Evaluation of Plantar Foot Sensation, Balance, Physical Performance, and Fear of Movement in Substance Use Disorders

Relationship Between One-Leg Standing and Foot Sole Sensation Following Short-Term Immobilization of a Unilateral Lower Extremity

BACKGROUND

Several studies have suggested that approximately 10 hours of inactivity can reduce motor performance. Specifically, restricted lower limb movement may impair postural stability, subsequently increasing the incidence of falls. However, the relationship between postural sway and its related factors remains unclear. This study investigated the relationship between postural sway in the upright standing position and foot sole sensitivity after short-term immobilization.

METHODS

Healthy young adults were enrolled. Each participant's lower limb was immobilized for 10 hours using a soft bandage and a medical splint made from metal and soft urethane. The sway in the center of the pressure trajectory was measured before and after immobilization. Evaluation parameters included path length, mean velocity, and sway area. Foot sole sensitivity was assessed using an esthesiometer to measure two-point discrimination before cast application and immediately after cast removal.

RESULTS

After cast removal, total and anterior-posterior path lengths, mean velocity and sway area increased, whereas big toe sensitivity decreased. However, no significant correlations were observed among these factors.

CONCLUSIONS

Our results suggest that short-term movement restriction induces acute changes in center of pressure (COP) movement and foot sensitivity. However, the COP movement was not associated with foot sensation, indicating that another factor may contribute to postural sway after cast removal.

Perfusion, Stance and Plantar Pressure Asymmetries on the Human Foot in the Absence of Disease—A Pilot Study

Physiological perfusion asymmetries in the lower limb are known, although poorly understood, as are asymmetries reported in plantar pressure and stance. This preliminary study aims to explore potential relationships between perfusion and pressure variables in humans. A convenience sample of eight healthy individuals (25.25 ± 5.37 years old) of both sexes, was selected. Chosen variables were perfusion, plantar pressure, and stance. Perfusion was measured in both feet by laser Doppler flowmetry (LDF) and polarized light spectroscopy (PSp), and plantar pressure and stance obtained by a pressure plate. These were measured in baseline (Phase I) in a repeated squatting (Phase II), and in recovery (Phase III). A 95% confidence interval was adopted. Intraindividual significant perfusion asymmetries between both feet were detected by LDF in Phase I. These disappeared in Phase II and returned in Phase III. PSp did not detect any asymmetries. Plantar pressure was also asymmetric and differently distributed along both feet with no statistical significance except in the hindfoot. Significant correlations were found between BMI and mean Plantar Pressure in Phase I and Phase III, and an inverse correlation between LDF perfusion and Plantar Pressure in Phase I. These results seem to suggest an interesting direction for exploration and study of these asymmetries in the absence of disease.