Background:Stochastic resonance stimulation(SRS) transmits subsensory electrical Gaussian white noise into the body to enhance sensorimotor function.This therapy has improved static single leg balance in subjects with...Background:Stochastic resonance stimulation(SRS) transmits subsensory electrical Gaussian white noise into the body to enhance sensorimotor function.This therapy has improved static single leg balance in subjects with functional ankle instability.However,the effect of this stimulation on dynamic single leg balance is not known.Improvements in dynamic single leg balance with SRS may have implications For enhancing functional rehabilitation for ankle instability.Thus,the purpose of this study was to determine the effects of SRS on dynamic single leg balance in subjects with functional ankle instability. Methods:This study was an experimental research design and data were collected in a sports medicine research laboratory.Twelve subjects with functional ankle instability(69±15 kg;173±10 cm;21±2 years) reported a history of ankle sprains and instability at the ankle with physical activity.A single leg jump-landing test was used to assess dynamic balance.Subjects were required to jump between 50% and 55% of the maximal vertical jump height,land on a single leg atop a force plate,and stabilize as quickly as possible.Jump-landing tests were performed with and without SRS.Three trials were performed for each treatment condition(SRS and control).A randomized block design was used to determine test order.Anterior/posterior and medial/lateral time-to-stabilization were computed to assess dynamic balance.Lesser time indicated better stability.One-tailed paired samples t tests were used for analysis(α≤0.05). Results:SRS improved anterior/posterior time-to-stabilization(stochastic resonance = 1.32±0.31 s,control = 1.74±0.80 s,p = 0.03),but did not enhance medial/lateral time-to-stabilization(stochastic resonance = 1.95±0.40 s,control = 1.92±0.48 s,p = 0.07). Conclusion:Clinicians might use SRS to facilitate balance improvements with sagittal plane dynamic single leg balance exercises that patients may not be able to perform otherwise.展开更多
Background:Several case studies observed that the lateral ankle sprain resulted from a sudden increase in ankle inversion accompanied by internal rotation.However,without sufficient ankle kinetics and muscle activity ...Background:Several case studies observed that the lateral ankle sprain resulted from a sudden increase in ankle inversion accompanied by internal rotation.However,without sufficient ankle kinetics and muscle activity information in the literature,the detailed mechanism of ankle sprain is still unrevealed.The purpose of our case report is to present 2 accidental ankle giving way incidents for participants with chronic ankle instability(CAI)and compare to their normal trials with data of kinematics,kinetics,and electromyography(EMG).Case description:Two young female participants accidentally experienced the ankle giving way when landing on a 25°lateral-tilted force plate.3 D kinematics,kinetics,and muscle activity were recorded for the lower extremity.Qualitative comparisons were made between the giving way trials and normal trials for joint angles,angular velocities,moments,centers of pressure and EMG linear envelopes.Results:One participant’s giving way trial displayed increased ankle inversion and internal rotation angles in the pre-landing phase and at initial contact compared to her normal trials.Another participant’s giving way trial exhibited greater hip abduction angles and delayed activation of the peroneus longus muscle in the pre-landing phase versus her normal trials.Conclusion:A vulnerable ankle position(i.e.,more inverted and internally rotated),and a late activation of peroneus activity in the pre-landing phase could result in the ankle giving way or even sprains.A neutral ankle position and early activation of ankle evertors before landing may be helpful in preventing ankle sprains.展开更多
文摘Background:Stochastic resonance stimulation(SRS) transmits subsensory electrical Gaussian white noise into the body to enhance sensorimotor function.This therapy has improved static single leg balance in subjects with functional ankle instability.However,the effect of this stimulation on dynamic single leg balance is not known.Improvements in dynamic single leg balance with SRS may have implications For enhancing functional rehabilitation for ankle instability.Thus,the purpose of this study was to determine the effects of SRS on dynamic single leg balance in subjects with functional ankle instability. Methods:This study was an experimental research design and data were collected in a sports medicine research laboratory.Twelve subjects with functional ankle instability(69±15 kg;173±10 cm;21±2 years) reported a history of ankle sprains and instability at the ankle with physical activity.A single leg jump-landing test was used to assess dynamic balance.Subjects were required to jump between 50% and 55% of the maximal vertical jump height,land on a single leg atop a force plate,and stabilize as quickly as possible.Jump-landing tests were performed with and without SRS.Three trials were performed for each treatment condition(SRS and control).A randomized block design was used to determine test order.Anterior/posterior and medial/lateral time-to-stabilization were computed to assess dynamic balance.Lesser time indicated better stability.One-tailed paired samples t tests were used for analysis(α≤0.05). Results:SRS improved anterior/posterior time-to-stabilization(stochastic resonance = 1.32±0.31 s,control = 1.74±0.80 s,p = 0.03),but did not enhance medial/lateral time-to-stabilization(stochastic resonance = 1.95±0.40 s,control = 1.92±0.48 s,p = 0.07). Conclusion:Clinicians might use SRS to facilitate balance improvements with sagittal plane dynamic single leg balance exercises that patients may not be able to perform otherwise.
文摘Background:Several case studies observed that the lateral ankle sprain resulted from a sudden increase in ankle inversion accompanied by internal rotation.However,without sufficient ankle kinetics and muscle activity information in the literature,the detailed mechanism of ankle sprain is still unrevealed.The purpose of our case report is to present 2 accidental ankle giving way incidents for participants with chronic ankle instability(CAI)and compare to their normal trials with data of kinematics,kinetics,and electromyography(EMG).Case description:Two young female participants accidentally experienced the ankle giving way when landing on a 25°lateral-tilted force plate.3 D kinematics,kinetics,and muscle activity were recorded for the lower extremity.Qualitative comparisons were made between the giving way trials and normal trials for joint angles,angular velocities,moments,centers of pressure and EMG linear envelopes.Results:One participant’s giving way trial displayed increased ankle inversion and internal rotation angles in the pre-landing phase and at initial contact compared to her normal trials.Another participant’s giving way trial exhibited greater hip abduction angles and delayed activation of the peroneus longus muscle in the pre-landing phase versus her normal trials.Conclusion:A vulnerable ankle position(i.e.,more inverted and internally rotated),and a late activation of peroneus activity in the pre-landing phase could result in the ankle giving way or even sprains.A neutral ankle position and early activation of ankle evertors before landing may be helpful in preventing ankle sprains.
