Foot and Ankle Mobilisation in Diabetic Peripheral Neuropathy. Proof of concept RCT with an embedded qualitative component.

Background: The risk of diabetic foot ulceration increases in feet lacking their protective sensation and exposed to repetitive peak plantar pressures (PPPs). Diabetic glycosylation reducing ankle and 1st metatarsophalangeal (MTP-1) movement may further increase PPP and ulceration risk. Manual therapy could restore accessory gliding of the ankle and MTP-1 joints, and along with stretches, improve function and reduce ulcer risk. Aim: Investigate if ankle and MTP-1 joint mobilisations combined with a home exercise programme (HEP) of stretches in people with diabetic peripheral neuropathy (DPN), improve ankle and MTP-1 dorsiflexion (DF) and reduce forefoot PPPs. Methods: A single site, proof of concept, assessor-blinded randomised controlled trial with intervention comprising bilateral ankle and MTP-1 joint mobilisations combined with HEP stretches (gastro-soleus and plantar fascia), delivered over a 6-week period. Participants presenting with DPN and ankle/MTP1 joint stiffness were randomised to an intervention (n=31) or control group (n=30). Active ulceration, arthritis, fracture, osteoporosis or amputation were excluded. The primary outcome was ankle DF in stance phase measured using 3D motion analysis (Codamotion). Secondary outcomes included PPP (F Scan), Static ankle and MTP-1 joint DF, postural sway and functional reach test (FRT). Data was collected at baseline (T0), post-intervention at 6-weeks (T6) and 18-weeks from baseline (T18). Data was analysed with intention-to-treat principle and analysis of covariance. Exit interviews explored factors underlying exercise adherence. Results: There was no difference in baseline characteristics between groups. There was no change in maximum ankle DF in stance phase between T0 and T6 or in postural sway or PPPs (P>0.05). At T6, there were significant increases in Left (P=.001) and Right (P=.000) static ankle DF, left MTP-1 DF (P=.049) and FRT (P=.021). Changes were maintained at T18 (left and right ankle DF, p<0.01, right hallux DF p<0.01, FRT p<0.01). Intervention adherence was high (80%) and influenced by the physiotherapist, available time and perceived benefit. Conclusion: Ankle and MTP-1 mobilisations together are effective at increasing static measures of range. They may be useful for improving ankle, hallux joint mobility and anteroposterior stability limits in people with diabetes and neuropathy but not for reducing PPP or foot ulcer risk.