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The purpose of this study was twofold: (a) to compare postural control between a group of young female gymnasts ( n = 15; age: 11.2 ± 1.9 years) and non-trained peers ( n = 15; age: 10.9 ± 2.0 years), and (b) to investigate the effect of an 8-week whole body exercise intervention program on postural control in young female gymnasts. Postural control was assessed by recording center of pressure (CoP) movements during unipedal quiet stance. Velocity and amplitude of CoP movement in anterior-posterior (AP) and medial-lateral (ML) directions were considered. In addition to common trial-averaged CoP outcomes, we also considered the transient behavior of CoP movements, by calculating relative differences between the 1st and 2nd, and the 1st and 3rd 10-s intervals within the whole trial (DIF_21 and DIF_31, respectively). The gymnast group had lower total CoP velocity (Cohen's d = 0.97) and AP amplitude (Cohen's d = 0.85), compared to their non-trained peers. The gymnasts also had lower CoP AP amplitude DIF21 (Cohen's d = 0.73), with almost constant values across all intervals. After the training ML CoP velocity was reduced for 13.12% (Cohen's d = 0.60), while ML CoP amplitude increased (Cohen's d = -0.89).

Background: The previous studies have investigated causes of and risk factors for falls and impairment of functional capability in older adults. However, the biomechanical factors involved in functional performance and postural control, and the contribution of hip muscles, are still unknown., Aims: The aim of the present study was to verify the association between the muscle function of hip abductors and adductors and static and dynamic balance, in a narrow base of support, in community-dwelling older adults., Methods: Eighty-one older adults, including both women and men, were evaluated. Tandem gait and single-leg stance were used to assess static and dynamic balance, and an isokinetic dynamometer was used to analyze muscle function (peak torque and rate of torque development according to body weight). Data were analyzed by a multivariate linear regression test without adjustment and with adjustment using two models: adjustment I (sex) and adjustment II (age)., Results: There was a statistically significant association between peak torque of abductor in single-leg stance and tandem gait speed. The PT of hip adductors contributed to static balance performance, in a narrow base of support from the unadjusted data and from the adjusted data by sex., Conclusion: The findings of the present study are relevant, because if deficits in balance and functionality in older adults can be linked to a decline in maximum muscle strength of hip abductors, this parameter can be treated to maintain independence in older adults for as long as possible.

Objectives: This study investigated the changes in ankle active range of motion (AROM) and performance on the Balance Error Scoring System (BESS) in cases in which no tape, placebo taping or ankle balance taping (ABT) with kinesiology tape was used., Design: Randomized cross-over trial., Setting: University laboratory., Participants: Fifteen physically active individuals (7 men, 8 women)., Main Outcome Measurements: Postural control was assessed based on performances on the BESS. Active ankle flexibility was assessed by measuring the ankle AROM of both ankles under each taping condition in a random order at 1-week intervals., Results: The ankle AROM among the taping conditions were not significantly different. There were no significant differences in the error scores of single-leg and tandem stances on a firm surface among the taping conditions. Compared to those obtained in the absence of taping, the error scores of the single-leg and tandem stances on a foam surface were significantly lower with ABT, but they did not significantly differ from the placebo taping scores., Conclusions: This study showed that ABT with kinesiology tape immediately improved postural control on unstable surfaces without changes in ankle AROM., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The purpose of this study was to determine the natural foot position and to quantify the effect of foot position on balance performance during single-leg stance. Forty healthy subjects participated in this study (age, 18 to 32 years; 24 female). Subjects were asked to perform single-leg balance trials on a balance force plate in their self-selected and four predetermined foot positions with their eyes open and closed. Sway distance, area and velocity were computed for each trial. There was significant interactions between visual conditions and foot position for all sway parameters (P<.001). With the eyes closed, sway parameters were greatest for the self-selected foot position compared to the other foot positions (P<.005). No differences in sway parameters between foot positions were detected for the eyes-open condition. Sway distance, area and velocity were 94%, 400% and 89% greater, respectively, for the eyes-closed than the eyes-open condition. Self-selected foot placement did not produce the most stable single-leg stance. The results of this study indicate that foot position is not important for protocols for assessing balance or for rehabilitation exercises using eyes-open conditions and that assessment protocols and rehabilitation exercises should clearly specify the foot position when using eyes-closed protocols., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

With the loss of a lower limb, amputees lack the active muscle empowered control of the ankle that is important for balance control. We examined single-leg stance on prosthesis vs. sound limb balancing on narrow ridges in transtibial amputees. When balancing on the prosthetic limb, the lateral displacement of the center of pressure was reduced and was compensated by an increase in counter-rotation. We show that single-leg stance on a prosthetic limb can be compared to balancing on a narrow ridge. Standing on a prosthetic limb involves the same balance mechanisms as balancing on narrow ridges of 40-mm to 20-mm width. Yet, the ability to balance on a narrow ridge with the sound limb was only a weak predictor for an amputee's ability to stand on the prosthetic limb. Balancing in single-leg stance on a prosthetic limb is not a common activity. The ability to compensate with the sound limb may therefore be functionally more important than the ability to stay in dynamic balance on the prosthetic limb., (Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.)

The goal of this study was to evaluate muscle activation onset times (MAOT) of both legs during a transition task from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament injured (ACLI) (n=15) and non-injured control subjects (n=15) with eyes open and eyes closed. Significantly delayed MAOT were found in the ACLI group compared to the control group for vastus lateralis, vastus medialis obliquus, hamstrings medial, hamstrings lateral, tibialis anterior, peroneus longus and gastrocnemius in both vision conditions, for gluteus maximus and gluteus medius with eyes open and for tensor fascia latae with eyes closed. Within the ACLI group, delayed MAOT of tibialis anterior with eyes open and gastrocnemius with eyes closed were found in the injured leg compared to the non-injured leg. All other muscles were not significantly different between legs. In conclusion, the ACLI group showed delayed MAOT not only around the knee, but also at the hip and ankle muscles compared to the non-injured control group. No differences between both legs of the ACLI group were found, except for tibialis anterior and gastrocnemius. These findings indirectly support including central nervous system re-education training to target the underlying mechanisms of these altered MAOT after ACL injury., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The goal of this study was to evaluate postural stability during the transition from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament reconstructed (ACLR) (n=20) and non-injured control subjects (n=20). All ACLR subjects had fully returned to their pre-injury sport participation. Both groups were similar for age, gender, height, weight, body mass index and activity level. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from DLS to SLS in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the SLS phase was significantly increased in the ACLR group compared to the control group in the eyes closed condition (P=.001). No significant different postural stability outcomes were found between the operated and non-operated legs. In conclusion, the ACLR group showed postural stability deficits, indicating that these persons may have a decreased ability to stabilize their body after the internal postural perturbation created by the transition from DLS to SLS. The non-operated leg may not be the best reference when evaluating postural stability of the operated leg after ACLR, as no differences were found between legs., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: An anterior cruciate ligament injury may lead to deteriorations in postural stability. The goal of this study was to evaluate postural stability during the transition from double-leg stance to single-leg stance of both legs in anterior cruciate ligament injured subjects and non-injured control subjects with a standardized methodology., Methods: Fifteen control subjects and 15 anterior cruciate ligament injured subjects (time after injury: mean (SD)=1.4 (0.7) months) participated in the study. Both groups were similar for age, gender, height, weight and body mass index. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Movement speed was standardized., Findings: The center of pressure displacement after a new stability point was reached during the single-leg stance phase was significantly increased in the anterior cruciate ligament injured group compared to the control group in the eyes closed condition (P<.001). No significant different postural stability outcomes were found between both legs within both groups (P>.05). No significant differences were found during the transition itself (P>.05)., Interpretation: The anterior cruciate ligament injured group showed postural stability deficits during the single-leg stance phase compared to the non-injured control group in the eyes closed condition. Using the non-injured leg as a normal reference when evaluating postural stability of the injured leg may lead to misinterpretations, as no significant differences were found between the injured and non-injured leg of the anterior cruciate ligament injured group., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Balance deteriorates with age and fall related injuries are often linked to long-term disability and loss of independence in older adults. This study focuses on the task of establishing single leg stance, which requires the ability to shift the center of mass onto the supporting leg., Methods: Fifteen younger adults and eight older adults participated in the study. Subjects performed a step with self-selected step length onto the force plate to establish a single leg stance (SLS) on their dominant leg. The first four seconds of SLS were analyzed to investigate age related temporal dependencies of sway area, sway velocity, anterior-posterior sway, and medio-lateral sway., Findings: Younger adults show a rapid decrease of sway area, anterior-posterior sway, medio-lateral sway, and sway velocity within the first four seconds while older adults show elevated initial values in anterior-posterior sway and sway velocity and less decrease over time., Interpretation: Older adults have not only diminished initial sway, but also less ability to control sway during the initial phase of single leg stance. The early phase of single leg stance is rather dynamic in older adults compared to younger adults who maintain their balance after three seconds with small adjustments., (Published by Elsevier Ltd.)

The single-leg stance test is included in the FUNfitness (FF) screening for Special Olympic athletes to determine if balance education and/or referrals are needed. There are limited data regarding the use of the single-leg stance test for people with intellectual disabilities. Data were collected for this prospective study as part of the FF screens during the 2018 Special Olympics summer games. Each athlete completed the SLS test on the right (R) and left (L) lower extremity (LE), with eyes opened (SLS-EO) and closed (SLS-EC), and asked if they had fallen in the past year. A total of 178 athletes completed the test. Data analysis revealed a weak relationship between falls and SLS-EO (R LE rs = −0.170 and L LE rs = −0.185) and SLS-EC (R LE rs = −0.169 and L LE rs = −0.187), all of which were significant (p<.05). Sensitivity and specificity of the SLS-EO were low for both the R LE (74.5% and 42.2%, respectively) and L LE (74.5% and 42.7%, respectively). Sensitivity rose slightly with SLS-EC (R LE = 80.9% and L LE = 89.1%), while specificity decreased (R LE = 22.9% and L LE = 25.2%). The positive predictive values for SLS-EO and SLS-EC ranged from 27.3% to 31.8%. The SLS test demonstrated poor accuracy in identifying fallers in SO athletes with area under the curve values ranging from 0.610 to 0.623. These results indicate that the SLS test, or cutoff scores used, may not be the most appropriate for this population. [ABSTRACT FROM AUTHOR]

Introduction. The aim of the study was to determine the differences in the quality of postural control between two female rhythmic gymnasts with different training experience during the performance of balance exercises. In rhythmic gymnastics, the same balance exercises are performed by novice and elite gymnasts. Balance exercises involving standing on the toes of one leg with the free leg raised in different positions are considered to be extreme forms of exercise in terms of the postural balance abilities required. In coaching practice, it is important to have tools which facilitate the objective assessment of the process of maintaining balance in such exercises. Material and methods.The study involved two female rhythmic gymnasts: a younger one (age = 8 years and training experience = 4 years) and an older one (age = 21 years and training experience = 14 years). The athletes performed three balance exercises standing on a Kistler platform: the split with hand support (lateral balance), the ring with hand support, and the back split without hand support (balance on the whole foot). The parameters describing the quality of postural control used in the current analysis were the range and velocity of COP displacements in the anterior-posterior and medial-lateral directions. Results. Postural control in the balance exercises in the younger rhythmic gymnast was characterised by almost two times greater COP displacements in the anterior-posterior direction and more rapid than that of the older gymnast. COP displacements in the medial-lateral direction in all the exercises described did not differentiate the subjects. In the back split without hand support, the older athlete showed greater variability of postural control with smaller COP displacement and velocity than the younger gymnast. Conclusion. Gymnastics training should include exercises strengthening the muscles acting on the ankle and hip joints, which could improve the stability of these joints during the performance of difficult balance exercises. Improving the stabilising function of these muscles helps to minimise anterior-posterior movements in these joints. [ABSTRACT FROM AUTHOR]

Time to stabilization (TTS) has been introduced as a method to analyze dynamic postural stability during jump and landing tasks, but has also been applied during the transition task from double-leg stance (DLS) to single-leg stance (SLS). However, the application of the originally described TTS technique during the latter task has some important limitations. The first goal of this study was to present an adapted version of the TTS technique to provide an effective alternative method to better analyze postural stability during the transition from DLS to SLS. The second goal was to study the influence of pathology and different speeds on postural stability outcomes. Fifteen healthy control subjects and 15 subjects with chronic ankle instability (CAI) performed the transition task on their preferred speed and as fast as possible, with eyes open and with eyes closed. Subjects with CAI performed the transition significantly slower when moving at their preferred speed with eyes closed. The time subjects needed to reach a new stability point was not discriminative between groups and largely dependent on movement speed. However, the amount of sway after this new stability point was significantly increased in the CAI group and when eyes were closed. The results of this study suggest that subjects with CAI have a decreased ability to overcome the postural perturbation created by the voluntary movement f r om DLS to SLS. Focusing only on TTS during the transition from DLS to SLS may lead at least in some cases to misinterpretations when assessing postural stability. [ABSTRACT FROM AUTHOR]