Most active people who present to the physiotherapy clinic with lower-limb overuse injuries are straightforward cases to diagnose. Their movement patterns and underlying biomechanics correlate with their injury history and identified painful structures, allowing the therapist to make an accurate diagnosis and set an effective rehabilitation plan.
Typically we may see medial tibial stress syndrome, Achilles or patella tendinosis or plantar fasciitis all commonly resulting from the combined presentation of excessive pronation, failure to take off a resupinated foot (when the foot retightens after the shock-absorbing pronation movement) and inadequate control through VMO and hip and pelvis musculature.
Not every patient fits the mould so neatly. Sarah came to physiotherapy with painful knees and a goal. She wanted to go hiking in South America in three months’ time and had already signed up for a trip – a leap of faith for a young lady who for several years had suffered posterior knee pain bilaterally whenever she walked any considerable distance. For Sarah, hiking had always been a passion seriously limited by her undiagnosed knee pain.
I knew Sarah was going to be an interesting patient. On observation she had a tendency towards hypermobility and stood with hyperextended knees. She had a particularly high arch profile bilaterally. And she had a serious lack of calf musculature compared to the development through her gluts. Her gait assessment matched almost perfectly what you would expect from these postural observations. She had very poor calf muscle propulsion at the end of her stance phase and as a result had an increased stride length and a very late jolt into hyperextension through her tibiofemoral joint.
This prompted me to test her calf muscle endurance with single-leg calf raises on the edge of a step. She could only manage six on the right and seven on the left before fatiguing. Her inner range quadriceps control was also very poor. It is no wonder that, on testing her calf muscle length, she could barely even find a stretch. While many patients suffer with perpetually tight calve muscles, Sarah had too much length in hers, and wasn’t using them at all to walk.
If the calve muscles fail to propel at the end of stance phase, the consequences for gait control can be seen both locally and up and down the kinetic chain. Locally there may be tensile overload through the tendoachilles complex and subsequent tendinopathy. The patient may habitually take off from a pronated foot which can lead to overload of the plantar fascia, peroneal longus tendon or mid-tarsal joints; or, as in Sarah’s case, to hyperextension of the tibiofemoral joint.
Up the kinetic chain, an increased stride length can cause an increased anterior pelvic tilt at the end of stance phase, particularly if there is a anterior restriction of the hip joint, such as tight hip flexors. If the calf muscles are doing less, then the body will try to propel from somewhere and this may come from the gluts – or more usually from the hamstrings and lumbar spine extensors.
Sarah, fortunately, recruited her gluts very well, thereby managing to avoid the more detrimental symptoms of low back, hip or pelvic pain that she might otherwise have had. Just as it is important to assess for a lack of propulsion, often you will find patients recruiting their calve muscles too early in the gait cycle. This early heel lift will produce injuries associated with being too short through the calf/soleus complex.
My provisional diagnosis for Sarah was that her lack of calf muscle strength and endurance, and her poor inner range knee control were responsible for her poor gait pattern. Her hyperextension of the tibiofemoral joint was then irritating the structures at the back of the knee. With further testing I ruled out any significant injury to the meniscus and cartilage, adverse neural tension or referred pain and hamstring tendinopathy. There was a chance that Sarah had a benign growth in the popliteal fossa, but I initially excluded this because of the bilateral nature and history of the injury.
I put Sarah on to exercise rehabilitation and gait re-education. She did single-leg calf raises on a step, aiming for high repetitions to increase strength and endurance, and also to start recruiting the muscles. While performing single-leg squats and lunges, Sarah had to focus on inner range knee control by maintaining good knee alignment and practising tightening through her quads, stopping just before the end of range of extension. After two weeks of remedial exercises I introduced some new rules to Sarah’s gait.
To change how anyone walks is difficult at first, but good results are very achievable. I find it easiest to introduce simple cues to avoid confusing the patient. Sarah had to concentrate on three things, all of which went hand in hand:
For the first couple of weeks, Sarah found her new walking pattern difficult. After eight weeks, though, she had built up significant improvements in strength and control with the exercises and she was feeling much more comfortable with her new walking style.
At 10 weeks Sarah was a happy camper. She had hiked for four hours in rugged terrain with minimal discomfort and she was packing her bags for a wonderful trip.