Aims. The purpose of this study was to analyse the biomechanics of walking, through the ground reaction forces (GRF) measured, after first metatarsal osteotomy or metatarsophalangeal joint (MTP) arthrodesis. Patients and Methods. A total of 19 patients underwent a Scarf osteotomy (50.3 years, standard deviation (. sd. ) 12.3) and 18 underwent an arthrodesis (56.2 years,. sd. 6.5). Clinical and radiographical data as well as the American Orthopaedic Foot and Ankle Society (AOFAS) scores were determined. GRF were measured using an instrumented treadmill. A two-way model of analysis of variance (ANOVA) was used to determine the effects of surgery on biomechanical parameters of walking, particularly propulsion. Results. Epidemiological, radiographical and clinical data were comparable in the two groups and better restoration of propulsive function was found after osteotomy as shown by ANOVA (two way: surgery × foot) with a surgery effect on vertical forces (p < 0.01) and a foot effect on anteroposterior impulse (p = 0.01). Conclusion. Patients who underwent Scarf osteotomy had a gait pattern similar to that of their non-operated foot, whereas those who underwent arthrodesis of the first (metatarsophalangeal) MTP joint did not totally recover the propulsive forces of the forefoot. Take home message: The main findings of this study were that after surgical correction for hallux valgus, patients who underwent scarf osteotomy had a gait pattern similar to that of their non-operated foot in terms of forefoot propulsive forces (Fz3, Iy2), whereas those who underwent arthrodesis of the first MTP joint had not. Cite this article: Bone Joint J 2016;98-B:641–6

Aims. This cross-sectional study aimed to investigate the in vivo ankle kinetic alterations in patients with concomitant chronic ankle instability (CAI) and osteochondral lesion of the talus (OLT), which may offer opportunities for clinician intervention in treatment and rehabilitation. Methods. A total of 16 subjects with CAI (eight without OLT and eight with OLT) and eight healthy subjects underwent gait analysis in a stair descent setting. Inverse dynamic analysis was applied to ground reaction forces and marker trajectories using the AnyBody Modeling System. One-dimensional statistical parametric mapping was performed to compare ankle joint reaction force and joint moment curve among groups. Results. The patients with OLT showed significantly increased dorsiflexion moment in the ankle joint compared with healthy subjects during 38.2% to 40.9% of the gait cycle, and increased eversion moment in the ankle joint compared with patients without OLT during 25.5% to 27.6% of the gait cycle. Compared with healthy subjects, the patients with OLT showed increased anterior force during 42% to 43% of the gait cycle, and maximal medial force (p = 0.005, ηp2 = 0.399). Conclusion. The patients with concomitant CAI and OLT exhibit increased dorsiflexion and eversion moment, as well as increased anterior and medial ankle joint reaction force during stair descent, compared with patients with CAI but without OLT and healthy subjects, respectively. Thus, a rehabilitative regimen targeting excessive ankle dorsiflexion and eversion moment may help to reduce ankle joint loading. Cite this article: Bone Joint Res 2024;13(12):716–724

It has been suggested that extracorporeal shockwave therapy is a safe and effective treatment for pain relief from recalcitrant plantar fasciopathy (PF). However, the changes in gait and associated biomechanical parameters have not been well characterised. We recruited 12 female patients with recalcitrant PF who had a mean age of 59 years (50 to 70) and mean body mass index of 25 kg/m² (22 to 30). The patients reported a mean duration of symptoms of 9.3 months (6 to 15). Shockwave therapy consisting of 1500 impulses (energy flux density 0.26 mJ/mm²) was applied for three sessions, each three weeks apart. A pain visual analogue scale (VAS) rating, plantar pressure assessment and motion analysis were carried out before and nine weeks after first shock wave therapy. It was demonstrated that patients increased their walking velocity and cadence as well indicating a decrease in pain after shockwave therapy. In the symptomatic foot, the peak contact pressure over the forefoot increased and the contact area over the digits decreased. The total foot impulse also decreased as did stance duration. The duration the centre of pressure remained in the hindfoot increased in the symptomatic foot after shockwave therapy. The differences in centre of pressure trajectory at baseline decreased at final follow-up. In conclusion, shockwave therapy not only decreased the pain VAS rating but also improved the gait parameters of the symptomatic foot in PF patients.

Cite this article: Bone Joint J 2013;95-B:1088–93.

Hallux rigidus was first described in 1887. Many aetiological factors have been postulated, but none has been supported by scientific evidence. We have examined the static and dynamic imbalances in the first metatarsophalangeal joint which we postulated could be the cause of this condition. We performed a finite-element analysis study on a male subject and calculated a mathematical model of the joint when subjected to both normal and abnormal physiological loads.

The results gave statistically significant evidence for an increase in tension of the plantar fascia as the cause of abnormal stress on the articular cartilage rather than mismatch of the articular surfaces or subclinical muscle contractures. Our study indicated a clinical potential cause of hallux rigidus and challenged the many aetiological theories. It could influence the choice of surgical procedure for the treatment of early grades of hallux rigidus.