Static Postural Stability in Chronic Ankle Instability, an Ankle Sprain and Healthy Ankles

Abstract

To identify the single leg balance (SLB) test that discriminates among healthy, coper, and chronic ankle instability (CAI) groups and to determine effects of ankle muscles on the balance error scoring system (BESS) among the three populations. 60 subjects (20 per group) performed the SLB test with eyes open (EO) and eyes closed (EC). Normalized mean amplitude (NMA) of the tibia anterior (TA), fibularis longus (FL), and medial gastrocnemius (MG) muscles and BESS were measured while performing the SLB test. The coper group had a lower error score than the CAI group in the EC. NMA was greater in the CAI group compared to in the healthy and coper groups regardless of muscle type. NMA of the TA was less than the PL and MG regardless of the group in the EO. The CAI group demonstrated greater NMAs of the PL and MG than the healthy and coper groups in the EC. The CAI group demonstrated greater NMA of the PL and MG by compensating their ankle muscles in the EO and EC. BESS suggests that the coper group may have coping mechanisms to stabilize static postural control compared to the CAI group. The EC may be better to detect static postural instability in the CAI or coper group.

Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021

“…124,367 A systematic review by Rosen et al 376 found deficits in static and dynamic postural control in those with CAI. Similar findings were noted by other studies not included in the review by Rosen et al 22,89,105,116,138,167,205,239,250,258,260,352,376,392,405,485…”

Higher Leg and Trunk Muscle Activation during Balance Control in Copers versus People with Chronic Ankle Instability and Healthy Female Athletes

“…Similar to our results, one study showed lower MG EMG activity in individuals with CAI during single-leg stance when compared with healthy controls [ 31 ]. In contrast, one study reported greater MG EMG activity in the CAI group compared to the copers and healthy group [ 18 ]. In their study, Kwon et al reported that, during a single-leg balance test with eyes closed, the CAI group had higher fibularis longus and MG activity than the healthy and coper groups [ 18 ].…”

“…In contrast, one study reported greater MG EMG activity in the CAI group compared to the copers and healthy group [ 18 ]. In their study, Kwon et al reported that, during a single-leg balance test with eyes closed, the CAI group had higher fibularis longus and MG activity than the healthy and coper groups [ 18 ]. Difference in testing protocols can be designated as the source of this discrepancy, with the Kwon study conducting balance tests in participants with their eyes closed.…”

“…Difference in testing protocols can be designated as the source of this discrepancy, with the Kwon study conducting balance tests in participants with their eyes closed. The lack of visual input has been known to disrupt balance [ 18 ], thus requiring more muscular contribution to achieve stability compared to having visual feedback [ 32 ], as individuals would rely more on proprioception feedback mechanism for balance which leads to altered muscle activation. However, difference in muscular EMG activation is not limited to the ankle, and can also reach the upper segments.…”

“…Recent studies reported that CAI individuals showed significantly less peroneus longus activity and shorter peroneus longus latency compared to the coper group in dynamic tasks [ 16 , 17 ]. In a study by Kwon et al, it was reported that muscle activity in the CAI group is different compared to the healthy and coper groups during single-leg balance with eyes closed [ 18 ]. Muscle strategies used during dynamic balance tasks are phase dependent between CAI, copers, and healthy individuals.…”