14 Jun, 13 | by Karim Khan
Sport and Exercise Medicine: The UK trainee perspective (A BJSM blog series)
By Dr James Noake
In clinic last week my orthopaedic colleague whispered to me, “So tell me more about this AposTherapy? That’s the third patient this week to quiz me about it”. Admittedly I had only ever cast a cursory (sceptical) eye over the advertisements, which seem to have become ubiquitous in the UK.
The official website claims the therapy is “clinically proven for long-lasting pain relief” in several musculoskeletal conditions including knee OA, patellofemoral syndrome and chronic lower back pain. Further investigation reveals an intervention which operates on the principal of altering gait kinematics, re-distribution of joint contact forces and improving neuromuscular control via an orthotic device – but interestingly worn on the external surface (sole) of a customised shoe.
Aesthetically it leaves a lot to be desired and the adjustable mechanism appears crude, but before we sneer, consider that clinicians probably responded in a similar fashion years ago when some bright spark suggested we insert a device into our shoes to influence the proximal kinetic chain.
The evidence base to date is comprised of retrospective, prospective and controlled (non-randomised) trials, which show significant improvement in short and long-term outcomes (WOMAC scores) and improvement in gait velocity, cadence and stride length1,2. A biomechanical study3 demonstrates that manipulating the foot centre of pressure during gait positively alters activation patterns of the lower limb musculature, particularly knee adduction moments, lending some scientific credence to the mechanism of action.
Although one could certainly pick holes in the methodology and quality of the research, it is still enough to pique interest in this non-invasive, relatively low cost treatment. It is however very easy to dismiss this type of product as being “gimmicky”, rather than to appraise it objectively. The outcome of a rigorous RCT with greater numbers would be very interesting.
‘Time to get your feet dirty…..’
As SEM clinicians, patients and friends have asked us for expert opinion about the positive and negative effects of ‘bare-foot’ running, and just as often, which trainer to choose out of the bewildering array of choice on the current market.
As a specialty we are starting to gain a scientific understanding of how a mid-foot strike running style might improve symptoms in patients with Chronic Exertional Compartment Syndrome (CECS) and how a holistic running re-education approach can ameliorate Exercise Induced Leg Pain (EILP), as demonstrated by ongoing work at Headley Court DMRC. However, there is no medical consensus with respect to the most suitable footwear type.
Therefore it was with interest that I read the recent BJSM biomechanical study4, which definitively demonstrated that running shod, including in a so-called ‘minimalist’ shoe, does not replicate true bare foot running style. There are significant differences between the kinetic and kinematic variables at the foot and ankle during gait analysis.
Given these results, we now need to address our patients’ misconceptions about the efficacy of different shoe types, principally driven by the misleading advertising of manufacturers and reinforced by well-meaning but ultimately financially driven store assistants. It seems that if patients want to benefit from a change in running style, then they may well have to throw their trainers away completely.
‘Subtalar arthroereisis – the surgical orthotic?’
Whilst recently exploring options for a patient with (correctable) pes planus deformity with persistent pain due to chronic overload of the medial mid-foot structures and tibialis posterior tendon, I happened across this procedure, which involves insertion of a screw or self-locking wedge into the sinus tarsi. I assumed it was an experimental procedure but to my surprise it was first utilized in 1946.
The implant is intended to block anterior, inferior, and medial displacement of the talus in resting stance and gait (and consequently prevent collapse of the mid-foot) as well as preventing excessive eversion of the rear-foot.
It seems to me that this might be an end-stage option for less active patients for whom customized footwear appliances and physical therapy have failed. Certainly biomechanical studies exist that show there is significant variability in patients’ response to orthoses and that their positive effects on subtalar motion are typically small during gait analysis5, so would a definitive surgical block off-load the tissues under stress more effectively?
It makes sense that the implant needs to be inserted bilaterally even if symptoms were unilateral to prevent compensatory problems. My main concern is that the rigid implant would cause a ‘stress riser’ over time in the adjacent bone, leading to stress (and ultimately frank) fracture, much in the same way peri-prosthetic fractures occur. Research to date does not corroborate this however6.
Dr James Noake is a Sport and Exercise Medicine trainee currently placed at Homerton Hospital, London. He is Head Doctor at London Irish RFC, works as a medical officer for England / GB Disability Football and is clinical lead in orthopaedics, SEM and musculoskeletal medicine for Herts Valleys Clinical Commissioning Group (HVCCG). He has a special interest in foot and ankle disorders in sport.
Dr James Thing co-ordinates “Sport and Exercise Medicine: The UK trainee perspective” monthly blog series.
- Bar-Ziv et al. A 2 year follow up study indicated AposTherapy provides lasting pain relief and long term improved function. Arthritis 2012.
- Elbaz A, Mor A et al. APOS Therapy Improves Clinical Measurements and Gait in Patients with Knee OA. Clinical Biomechanics 2010, 25:920-5.
- Haim A, Rozen N et al. Control of knee coronal plane moment via modulation of center of pressure: a prospective gait analysis study. Journal of Biomechanics 2008, 41: 3010–3016.
- Bonacci J, Saunders P, Hicks A et al. Running in a minimalist and lightweight shoe is not the same as running barefoot: a biomechanical study. Br J Sports Med 2013; 47: 6. 387-392.
- Mills K, Blanch P et al. Foot orthoses and gait: a systematic review and meta-analysis of literature pertaining to potential mechanisms. Br J Sports Med 2010; 44: 1035-1046.
- Van Ooij B, Vos CJ, Saouti R. Arthroereisis of the subtalar joint: an uncommon complication and literature review. J Foot Ankle Surg. 2012; 51(1): 114-117.