Orthoses are designed to assist a malaligned foot in adapting to the environment and reduce the frequency of injury. Literature is divided on the benefits of orthotics insoles for postural stability. The current study was conducted to determine the effect of prefabricated orthotic arch supports on postural stabilization. Twelve healthy young adults participated in this study and were tested with and without prefabricated orthotics. Different variables were computed from movement of center of pressure (COP) during orthotic use as suggested in the literature. The mean position of COP was significantly shifted forward and toward the dominant side. Neither the COP movement nor the velocity changes following the use of orthotics revealed significant differences. Mediolateral range of COP movement and the 95% confidence circle area of sway was significantly reduced (P = .022 and 0.048 respectively), but changes in 95% confidence circle and ellipse areas of fractal dimension were not significant (P = .053 and P = .057 respectively). In conclusion, orthotic insoles significantly improved postural sway initially by reducing mediolateral range of postural sway and 95% confidence circle area of sway at the cost of increased fractal dimension area variables and power.
Hamid Bateni, Gina Leno, Rebeca Manjarres, Bailey Ouellette, and Mark Wolber
Previous research has demonstrated that localized leg muscle fatigue induced by lower extremity exercises (e.g., squat jumps, sprints, and treadmill running) has an adverse effect on postural stability.
To assess the effect of cardiovascular fatigue induced by upper extremity exercise on postural stability.
Fourteen healthy young adults between the ages of 22 and 30 years (7 male and 7 female).
Participants performed an exercise protocol on an upper-body ergometer to induce cardiovascular fatigue.
Main Outcome Measures:
Postural sway, represented by center of pressure excursion, during bilateral standing in two different foot positions.
In a tandem standing position, mediolateral mean distance, root mean square distance, resultant power, and centroidal frequency increased signifcantly after inducement of cardiovascular fatigue.
Cardiovascular fatigue adversely affects postural stability.