip flexor length is necessary to determine if lengthening is required and the safest way to improve flexibility of the hip flexors. A Hip Pain Professional will also discuss other things that may be aggravating your condition and specific strategies that will be beneficial in alleviating pain in your situation.
A specific, graduated and individualised exercise program is the other main aspect of treatment. Improvements can occur quickly, particularly if you have caught the problem early. If you have had the condition for a long time, progress may be slower.
An exercise program can have many benefits such as:
- improving health and co-ordination of the hip, trunk (abdominal and back) and thigh muscles
- improving awareness and control of hip and pelvic position during standing and moving, to reduce unnecessary or excessive strain on the hip flexors
- improving muscle strength and tolerance of physical loads
- reducing pain
- improving ability to perform normal daily tasks
- increasing confidence in your ability to do things
- returning to full activity and sport
- improving quality of life
- safely lengthening the hip flexors if and when required
Cortisone (corticosteroid) injections usually only provide short¬ term relief. Cortisone may also reduce health of the tendons, particularly with repeated injections. So, it is usually best to commit to an education and exercise approach first.
- Surgery is a last resort and is usually only considered after 12 months of other treatments, unless pain and disability is severe. Several studies have also reported potential concerns regarding surgery. For example, arthroscopic release of the iliopsoas tendon may increase the risk of hip joint instability (Austin et al. 2014, Sansone et al. 2013, Yeung et al. 2016). Iliopsoas release may also result in reduced hip flexor strength and function. Therefore, a surgeon will always consider the relative risks and benefits of such a surgery and discuss these with you before a decision is made. Any surgical procedure should be followed with a rehabilitation program.
There are many options for managing the symptoms of hip flexor/iliopsoas related groin pain. The most important place to start is with advice and exercise approaches from a professional with knowledge of the available evidence. Although injections and surgery are sometimes unavoidable, when these are necessary, combining a rehabilitation program provides the best functional outcome. A Hip Pain Professional can assist with this rehabilitation.
A Hip Pain Professional can assist you with your hip flexor related pain by providing:
- Skilled assessment
- Advice and Education
- Quality treatment
- Appropriate Referral
Sansone M, Ahlden M, Jonasson P, Sward L, Eriksson T, Karlsson J. Total dislocation of the hip joint after arthroscopy and iliopsoas tenotomy. Knee Surgery, Sports Traumatology, Arthroscopy 2013;21(2):420-423
Yeung M, Memon M, Simunovic N et at. Gross instability after hip arthroscopy: an analysis of case reports evaluating surgical and patient factors. Arthroscopy: The Journal of Arthroscopic and Related Surgery 2016;32(6):1196-1204