Balance control in the elderly: do Masters athletes show more efficient balance responses than healthy older adults?

Resting-state Functional Connectivity of the Motor and Cognitive Areas is Preserved in Masters Athletes

Aging is characterized by a decline in physical and cognitive functions, often resulting in decreased quality of life. Physical activity has been suggested to potentially slow down various aspects of the aging process, a theory that has been supported by studies of Masters Athletes (MA). For example, MA usually have better cognitive and physical functions than age-matched sedentary and healthy older adults (OA), making them a valuable model to gain insights into mechanisms that promote physical and cognitive function with aging. The purpose of this study was to identify differences in resting-state functional connectivity (rs-FC) of motor and cognitive regions between MA and OA and determine if these differences in the resting brain are associated with differences in cognitive and physical performance between groups. Fifteen MA (9 males) and 12 age-matched OA (six males) were included. rs-FC images were compared to identify significant between-groups differences in brain connectivity. There was higher connectivity between the cognitive and motor networks for the OA group, whereas the MA group had stronger connectivity between different regions within the same network, both for the cognitive and the motor networks. These results are in line with the literature suggesting that aging reduces the segregation between functional networks and causes regions within the same network to be less strongly connected. High-level physical activity practiced by the MA most likely contributes to attenuating aging-related changes in brain functional connectivity, preserving clearer boundaries between different functional networks, which may ultimately favor maintenance of efficient cognitive and sensorimotor processing.

Postural balance ability and vertical jumping performance in female veteran volleyball athletes and non-athletes

Lifetime participation in sports is associated with improved components of physical conditioning. The main purpose was to cross-sectionally investigate postural balance and vertical jumping performance in athletes with different histories of sports participation and secondarily to examine the restriction of vision on balance ability. A final aim was to investigate possible associations between balance and jumping performance. We hypothesized higher balance and jumping performance in active veteran volleyball athletes compared to retired athletes and non-athletes, suggesting a positive effect of continuous systematic training in active veteran athletes. We also hypothesized greater negative effect of vision removal on balance in the veteran compared to non-athletes due to athletes' stronger reliance on visual information. Eighty-one healthy middle-aged women (mean (standard deviation) 50 (5) years) were assigned to three experimental groups, a retired (n = 39, recreationally active former athletes), an active (n = 27, training 2days/week x 1.5 h/session) veteran volleyball athletes' and a control group (n = 15, sedentary participants). Participants completed an assessment of single-legged quiet stance trials with either left or right leg with eyes open while standing barefoot on a force plate and two-legged trials with both eyes open or closed. They also executed a protocol of countermovement jumps. Statistical analyses included univariate and full factorial ANOVAs with group and vision as fixed and repeated-measures factors and simple linear regression analysis. In the single-legged balance task, solely the mediolateral sway range was greater for the active (p < 0.001) and retired athletes (p < 0.001) compared to non-athletes, whereas in the two-legged stance, no differences among groups were found (p > 0.05). Restriction of vision deteriorated balance performance similarly in the three groups as a significant vision effect was found for path length (p < 0.001), anteroposterior (p < 0.001) and mediolateral sway (p < 0.05). The active and retired athletes had significantly (p < 0.001) greater height, mean and maximal power in countermovement jump compared to non-athletes. Results showed weak associations (average R² = 9.5%) of balance with jumping performance only in the veteran volleyball athletes' group. Overall, the findings showed that retired volleyball athletes exhibited similar balance ability and vertical jumping performance as the active ones, suggesting a positive impact of prior experience in systematic training.

What Do We Know About the Value of Sport for Older Adults? A Scoping Review

Issues relating to older adults in sport are ongoing topics of interest among sport scientists; however, our knowledge on how older athletes have been studied is incomplete, which has implications for understanding the comprehensiveness of this evidence base. This scoping review aimed to provide an overview of how sport and older adults have been studied since the first World Masters Games. Data on research topics, research methods, sport-specific information, and demographic information on older athletes were collected and reviewed. Results suggest older athletes who are White, male, and competitive athletes have largely been the focus of research. In addition, results highlight an alarming number of unreported data related to the demographics of athlete samples. As a result, the well-documented benefits of sport may reflect a homogenous group of older adults, limiting our overall understanding of aging and sport and the value of this research for developing evidence-informed policy.

Physical active lifestyle promotes static and dynamic balance performance in young and older adults

Although regular physical activity exposure leads to positive postural balance control (PBC) adaptations, few studies investigated its effects, or the one of inactivity, on PBC in populations of different age groups. Thus, this study investigated the impact of a physically active lifestyle on static and dynamic PBC in young and older adults. Thirty-five young physically active subjects (YA), 20 young sedentary subjects (YS), 16 physically active older adults (OA), and 15 sedentary older adults (OS) underwent a static and a dynamic PBC assessment. A force platform and an instrumented proprioceptive board were employed to measure the center of pressure (COP) trajectory and the anteroposterior oscillations, respectively. In static conditions, no significant differences were detected among groups considering the overall postural balance performance represented by the area of confidence ellipse values. Conversely, the YA highlighted a higher efficiency (i.e., lower sway path mean velocity) in PBC maintenance compared to the other groups (YA vs OA: p = 0.0057, Cohen's d = 0.94; YA vs OS p = 0.043, d = 1.07; YA vs YS p = 0.08, d = 0.67). OS exhibited an overall worse performance in dynamic conditions than YA and YS. Surprisingly, no differences were found between YS and OA for all the static and dynamic parameters considered. In conclusion, our results suggest that a physically active lifestyle may promote static and dynamic balance performance in young and older adults, thus with potentially positive effects on the age-related decline of postural balance performance. Dynamic PBC assessment seems more sensitive in detecting differences between groups than the static evaluation.

Isokinetic Muscle Strength and Postural Sway of Recreationally Active Older Adults vs. Master Road Runners

Trunk muscle strength and control is an important prerequisite for everyday activities among elderly people decreasing the predisposition to falls. High levels of physical exercise performed by older athletes could offer benefits to core/trunk muscle strength and postural control compared with recreational physical activities and among elderly people with lower levels of physical activity. The present study aimed to compare trunk muscle strength and postural control of older running athletes vs. older physically active adults. Participants were master road runners (RUN, n = 15, six women, 64.3 ± 3.6 years) and physically active elderly (control group, CON, n = 15, six women, 65.4 ± 5.0 years) people that were submitted to the evaluations: esthesiometer, posturography (force plate), and isokinetic test (Biodex dynamometer) of trunk muscle extension and flexion. RUN presented higher values for relative peak torque of trunk extensor muscles at 60°/s (p = 0.046) and 180°/s (p = 0.007) and relative average power during trunk extension at 60°/s (p = 0.008) and 180°/s (p = 0.004) compared to CON. CON had a higher medial-lateral oscillation speed of the center of pressure in the stable condition with eyes closed (p = 0.004) compared to RUN. RUN presented higher isokinetic torque of extensor trunk muscles and better postural control than CON. This supposedly could help with postural control and balance and contribute to the prevention of falls among the elderly. The practice of running systematically by master athletes may partially explained our findings.

Comparison of balance performance between masters Olympic weightlifters and runners

Balance disorders are a common problem among older adults that greatly increase susceptibility for falls and fractures. Aerobically trained older (masters) athletes tend to exhibit superior balance abilities compared to that of healthy age-matched counterparts. Olympic weightlifting involves tremendous power production and motor skill coordination throughout the body which may prompt unique sensory information acquisition and integration adaptations. The purpose of this investigation was to compare a modified clinical test of sensory interaction and balance performance between middle-aged (~40-60 years) masters Olympic weightlifters (OWL, n = 48) and runners (RUN, n = 42). Average mediolateral center of pressure velocity (MLCPV) was computed during completion of 2 double leg trials (30-s) completed on firm (FI) and foam (FO) surfaces with eyes open (EO) and eyes closed (EC). While there were no significant differences between the groups for either the EO-FI (P = .143, d = 0.34) or EO-FO (P = .209, d = 0.26), the OWL demonstrated significantly better balance (lower MLCPV) than the RUN for both the EC-FI (P = .009, d = 0.59) and EC-FO (P = .001, d = 0.70). The most salient result of this investigation was the identification of better balance performance by the OWL, particularly when visual inputs were unavailable (ie, EC), compared to the RUN. These results suggest that Olympic weightlifting may provide a superior training stimulus for somatosensory and vestibular function compared to running in middle-aged adults, a benefit that may help to offset archetypal age-related balance deficits.

Differences in postural sway among healthy adults are associated with the ability to perform steady contractions with leg muscles

Upright standing involves small displacements of the center of mass about the base of support. These displacements are often quantified by measuring various kinematic features of the center-of-pressure trajectory. The plantar flexors have often been identified as the key muscles for the control of these displacements; however, studies have suggested that the hip abductor and adductors may also be important. The purpose of our study was to determine the association between the force capabilities of selected leg muscles and sway-area rate across four balance conditions in young (25 ± 4 years; 12/19 women) and older adults (71 ± 5 years; 5/19 women). Due to the marked overlap in sway-area rate between the two age groups, the data were collapsed, and individuals were assigned to groups of low- and high-sway area rates based on a k-medoid cluster analysis. The number of participants assigned to each group varied across balance conditions and a subset of older adults was always included in the low-sway group for each balance condition. The most consistent explanatory variable for the variance in sway-area rate was force control of the hip abductors and ankle dorsiflexors as indicated by the magnitude of the normalized force fluctuations (force steadiness) during a submaximal isometric contraction. The explanatory power of the regression models varied across conditions, thereby identifying specific balance conditions that should be examined further in future studies of postural control.

Does severity of motor impairment affect reactive adaptation and fall-risk in chronic stroke survivors?

Background

A single-session of slip-perturbation training has shown to induce long-term fall risk reduction in older adults. Considering the spectrum of motor impairments and deficits in reactive balance after a cortical stroke, we aimed to determine if chronic stroke survivors could acquire and retain reactive adaptations to large slip-like perturbations and if these adaptations were dependent on severity of motor impairment.

Methods

Twenty-six chronic stroke participants were categorized into high and low-functioning groups based on their Chedoke-McMaster-Assessment scores. All participants received a pre-training, slip-like stance perturbation at level-III (highest intensity/acceleration) followed by 11 perturbations at a lower intensity (level-II). If in early phase, participants experienced > 3/5 falls, they were trained at a still lower intensity (level-I). Post-training, immediate scaling and short-term retention at 3 weeks post-training was examined. Perturbation outcome and post-slip center-of-mass (COM) stability was analyzed.

Results

On the pre-training trial, 60% of high and 100% of low-functioning participants fell. High-functioning group tolerated and adapted at training-intensity level-II but low-functioning group were trained at level-I (all had > 3 falls on level-II). At respective training intensities, both groups significantly lowered fall incidence from 1st through 11th trials, with improved post-slip stability and anterior shift in COM position, resulting from increased compensatory step length. Both groups demonstrated immediate scaling and short-term retention of the acquired stability control.

Conclusion

Chronic stroke survivors are able to acquire and retain adaptive reactive balance skills to reduce fall risk. Although similar adaptation was demonstrated by both groups, the low-functioning group might require greater dosage with gradual increment in training intensity.

Feasibility of whole body vibration during intensive chemotherapy in patients with hematological malignancies - a randomized controlled pilot study

BACKGROUND

Hospitalized cancer patients undergoing intensive or high-dose chemotherapy often experience a considerable decline in functional performance associated with the increased risk of adverse health events. Exercises, particularly resistance-based exercises that may counteract this decline are restricted by therapy-related side effects. Since whole body vibration (WBV) is known to efficiently stimulate the neuromuscular system without significantly raising blood pressure, we hypothesize that especially WBV is particularly feasible even during intensive or high-dose chemotherapy (primary endpoint) and thus induces beneficial functional adaptations.

METHODS

Twenty hospitalized patients with hematological malignancies scheduled for intensive or high-dose chemotherapy were randomly allocated to an intervention group (IG) undergoing WBV, or an active control group (CG) cycling. Feasibility was determined by comparing the IG's and CG's training compliance. Furthermore, to assess feasibility, WBV-induced changes in chemotherapy-related side effects, blood pressure, and heart rate immediately after exercising were documented. To assess patients' functional performance, we measured jump height (cm), the duration (sec) of performing the chair rising- (CRT) and timed-up-and-go test (TUG), maximum power output during jumping and CRT (watt/kg) as well as sway path (mm) during balance tasks.

RESULTS

Training compliance was similar between groups (IG: median 62%, range 39-77; CG: 67%, 58-100; p = 0.315). Moreover, we observed neither the IG's reported side effects worsening, nor any increase in blood pressure after WBV. IG's jump height (+ 2.3 cm, 95%CI 0.1-4.4, p = 0.028) and TUG performance (- 1.3 s, 95%CI -2.53 - -0.65, p = 0.027) improved significantly, while sway paths in semi-tandem stance were augmented after the intervention (eyes open: + 60 mm, 95%CI 2-236, p = 0.046; eyes closed: + 88 mm, 95%CI 49-214, p = 0.028). The CG's performances did not change over time. Maximum power output during CMJ and CRT and time during CRT did not change.

CONCLUSION

Our study is the first proving the feasibility of WBV during intensive/high-dose chemotherapy of hospitalized cancer patients. Additionally, WBV-induced neuromuscular adaptations resulted in functional benefits relevant to patients' autonomy. We believe that WBV can be implemented as an alternative training method during intensive chemotherapy, although the relative benefit compared to conventional resistance training requires more evaluation in future studies.

TRIAL REGISTRATION

German Register of Clinical Trials No.: DRKS00004338 , prospectively registered on 11/30/2012.

Postural Stability During Standing Balance and Sit-to-Stand in Master Athlete Runners Compared With Nonathletic Old and Young Adults

The aim of this study was to compare postural sway during a series of static balancing tasks and during five chair rises between healthy young (mean [SEM], age 26 [1] years), healthy old (age 67 [1] years) and master athlete runners (age 67 [1] years; competing and training for the previous 51 [5] years) using the Microsoft Kinect One. The healthy old had more sway than the healthy young in all balance tasks. The master athletes had similar sway to young athletes during two-leg balancing and one-leg standing with eyes open. When balancing on one leg with eyes closed, both the healthy old and the master athletes had around 17-fold more sway than the young athletes. The healthy old and master athletes also had less anterio-posterior movement during chair rising compared with young athletes. These results suggest that masters runners are not spared from the age-associated decline in postural stability and may benefit from specific balance training.

Intensity and generalization of treadmill slip training: High or low, progressive increase or decrease?

The purpose of this study was to investigate the efficacy of different treadmill slip training protocols on the transfer of reactive and proactive control of center of mass stability to a novel, over-ground slip. Four training protocols were investigated: high-intensity (HI; acceleration of all treadmill slips=12m/s(2)), low-intensity (LO; acceleration of all treadmill slips=6m/s(2)), progressively increasing intensity (INCR; acceleration of treadmill slips increasing from 6m/s(2) to 12m/s(2) over the course of training), and progressively decreasing intensity (DECR; acceleration of treadmill slips decreasing from 12m/s(2) to 6m/s(2) over the course of training). From a pool of 36 young subjects, nine were randomly assigned to each training protocol (HI, LO, INCR, and DECR). In each protocol, subjects underwent a series of 24 treadmill slips before they experienced a novel slip during over-ground walking. Measures from these subjects were compared across groups and to data from control subjects (CTRL, n=9) who had experienced a novel over-ground slip without treadmill training as part of a previous experiment. The results showed that treadmill slip training improved balance control on over-ground slip and had a larger effect on subjects׳ reactive control of stability (44.3%) than on proactive control (27.1%) in comparison with the CTRL group. HI yielded stronger generalization than LO, while INCR was only marginally better than DECR. Finally, the group means of stability displayed a clear ascending order from CTRL, LO, DECR, INCR, to HI.

Sports activities are reflected in the local stability and regularity of body sway: older ice-skaters have better postural control than inactive elderly

With age postural control deteriorates and increases the risk for falls. Recent research has suggested that in contrast to persons with superior balance control (dancer's athletes), with pathology and aging, predictability and regularity of sway patterns increase and stability decreases implying a less adaptive form of postural control. The aim of the present study was to determine, whether patterns of body sway of elderly (N=13) who practice a sport which challenges postural control (ice speed-skating), are more similar to that of young subjects (N=10) than to that of inactive elderly (N=10). Trunk patterns were measured with a tri-axial accelerometer. Data were recorded during quiet upright stance with (1) eyes open, (2) limited vision, and (3) while performing a dual task. Anterior-posterior and medio-lateral acceleration time-series were analyzed. Differences in postural control were quantified in terms of the magnitude of the acceleration (root mean square), the smoothness (mean power frequency), the predictability (sample entropy) and the local stability (largest Lyapunov exponent). Postural control of ice-skating elderly differed from that of sedentary elderly. As anticipated, postural control of the ice-skating elderly was similar to that of young adults. For anterior-posterior accelerations, the skating elderly and the younger subjects had significant higher stability and lower regularity than the non-skating elderly in all tasks. These results imply that sport activities such as ice-skating are beneficial for elderly people. It might, at least partly, counteract the age related changes in postural control.

Balance control during lateral load transfers over a slippery surface

Few studies have measured balance control during manual material handling, and even fewer with environmental cofactors. This study examined the effect of different surface frictions during a stationary manual material handling task. Thirty-six healthy participants completed 180° lateral transfer tasks of a load over high- and low-friction surfaces (μ = 0.86 and μ = 0.16, respectively). Balance measures, stance kinematics and lower extremity muscle activities were measured. Success during the novel slippery surface dichotomised our population, allowing us to investigate beneficial techniques to lateral load transfers over the slippery surface. Stance width reduction by 8 cm and 15° of additional external foot rotation towards the load were used to counter the imbalance created by the slippery surface. There was no clear alteration to lower extremity muscular control to adapt to a slippery surface. Changes in stance seemed to be used successfully to counter a slippery surface during lateral load transfers. STATEMENT OF RELEVANCE: Industries requiring manual material handling where slippery conditions are potentially present have a noticeable increase in injuries. This study suggests stance configuration, more so than any other measure of balance control, differentiates vulnerability to imbalance during material handling over a slippery surface.

Effects of an unstable shoe construction on balance in women aged over 50 years

BACKGROUND

Shoes with an unstable sole construction are commonly used as a therapeutic tool by physiotherapists and are widely available from shoe and sporting goods retailers. The aim of this study was to investigate the effects of using an unstable shoe (Masai Barefoot Technology) on standing balance, reactive balance and stability limits.

METHODS

Thirty-one subjects agreed to participate in the study and underwent balance tests on three different occasions. After test occasion one (baseline) 20 subjects received Masai Barefoot Technology shoes and were requested to wear them as much as possible for the remaining eight weeks of the study. Three specific balance tests were administered on each test occasion using a Pro Balance Master (NeuroCom International Inc., Oregon, USA). Tests included; a modified sensory organization test, reactive balance test and limits of stability test.

FINDINGS

Subjects in the intervention group significantly improved their performance on elements of all three tests however results on these variables were not demonstrated to be significantly better than the control group. No significant differences were observed across testing occasions in the control group.

INTERPRETATION

Results from the present study suggest that, for this group of individuals, use of unstable footwear may improve certain aspects of balance.