Introduction. Shoes with a rocker sole are commonly prescribed following forefoot surgery to redistribute pressure towards the heel. By shifting the body weight backwards, does the rocker shoe adversely effect balance and so disturb normal muscle activity? This study investigated the effects of the Darco post-operative shoe, and the impact of a contralateral shoe raise, on forefoot pressure, posture and balance. Materials and Methods. Fourteen healthy volunteers were investigated (age 36 ±10.8 yrs 11 females) either wearing (1) left Darco shoe and right standard shoe with/without a 5cm temporary shoe raise (Algeos Ltd) (2) two standard shoes. Postural sway was measured while standing with eyes open/closed and on/off a foam block. Dynamic balance was measured while stepping forwards/backwards and walking. Measurements of foot pressure (TECSKAN Inc USA), 3D body motion (Codamotion, UK) and surface electromyography of lower limb muscles were taken. Results were analysed using a repeated measures ANOVA. Results. The rocker shoe was associated with a 84% (±14) decrease in mean peak medial forefoot pressure a posterior shift of 0.9 cm (±1) in the centre of pressure (COP) and a 223% (±127) increase in tibialis anterior activity (P<0.05). Postural sway and whole body motion while stepping did not change. The shoe raise decreased peak loading in the Darco shoe and resulted in a smaller shift in the COP. Discussion and Conclusions. The increase in tibialis anterior activity helps maintain balance by compensating for the posterior shift in the centre of pressure. In people with weakness in the anterior muscles a rocker shoe may adversely affect balance. A contralateral shoe raise reduces the posterior shift in the COP but, due to a decrease in total loading through the whole foot, forefoot offloading is similar. A contralateral shoe raise may therefore aid balance while maintaining forefoot offloading

Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%.

There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions.

Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group.

Cite this article: Bone Joint J 2013;95-B:192–8.