The effect of unilateral balance training on postural control of the contralateral limb

Balance improvements in healthy subjects are independent to postural strategies involved in the training

BACKGROUND

Adequate postural strategies have a pivotal role in ensuring balance during the performance of daily or sport activities. These strategies are responsible for the management of center of mass kinematics and depend on the magnitude of perturbations and posture assumed by a subject.

RESEARCH QUESTION

Are there differences in postural performance after a standardized balance training performed in sitting versus standing posture in healthy subjects? Does a standardized unilateral balance training with the dominant or non-dominant limb improve balance on trained and untrained limbs in healthy subjects?

METHODS

Seventy-five healthy subjects reporting a right-leg dominance were randomized into a Sitting, Standing, Dominant, Non-dominant or Control groups. In the Experiment 1, Sitting group performed a 3-week balance training in seated posture, whereas Standing group performed the same training in bipedal stance. In the Experiment 2, Dominant and Non-dominant groups underwent a 3-week standardized unilateral balance training on the dominant and non-dominant limbs, respectively. Control group underwent no intervention and was included in both experiments. Dynamic (Lower Quarter Y-Balance Test with the dominant and non-dominant limbs and trunk and lower limb 3D kinematics) and static (center of pressure kinematics in bipedal and bilateral single-limb stance) balance were assessed before and after the training, and at 4 weeks follow-up.

RESULTS

A standardized balance training in sitting or standing posture improved balance without between-group differences, while a unilateral balance training with the dominant or non-dominant limb improved postural stability on the trained and untrained limbs. Trunk and lower limb joints range of motion increased independently to their involvement in the training.

SIGNIFICANCE

These results may allow clinicians to plan effective balance interventions even when a training in standing posture is not possible or in subjects with restricted limb weight-bearing.

The Effect of Contralateral Knee Neuromuscular Exercises on Static and Dynamic Balance, Knee Function, and Pain in Athletes Who Underwent Anterior Cruciate Ligament Reconstruction: A Single-Blind Randomized Controlled Trial

CONTEXT

Contralateral training in the early stages after surgery can improve the balance of the reconstructed knee, which is impaired following anterior cruciate ligament reconstruction (ACLR). However, little is known about the neuromuscular cross exercise after ACLR.

OBJECTIVE

To investigate the effects of an 8-week cross exercise on balance and function of the reconstructed knee following ACLR.

DESIGN

A single-blind randomized clinical trial.

PARTICIPANTS

Thirty athletic males who underwent ACLR were randomly divided into intervention (n = 15) and control groups (n = 15).

INTERVENTION

The intervention and control groups received a routine physiotherapy program. In addition, the intervention group performed neuromuscular exercises on the nonoperated limb.

OUTCOME MEASURES

Before and 9 weeks after ACLR, dynamic and static balance, function, and pain in the reconstructed knee were measured by Star Excursion Balance Test (SEBT), stork balance stand test, balance error scoring system (BESS), Lysholm questionnaire, and visual analog scale. Data were analyzed by SPSS using 2-independent sample t test, paired t test, and analysis of covariance.

RESULTS

Between-group comparison showed that, contralateral knee neuromuscular exercises significantly increased in the reaching distance in SEBT in the anterior (P < .001), posterior (P < .001), posteromedial (P = .010), and posterolateral directions (P = .007), decreased the number of errors in 4 stance positions of BESS including single stance on the firm (P ≤ .001) and foam surface (P ≤ .001), and tandem stance on the firm (P = .028) and foam surface (P ≤ .001). It also increased the time of standing of the stork stand test (P = .044) and decreased the pain intensity (P = .014).

CONCLUSION

Neuromuscular exercise of the nonsurgical knee could improve the dynamic and static balance, and pain in the early stages following ACLR in the surgical leg. These findings may be potentially valuable for current rehabilitation protocols.

Single Leg Balance Training: A Systematic Review

Single leg balance training promotes significant increments in balance control, but previous reviews on balance control have not analyzed this form of balance training. Accordingly, we aimed to review the single leg balance training literature to better understand the effects of applying this training to healthy individuals. We searched five databases-PubMed, EMBASE, Scopus, Lilacs, and Scielo-with the following inclusion criteria: (a) peer-reviewed articles published in English; (b) analysis of adult participants who had no musculoskeletal injuries or diseases that might impair balance control; and (c) use of methods containing at least a pre-test, exclusive single leg balance training, and a post-test assessment. We included 13 articles meeting these criteria and found that single leg balance training protocols were effective in inducing balance control gains in either single- or multiple-session training and with or without progression of difficulty. Balance control gains were achieved with different amounts of training, ranging from a single short session of 10 minutes to multiple sessions totaling as much as 390 min of unipedal balance time. Generalization of balance gains to untrained tasks and cross-education between legs from single leg balance training were consistent across studies. We concluded that single leg balance training can be used in various contexts to improve balance performance in healthy individuals. These results extend knowledge of expected outcomes from this form of training and aid single leg balance exercise prescription regarding volume, frequency, and potential progressions.

Acute effects of a single unilateral balance training session on ipsi- and contralateral balance performance in healthy young adults

Objective

While there is evidence on the short-term effects of unilateral balance training (BT) on bipedal balance performance, less is known on the acute effects of unilateral BT on unilateral (i.e., ipsi- and contralateral) balance performance. Thus, the present study examined the acute effects of a single unilateral BT session conducted with the non-dominant, left leg or the dominant, right leg on ipsilateral (i.e. retention) and contralateral (i.e., inter-limb transfer) balance performance in healthy young adults (N = 28).

Results

Irrespective of practice condition, significant improvements (p < 0.001, d = 1.27) in balance performance following a single session of unilateral BT were observed for both legs. Further, significant performance differences at the pretest (p = 0.002, d = 0.44) to the detriment of the non-dominant, left leg diminished immediately and 30 min after the single unilateral BT session but occurred again 24 h following training (p = 0.030, d = 0.36). These findings indicate that a single session of unilateral BT is effective to reduced side-to-side differences in balance performance, but this impact is only temporary.

The role of the dominant leg while assessing balance performance. A systematic review and meta-analysis

BACKGROUND

Good balance is a pre-requisite for various activities of daily life and sports. Physiotherapists thus regularly assess and train patient's balance capacities. In order to interpret the test results of unilateral balance tests, a comparison with normative data is common. In patients who had an injury or a surgery, the performance of the injured leg is often compared with performance of the non-injured leg. Nevertheless, it remains unclear if unilateral balance performance differs between the dominant and non- dominant legs. If so, this should take into consideration when interpreting test results.

RESEARCH QUESTION

This meta-analysis summarized the current evidence to determine if the balance performance of healthy adults was influenced by the leg's dominance.

METHODS

Articles were searched in PubMed, CINAHL, Cochrane and Embase. Data from studies meeting the pre-defined inclusion criteria were extracted in a standardized form. A meta-analysis was conducted using a random effect model.

RESULTS

Forty-six studies were included. Their data were allocated in 7 categories of balance tests. Significant differences between the dominant and the non-dominant legs were not found in any of the categories (surface stable, eyes open: -0.04, 95 % CI -0.12 to 0.05, surface stable eyes closed: -0.06, 95 % CI -0.22 to 0.11, surface unstable, eyes open: -0.15, 95 % CI -0.38 to 0.07, surface unstable, eyes closed: -0.06, 95 % CI -0.27 to 0.15, BESS (Balance Error Scoring System): 0.03, 95 % CI -1.09 to 1.14, SEBT (Star Excursion Balance Test)/YBT (Y Balance Test): 0.06, 95 % CI -0.04 to 0.16, jump: 0.04, 95 % CI -0.28 to 0.36).

SIGNIFICANCE

Results indicate that balance performance is not influenced by the leg's dominance. This means that performances of both legs can be used as reference. Evidence is strong for the one leg stance. However, future studies are needed to confirm our results for stabilization tasks after a jump landing.

Acute Effects of Increased Joint Mobilization Treatment Duration on Ankle Function and Dynamic Postural Control in Female Athletes With Chronic Ankle Instability

Background:

Chronic ankle instability (CAI) is linked to mechanical and functional insufficiencies. Joint mobilization is purported to be effective at treating these deficits.

Purpose:

To examine the effect of different treatment durations of a grade IV anterior-to-posterior ankle joint mobilization on weightbearing dorsiflexion range of motion (WB-DFROM), posterior talar glide (PG), and dynamic postural control in individuals with CAI.

Study Design:

Controlled laboratory study.

Methods:

A total of 48 female athletes (mean age, 22.8 ± 4.8 years) with unilateral CAI participated in this study. Participants were randomly assigned to 1 of 3 treatment conditions: 30 seconds, 60 seconds, and 120 seconds. Treatment was provided to the injured limb on 3 separate occasions 48 hours apart and consisted of a Maitland grade IV anterior-to-posterior talar joint mobilization based on the participant’s initial group assignment. WB-DFROM; PG; and the anterior (ANT), posteromedial (PM), and posterolateral (PL) reach directions of the Star Excursion Balance Test were measured bilaterally before and after each treatment. The uninjured limb acted as a control. Data were analyzed using 2-way mixed-model analyses of variance, and effect sizes were calculated through use of Hedges g.

Results:

Significant differences were detected after all treatment sessions for all outcome measures (P ≤ .001) and between treatment groups after sessions 1, 2, and 3 for all outcome measures (P ≤ .001). Effect sizes were very large or huge for all treatment groups for WB-DFROM, PG, and ANT reach direction. Substantial variation was found in effect sizes for PM and PL measures.

Conclusion:

Accessory mobilization is an effective treatment to induce acute changes in ankle motion and dynamic postural control in patients with CAI, with longer treatment durations conferring greater improvements.

Clinical Relevance:

This study adds clarity to the use of joint mobilization treatments and will add to the current clinical practice strategy for patients with CAI.

Cross-Education Related to the Ipsilateral Limb Activity on Monopedal Postural Control of the Contralateral Limb: A Review

Cross-education is the effect whereby the ipsilateral limb training generates contralateral effects as part of motor tasks requiring strength and skills. However, it is not yet known if cross-education applies to postural control which could be essential as part of human motricity. Hence, this review addresses the possible effects of acute and chronic unilateral exercises (i.e., fatiguing exercises and regularly repeated/training exercises, respectively) on the contralateral monopedal postural control. Evidence suggests that fatiguing exercises disturb the contralateral monopedal postural control. This disturbance emanates from spinal and supra-spinal alterations which provokes changes to the motor function of the contralateral limb and degrades its postural control. Unilateral training produces cross-education related to postural control, especially when it includes balance exercises, but this remains to be tested when it includes resistance exercises. Mechanistic explanations are proposed to explain how neurophysiological changes operate in the disturbance or improvement of the contralateral monopedal postural control after unilateral fatiguing exercises or training exercises (respectively) of the lower-limb.

3D Analysis of Upper Limbs Motion during Rehabilitation Exercises Using the KinectTM Sensor: Development, Laboratory Validation and Clinical Application

Optoelectronic devices are the gold standard for 3D evaluation in clinics, but due to the complexity of this kind of hardware and the lack of access for patients, affordable, transportable, and easy-to-use systems must be developed to be largely used in daily clinics. The Kinect^TM sensor has various advantages compared to optoelectronic devices, such as its price and transportability. However, it also has some limitations: (in)accuracy of the skeleton detection and tracking as well as the limited amount of available points, which makes 3D evaluation impossible. To overcome these limitations, a novel method has been developed to perform 3D evaluation of the upper limbs. This system is coupled to rehabilitation exercises, allowing functional evaluation while performing physical rehabilitation. To validate this new approach, a two-step method was used. The first step was a laboratory validation where the results obtained with the Kinect^TM were compared with the results obtained with an optoelectronic device; 40 healthy young adults participated in this first part. The second step was to determine the clinical relevance of this kind of measurement. Results of the healthy subjects were compared with a group of 22 elderly adults and a group of 10 chronic stroke patients to determine if different patterns could be observed. The new methodology and the different steps of the validations are presented in this paper.

Effects of Reach Balance Exercise on Toe Grip Strength and Balance in College Basketball Players

Objective

This study was conducted to clarify the ground reaction force exerted on the foot during athletic movements and to demonstrate the effects of reach balance training (RB-T) on toe grip strength as an injury prevention exercise.

Methods

RB-T was undertaken for 2 weeks by 11 male college basketball players and 22 healthy male college students (including 10 participants in the control group). The vertical ground reaction forces during athletic movements were measured using ground reaction force meters. Before and after RB-T intervention, toe grip strength was measured with a toe grip strength meter, and distances of the center of pressure (COP) to the center of the foot during movement were measured using a three-dimensional motion analyzer.

Results

The vertical ground reaction force during athletic movement was highest during take-off and decreased in the following order: single-leg front landing, single-leg lateral landing, and turning. The toe grip strength of the BT group and the T group increased after RB-T intervention. For the BT group, RB-T also tended to decrease the COP lateral distance on turning in the dominant leg and the COP front distance on turning and take-off in both legs.

Conclusion

RB-T could improve the toe grip strength and stabilize the COP position.