Evaluating the effects of sedentary behaviour on plantar skin health in people with diabetes.

BACKGROUND: Diabetes-Related Foot Ulcers (DRFUs) are a common and devastating consequence of Diabetes Mellitus and are associated with high morbidity, mortality, social and economic costs. Whilst peak plantar pressures during gait are implicated cited as a major contributory factor, DRFU occurrence has also been associated with increased periods of sedentary behaviour. The present study was designed aimed to assess the effects of sitting postures on plantar tissue health. METHODS: After a period of acclimatisation, transcutaneous oxygen tensions (TCPO2) and inflammatory cytokines (IL-1α and IL-1RA) were measured at the dorsal and plantar aspects of the forefoot before, during and after a 20-min period of seated-weight-bearing in participants with diabetes (n = 11) and no diabetes (n = 10). Corresponding interface pressures at the plantar site were also measured. RESULTS: During weight-bearing, participants with diabetes showed increases in tissue ischaemia which were linearly correlated proportional to plantar pressures (Pearson's r = 0.81; p < 0.05). Within the healthy group, no such correlation was evident (p > 0.05). There were also significant increases in post seated weight-bearing values for ratio for IL-1α and IL-1RA, normalised to total protein, post seated weight-bearing in participants with diabetes compared to healthy controls. CONCLUSION: This study shows that prolonged sitting may be detrimental to plantar skin health. It highlights the need to further examine the effects of prolonged sitting in individuals, who may have a reduced tolerance to loading in the plantar skin and soft tissues.

Establishing a measurement array to assess tissue tolerance during loading representative of prosthetic use.

BACKGROUND: In the early stages of rehabilitation after primary amputation, residual limb soft tissues have not been mechanically conditioned to support load and are vulnerable to damage from prosthetic use. There is limited quantitative knowledge of skin and soft tissue response to prosthetic loading. METHODS: An in-vivo protocol was developed to establish suitable measures to assess tissue tolerance during loading representative of early prosthesis use. Ten participants without amputation one participant with trans-tibial amputation were recruited, and pressure applied to their calf in increments from 20 to 60 mmHg. Measurements were recorded at relevant skin sites including interface pressures, transcutaneous oxygen (TCPO2) and carbon dioxide (TCPCO2) tensions and inflammatory biomarkers. FINDINGS: At the maximum cuff pressure, mean interface pressures were between 66 and 74 mmHg, associated with decreased TCPO2 values. On the release of pressure, the ischaemic response was reversed. Significant upregulation (p < 0.05) in inflammatory biomarker IL-1α and its antagonist IL-1RA were observed at all sites immediately following loading. INTERPRETATION: The protocol was successful in applying representative prosthetic loads to lower limb tissues and monitoring the physiological response, both in terms of tissue ischemia and skin inflammation. Results indicated that the measurement approaches were sensitive to changes in interface conditions, offering a promising approach to monitor tissue status for people with amputation.