Lateral hip pain. Gluteus medius tendinopathy. Common causes, prevalence, assessment, education and management; an exercise physiology approach.
If you’re walking like a pirate but don’t captain a large ship, your swagger may be preventable and treatable, and the remedy doesn’t involve buying an eye-path and a parrot. Gluteus medius tendinopathy (GMt) is a relatively common condition that affects the outside of the hip. The gluteus medius (glut med) muscle is a powerful abductor and internal rotator that primarily acts to stabilise the hips during walking and running. Overload of the glut med muscle or excessive compression of the tendon on the greater trochanter (hip bone) can result in GMt.
Lateral hip pain has traditionally been referred to as trochanteric bursitis, however recent studies have shown that inflammation of the bursae is almost always secondary to glut med or glut min tendinopathy (Kong et al. 2007, Pfirrmann et al. 2005, Woodley et al. 2007).
The primary role of tendons is to transfer load. When too much load is repetitively placed on the tendon (walking/stair climbing), it becomes irritated, which can lead to tendinopathy. Tendinopathy is essentially tendon irritation resulting in changes to the structure of the tendon, making it more susceptible to further damage and ultimately reducing its ability to transfer load.
There are two prime contributing factors:
· Compression is thought to be a key factor in the development of insertional tendinopathies and needs to be taken into consideration in any rehabilitation program (Cook & Purdam 2009; Maffulli et al, 2003).
· History of increase in load over previous weeks, such as a long walk (Camino De Santiago anyone?), power walking, hills, stairs, running, hopping, skipping, horse riding; just about any action that results in repetitive flexion through the hip.
As with most non-contact injuries, the main causes are biomechanics and load. The main ways people typically overload their GMt are by walking and running with a slightly altered gait pattern (possibly secondarily due to a sore back, hip or knee) or weakness in their glut max muscle. The glut max muscle helps to control the movement of the hip and if it is dysfunctional (or just plain lazy), it will increase the load on other structures such as glut med.
GMt is much more prevalent in females (particularly post-menopausal) than males with a ratio of 4:1, however it can also effect young athletes, particularly runners or recreational athletes participating in stair running, step aerobics or hill sprints. Degenerative tears of glut med or min occur in 20% of patients with osteoarthritis of the hip (Howell et al. 2001). GMt occurs in 20–35% of patients with low back pain (Collee et al. 1991, Tortolani et al. 2002). Due to the pattern of referred pain from the greater trochanter down the lateral thigh, it is often misdiagnosed as low back pain, which can lead to unnecessary and ineffective treatment.
· Lateral hip pain
· Hip pain can extend into lateral thigh
· Hip pain often worse at night
· Getting into and out of a car
· Standing on one leg
· Climbing stairs
· Walking at normal speed or up gradient
Differential Diagnosis of Lateral Hip Pain
· Hip osteoarthritis
· Snapping hip syndrome
· Meralgia paresthetica
· SIJ dysfunction
Basic Clinic Testing and Assessing
Modified Trendelenburg Test
· Reproduction of hip pain around greater trochanter
· Inability to maximally elevate the pelvis or to maintain maximal elevation for 30 secs
· Reproduction of pain around lateral thigh if presenting symptom
FABER, looking for greater trochanter pain with no loss of motion
FADIR, to monitor compression of tendons as provocative test – adds tensile load on tendon while being compressed
Modified Obers test, using compression to provoke the tendon at lateral hip
Palpation, tenderness on palpation is highly sensitive and has greatest negative likelihood ratio
Where to Start
· Minimise compressive load
· Avoid aggravating activities
· Educate about standing, sitting, walking, and sleeping postures
· Improve posture and gait patterns
· Positively load the tendon with exercise to add more torque in the tendon and create some positive changes in the tendon over time
To Rest or Not to Rest?
Below is a crude, but very simple graph I like to draw for patients. The thick black line represents the tendons current tolerance or threshold to load. The wavy line represents the load such as running, stairs, walking or hills being exerted on the musculotendinous unit. You can see how resting the tendon may help alleviate symptoms by avoiding aggravating activities, however the tendon will be increasingly susceptible to load with increased rest. Quite simply, load greater than capacity will result in injury, flare ups, and set backs. Gradually increasing the capacity will enhance the tendons ability to tolerate load while avoiding hip pain and discomfort.
The Benefits of Isometrics in Reducing Hip Pain
Recent studies have demonstrated that isometric exercise can inhibit the tendons pain response while still allowing load to be placed on the tendon. Isometrics also make it possible to add load without compression, a worthwhile consideration.
Exercises / Postural Re-education
Isometric abduction (low load through glut med and min)
· Avoid over-recruitment of tensor fascia latae
· Used as pain relief and to develop motor control
· Use pillows to prevent adduction
· Can be supine or side-lying
· Moderate range of motion
· Standing hip abduction
· Eccentric control of hip adductors
· Gradually load tendon without compression
Strengthening to improve functional alignment control
· Sit to stands
Single leg stance and single leg squats
· Gradually reduce balance support
The Role of Exercise Physiology
As stated above, GMt is primarily caused by altered biomechanics and muscle activation patterns. Exercise physiology serves to correct these issues by improving walking gait (biomechanics and posture) and improving muscle activation patterns by strengthening key muscles such as core muscles, glut max, and glut med. For a GMt rehabilitation program to be effective, education is paramount as this will result in reduced hip pain, better adherence, improved postural awareness, and better long term results.
Advice for Patients to Avoid Hip Pain
· Avoid compressing the tendon (crossing legs, standing with more weight on one leg)
· Place a pillow between your knees if sleeping on one side
· Avoid low sitting (couches, car seats)
· Avoid excessive stretching
Finally, sea legs may be good fun, but they should only be temporary. Walking with an altered gait will increase the load on the glut med muscle and adds further compression to the tendon, resulting in lateral hip pain. Encourage people to walk normally if possible and avoid rest as it will only further weaken the musculotendinous complex.