Single-leg Balance Research Articles

Weighting of visual and auditory inputs in dancers with and without previous ankle injury

Elite dance requires highly controlled balance performance in dynamic visual and auditory environments characterized by the use of stage lighting and music. Perturbing visual input is known to influence balance in dancers, but the effects of sounds have not been clearly established. Ankle inversion injuries are common in dancers and may also play a role in dancers' ability to respond to sensory perturbations. The aims of this study were to identify changes in static balance in response to visual or auditory perturbation in elite collegiate dancers with and without a history of ankle injury, and to describe coupling of measurements obtained from the waist and head during balance. Thirty-seven dancers: 22 controls and 15 with a history of ankle sprain, performed single-leg balance under static and dynamic visual and auditory conditions. Dancers demonstrated increased waist sway when viewing a dynamic visual scene and when presented with moving sounds and increased head sway with dynamic visuals. These results did not vary by history of ankle sprain. While dancers appear to dampen the impact of waist sway on head motion during single leg stance, even highly trained dancers may experience challenges controlling balance under perturbing visual and auditory conditions like those present during stage performance.

The effects of kinesiophobia on postural control with chronic ankle instability

BackgroundPatients with chronic ankle instability (CAI) often experience injury-related fear following ankle injuries, a condition known as kinesiophobia. Little research has investigated the impact of kinesiophobia in patients with CAI. Research questionHow does kinesiophobia impact the static and dynamic balance of individuals with CAI? MethodsFifty patients with CAI were divided into 2 subgroups based on their responses to the Tampa Scale of Kinesiophobia: 25 with kinesiophobia (CAI-K) and 25 without kinesiophobia (CAI-N). These groups were compared to 20 control participants. All participants performed a single-leg balance test with eyes open (EO) and eyes closed (EC). They also performed the Y-balance test (YBT) with EO. Romberg ratios were calculated as EC/EO and used for statistical analysis. ResultsNo differences in static balance with EO and EC were found among three groups. However, the CAI-K group displayed a higher Romberg ratio in the mediolateral direction during static balance than both CAI-N and control groups. Additionally, both CAI-K and CAI-N groups displayed higher Romberg ratio in the anterior–posterior than controls. During YBT, the CAI-K group showed reduced reach distance in the anterior direction than CAI-N and control groups. SignificanceThe CAI-K group relies more on visual feedback during static balance in the mediolateral direction than CAI-N and control groups. Furthermore, the CAI-K group displayed less anterior reach distance during YBT compared to the CAI-N and control groups. Clinicians should consider both psychological and physical factors when designing rehabilitation programs.

Kadınlarda Dinamik Denge Üzerinde Kuadriseps Kas Aktivasyonu ile Q Açısı Arasındaki İlişki

Introduction: Lower extremity biomechanics affects the relationship between Q angle, quadriceps muscle activation and the balance.
 Objectiveː The aim was to examine the relationship between Q angle and quadriceps muscle activation on dynamic balance position in women. 
 Materials and Methodsː Forty women were included in the study. The muscle activation of the quadriceps during dynamic balance in a single leg stance was recorded. A tape measure was used to measure Q angle, surface electromyography was used to assess muscle activation, the Flamingo Balance Test was used to assess static balance, the TechnoBody PK 200WL computerized balance device was used to assess dynamic balance, and the Short Form Musculoskeletal Assessment was used to assess functionality.
 Resultsː There was a statistically significant positive correlation between the Q angle standing and supine position and vastus medialis muscle activation respectively, (r=0.35, p=0,02; r=0.40, p=0.01). There was a statistically significant positive correlation between the perimeter length and Q angle in standing/supine position respectively, (r=0.33, p=0.04; r=0.32, p=0.04). Area gap percentage and Q angle standing (r=0.89, p=0.02), supine position Q angle values (r=0.63, p=0.03) were positively correlated.
 Conclusionː If vastus medialis is more strengthened, Q angle would be more normalized, so quadriceps muscle strengthening exercises are helpful for the normalization of the Q angle. Also, when the Q angle is normalized, a single leg balance would be revealed.

OA02 Hip pain in the young and active patient? Don’t forget FAI

OA02 Hip pain in the young and active patient? Don’t forget FAI

The influence of a preworkout energy drink (C4) on lower limb neuromuscular activation in healthy young adults

Energy drinks (Edrinks) have a plethora of ingredients for the same objective, a burst of energy and improving mood among others. However, there are various Edrink brands with diverse ingredients and slightly different purposes, such as the C4 drink which is a pre-workout. This ingredient variation can provoke different neuromuscular balance and gait adaptations. Recent studies suggest that some ingredients in Edrinks can aid in muscle fatigue in lower limb musculature. To investigate the lower limb neuromuscular modification after edink (C4) consumption. Ten participants (1 male and 9 females) partaken in the study (age of 23.4 (+/- 2.95). Neuromuscular activation of leg musculature was measured during a single-legged balance test on a firm and foam surface, pre and post edrink. Balance tests were designed to engage diverse areas of the balance systems (visual, proprioceptive and vestibular) while studying the adaptations in lower limb muscles such as tibialis anterior and gastrocnemius. The main outcome of this study showed a trend towards greater onset, faster TP, and slower decay for leg muscles after edrink consumption. It seems C4 beverage provokes a faster and prolonged recruitment of the leg muscles. Future studies should look into the postural adaptations after the said drink.

Lower limb muscle strength and balance in older adults with a distal radius fracture: a systematic review

BackgroundDistal radius fractures are common fractures in older adults and associated with increased risk of future functional decline and hip fracture. Whether lower limb muscle strength and balance are impaired in this patient population is uncertain. To help inform rehabilitation requirements, this systematic review aimed to compare lower limb muscle strength and balance between older adults with a distal radius fracture with matched controls, and to synthesise lower limb muscle strength and balance outcomes in older adults with a distal radius fracture.MethodsWe searched Embase, MEDLINE, and CINAHL (1990 to 25 May 2022) for randomised and non-randomised controlled clinical trials and observational studies that measured lower limb muscle strength and/or balance using instrumented measurements or validated tests, in adults aged ≥ 50 years enrolled within one year after distal radius fracture. We appraised included observational studies using a modified Newcastle-Ottawa Scale and included randomised controlled trials using the Cochrane risk-of-bias tool. Due to the clinical and methodological heterogeneity in included studies, we synthesised results narratively in tables and text.ResultsNineteen studies (10 case-control studies, five case series, and four randomised controlled trials) of variable methodological quality and including 1835 participants (96% women, mean age 55–73 years, median sample size 82) were included. Twelve included studies (63%) assessed strength using 10 different methods with knee extension strength most commonly assessed (6/12 (50%) studies). Five included case-control studies (50%) assessed lower limb strength. Cases demonstrated impaired strength during functional tests (two studies), but knee extension strength assessment findings were conflicting (three studies). Eighteen included studies (95%) assessed balance using 14 different methods. Single leg balance was most commonly assessed (6/18 (33%) studies). All case-control studies assessed balance with inconsistent findings.ConclusionCompared to controls, there is some evidence that older adults with a distal radius fracture have impaired lower limb muscle strength and balance. A cautious interpretation is required due to inconsistent findings across studies and/or outcome measures. Heterogeneity in control participants’ characteristics, study design, study quality, and assessment methods limited synthesis of results. Robust case-control and/or prospective observational studies are needed.RegistrationInternational prospective register of systematic reviews (date of registration: 02 July 2020, registration identifier: CRD42020196274).

Changes in functional outcomes in people with high-energy ankle trauma after the use of the ReAktiv Posterior Dynamic Element™ orthosis and a rehabilitation program: A case series.

The aim of this study was to examine lower-limb function in 2 patients that received a ReAktiv Posterior Dynamic Element™ (PDE) orthosis and 6-week rehabilitation program after a high-energy trauma injury to the lower limb. Lower-limb function was assessed using the lower extremity functional score, walking performance through the 2-minute walk test, and dynamic mobility and balance through the single-leg balance, timed stair ascent, and the 4-square step test. A 6-week physiotherapy-led rehabilitation program was also implemented. Data showed improvements in lower extremity function, walking performance, mobility, and balance measures after 8 weeks of wearing the ReAktiv PDE™ orthosis and completion of the rehabilitation program. The ReAktiv PDE™ orthosis combined with a lower-limb rehabilitation program shows potential as a treatment option to improve lower-limb function and walking performance and return sufferers of high-energy trauma injury to functional levels seen in healthy cohorts.

Tai Chi for fall prevention and balance improvement in older adults: a systematic review and meta-analysis of randomized controlled trials.

As the population ages, the health of older adults is becoming a public health concern. Falls are a significant threat to their health due to weakened balance. This study aims to investigate the beneficial effects of Tai Chi on fall prevention and balance improvement in older adults. We conducted a systematic review and meta-analysis of randomized controlled trials related to Tai Chi, falls, and balance ability, searching PubMed, Embase, and Cochrane Library databases from their establishment until December 31, 2022. Two independent reviewers performed the search, screening of results, extraction of relevant data, and assessment of study quality. This study followed the PRISMA guidelines for systematic review and meta-analysis. Totally 24 RCTs were included for meta-analysis, and the results showed that Tai Chi can effectively reduce the risk of falls in older adults (RR: 0.76, 95% CI: 0.71 to 0.82) and decrease the number of falls (MD [95% CI]: -0.26 [-0.39, -0.13]). Tai Chi can also improve the balance ability of older adults, such as the timed up and go test (MD [95% CI]: -0.69 [-1.09, -0.29]) and the functional reach test (MD [95% CI]: 2.69 [1.14, 4.24]), as well as other balance tests such as single-leg balance test, Berg balance scale, and gait speed (p < 0.05). Subgroup analysis showed that Tai Chi is effective for both healthy older adults and those at high risk of falls (p < 0.001), and its effectiveness increases with the duration and frequency of exercise. In addition, the effect of Yang-style Tai Chi is better than that of Sun-style Tai Chi. Tai Chi is an effective exercise for preventing falls and improving balance ability in older adults, whether they are healthy or at high risk of falling. The effectiveness of Tai Chi increases with exercise time and frequency. Yang-style Tai Chi is more effective than Sun-style Tai Chi. https://clinicaltrials.gov/, identifier CRD42022354594.

Segmental extracellular-to-intracellular water resistance ratio and physical function in older adults

ObjectivesThis study aimed to investigate the association between whole-body (WB), arm, and leg extracellular-to-intracellular water resistance (Recw/Ricw) ratios and various physical functions of each segment and muscle mass using segmental multifrequency bioelectrical impedance analysis. MethodsIn total, 988 community-dwelling older adults were included in the analysis. Physical function was assessed using hand grip, 5-repetition sit-to-stand, 5-m habitual walk, Timed Up and Go, and single-leg balance with eyes open tests. Each segmental Recw/Ricw ratio and muscle mass were assessed at 5 and 250 kHz resistances using a segmental multifrequency bioelectrical impedance analysis device. Pearson's correlation between the segmental Recw/Ricw ratio and muscle mass and physical function was calculated, and the difference in correlation coefficients was tested using Bonferroni correction. Multiple linear regression analysis was conducted using physical function as the dependent variable and the segmental Recw/Ricw ratio as the independent variable, adjusting for sex, age, body mass index, and segmental muscle mass. ResultsWB and leg Recw/Ricw ratios were significantly positively correlated with good hand grip performance, gait speed, mobility, balance, and standing power (p < 0.05), after adjusting for sex, age, body mass index, and muscle mass. Furthermore, the leg Recw/Ricw ratio was positively associated with lower extremity physical function compared with WB and arm Recw/Ricw ratios and muscle mass (p < 0.01). Conversely, WB muscle mass was more strongly related to grip strength than WB, arm, and leg Recw/Ricw ratios (p < 0.01). ConclusionsThe Recw/Ricw ratio is useful for identifying older adults with worse physical function. The Recw/Ricw ratio allows for easy and timely screening of older adults with worse physical function in clinical settings.

Delivering a Home-Based Exercise Program to Youth With Osteogenesis Imperfecta: Protocol for a Comparative-Approach Study

Background Osteogenesis imperfecta (OI) is a rare bone fragility disorder associated with muscle weakness. Individuals with OI may therefore benefit from exercise interventions aiming to improve muscle and bone strength. Given the rarity of OI, many patients do not have access to exercise specialists who are familiar with the disorder. As such, telemedicine, the provision of health care through technology to provide care at a distance, may be well suited for this population. Objective The main objectives are (1) to investigate the feasibility and cost-effectiveness of 2 telemedicine approaches for the delivery of an exercise intervention for youth with OI and (2) to assess the impact of the exercise intervention on muscle function and cardiopulmonary fitness in youth with OI. Methods Patients with OI type I (the mildest form of OI; n=12, aged 12-16 years) from a pediatric orthopedic tertiary hospital will be randomized to receive a 12-week remote exercise intervention in either (1) a supervised group (n=6), monitored every session, or (2) a follow-up group (n=6), receiving monthly progress update appointments. Participants will undergo the following pre- and postintervention evaluations: sit-to-stand test, push-up test, sit-up test, single-legged balance test, and a heel-rise test. Both groups will be given the same 12-week exercise regimen, which includes cardiovascular, resistance, and flexibility training. For each exercise training session involving the supervised group, a kinesiologist will provide instructions to participants through live video sessions using a teleconferencing application. On the other hand, the follow-up group will discuss their progress with the kinesiologist every 4 weeks over a teleconferencing video call. Feasibility will be assessed by recruitment, adherence, and completion rates. A cost-effectiveness analysis of both approaches will be computed. Changes in muscle function and cardiopulmonary fitness will be examined between the 2 groups, pre- and postintervention. Results It is anticipated that the supervised group will have higher adherence and completion rates compared to the follow-up group, which may be associated with greater physiological benefits; however, it may not be as cost-effective compared to the follow-up approach. Conclusions By determining the most feasible telemedicine approach, this study may serve as a basis for providing increased access to specialized adjunct therapies for individuals with rare disorders. International Registered Report Identifier (IRRID) PRR1-10.2196/40262

PS10 Can an aerobic exercise intervention for patients with psoriasis improve health outcomes and support lifestyle behaviour change?

Abstract Patients with psoriasis do not exercise to the extent recommended for cardiovascular health, due to significant disease-specific barriers, which may augment their increased risk of CVD and metabolic syndrome. Therefore, we developed a bespoke, evidenced-based exercise programme for patients with psoriasis, hypothesizing that it may have utility in the management of psoriasis. Eight patients with psoriasis (32.5 ± 12.02 years old, BMI 26.7 ± 3.3 kg m-2) completed a 20-week physical activity intervention. The first 10 weeks of the intervention comprised two walking sessions per week. Each session was of 1h duration and led by a sports-scientist for small-groups of patients with psoriasis. The volume of exercise per session was calculated so that participants would incrementally progress to heart-healthy levels of exercise over the programme. During weeks 10–20 of the programme, participants engaged in independent activities. Warm-ups, pre-exercise stretching, and cool-downs were incorporated into each of the sports-scientist led sessions. Step counts were recorded using a Newfeel Onwalk 900 pedometer throughout the study. Measurements at pre-, mid-, and post-intervention endpoints (week 0, 10 and 20) included assessment of (i) psoriasis: Psoriasis Area and Severity (PASI); Physicians Global Assessment (PGA); (ii) quality of life: Dermatology Life Quality Index (DLQI), Short Form 36 (SF-36); and (iii) cardiometabolic disease/risk – pulse wave velocity (PWV); blood pressure (BP); body weight and BMI. In addition, cardiorespiratory fitness (CRF) was assessed by: 30-s sit-to-stand (30STS); timed up and go (TUG); single leg balance (SLB); static body-weight wall-squat (SBWS); and step count. Recruitment to the study is ongoing. We observed a significant reduction in both Psoriasis Area and Severity Index and systolic BP at the weeks 10 and 20 timepoints (P &amp;lt; 0.05). We also observed a statistically significant improvement in the SF-36 mental health domain between the weeks 10 and 20 timepoints (P = 0.035). The CRF statistically significantly improved across the duration of the study, with a statistically significant improvement in exercise performance, as evidenced by 30STS, TUG and pedometer step counts at week 10 (P &amp;lt; 0.05), SLB between baseline and week 20 (P = 0.043) and SBWS performance across all timepoints. Exercise induces health benefits, including reduced skin inflammation and systolic BP, and increased CRF, and may improve some aspects of quality of life in those with psoriasis. The impact of lifestyle on psoriasis warrants further investigation. Our data suggest that exercise could represent an adjuvant therapy in the future management of psoriasis.

Electromyographic and Stabilometric Analysis of the Static and Dynamic "Standing Bird Dog" Exercise.

(1) Background: The "bird dog" exercise is considered one of the most effective therapeutic exercises for lumbopelvic rehabilitation and the prevention and treatment of low back pain. The "standing bird dog" (SBD) exercise, executed in a single-leg stance, constitutes a natural and challenging variation in the "bird dog"; nevertheless, this exercise has not yet been investigated. This study provides a stabilometric and electromyographic analysis of the SBD performed in static and dynamic conditions and in ipsilateral and contralateral variations; (2) Methods: A time-synchronized motion capture system, wireless electromyography sensors, and triaxial force platform were used to analyze the selected SBD exercises; (3) Results: In dynamic conditions, the gluteus maximum, multifidus, lumbar erector spinae, and gluteus medius reached a mean activation level higher than in the static condition, with peak activation levels of 80%, 60%, 55%, and a 45% maximum voluntary isometric contraction, respectively. In the static condition, balance control was more challenging in the mediolateral compared to the anteroposterior direction. In the dynamic condition, the balance challenge was higher in the anteroposterior direction and higher than the static condition in both directions; (4) Conclusions: The SBD was proved to be effective for strengthening the hip and lumbar extensor muscles and provided a powerful challenge to single-leg balance control in both mediolateral and anteroposterior directions.

The Effects of Mental Health Conditions and Sex on Standing Balance in Undergraduate Students

Abstract&#x0D; &#x0D; Purpose: Balance is important to human functioning and is required to carry out daily tasks. Studies have shown that females have better balance than males. Mental health conditions are prevalent in undergraduate students, and we are unsure of their impact on balance. The purpose of this study was to investigate if sex or a mental health condition (attention deficit hyperactivity disorder (ADHD), generalized anxiety disorder, depression, or a combination of these conditions) are associated with changes in single-leg balance performance in undergraduate university students. Additionally, a secondary purpose was to investigate the relationship between weekly physical activity and balance performance. &#x0D; Method: Sixty-nine (36 female, and 33 male) undergraduate students at Western University participated in this study. Participants completed three standardized assessment questionnaires to identify individuals with scores consistent with ADHD, anxiety, and depression. Individuals with more than one of these conditions formed the multiple condition group. The control group consisted of individuals that did not show scores that were consistent with a mental health condition. A Leisure Time Exercise Questionnaire was completed to quantify weekly physical activity, and a personal activity score was calculated for each participant. Finally, three 20-second single-leg standing balance trials were performed on a force plate, and balance performance was quantified using the path length. A two-way ANOVA assessed the relationship between sex and mental health conditions on standing balance.&#x0D; Results: There was no statistically significant interaction between sex and mental health conditions (P=0.15). However, path length in the multiple condition group was significantly higher than the control group (P &lt; 0.05). In terms of activity scores and balance, there were no apparent trends between males and females nor between the different mental health groups. Conclusion: Our results indicate that sex was not associated with significant differences in balance performance, and that students with multiple mental health conditions had significantly worse single-leg balance performance than controls. Additionally, weekly physical activity was not associated with better balance performance. These results could be valuable for clinicians when diagnosing balance related conditions, such as concussions.&#x0D; &#x0D; Key Terms: Mental health, balance, single-leg, physical activity&#x0D;

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.

Acute Neuromuscular Alterations of Ankle Evertors Induced by Short Trail Running: Sex-Related Considerations.

Abstract Ravier, G, Dury, J, Grevillot, J, Girard, B, Bouzigon, R, and Michel, F. Acute neuromuscular alterations of ankle evertors induced by short trail running: sex-related considerations. J Strength Cond Res 37(10): 2008–2015, 2023—This study investigated the exercise-induced effects on the neuromuscular function of ankle evertors, balance control associated with trail running, and sex-related interactions. Fourteen male and 14 female medium-level runners completed a 16-km (400 D+) course. At rest and immediately after running, maximal voluntary isometric contraction (MVC) and rate of force development (RFD) for knee extension and ankle eversion, electromyographic (EMG) activity of peroneus muscles during MVC plateau (EMG) and the first 200 ms (EMG200), ankle angular velocity ( INV) during 20 weight-bearing inversion movements, and balance control during destabilizing single-leg task were evaluated. Repeated measures ANOVA-revealed changes in knee and ankle MVC (ankle: P = 0.0004, −12%) and RFD (ankle: P &lt; 0.0001, −19%), EMG (P &lt; 0.0001, −17%), EMG200 (P &lt; 0.0001, −19%), and ankle INV (P &lt; 0.0001, +35%) in response to trail running. Single-leg balance was not impaired. Sex-related differences were observed in EMG and EMG200 with higher values in men than in women. MVC and RFD were greater in men when expressed in absolute values, but not different relative to body mass. Single-leg balance and ankle INV did not differ between men and women. Finally, none of these variables showed any sex-related difference when considering pre-exercise to postexercise changes. This study demonstrated impairment in neuromuscular function of evertor muscles and ability in braking inversion in response to trail running. Sex-related differences were observed in neuromuscular activity but not in fatigability. These data suggest that coaches might implement strength exercises specifically designed for ankle lateral stability into their training program.

Strength and Balance in Recreational Golfers and Non-Golfers Aged 65-79Years in Community Settings.

Inactive older adults tend to have decreased strength and balance compared with their more active peers. Playing golf has the potential to improve strength and balance in older adults. The aim of the study was to compare the strength and balance of recreational golfers with non-golfers, aged 65-79years. Grip strength, single leg balance, and Y Balance Test (YBT) were assessed. Golfers (n = 57) had significantly (right, p = .042; left, p = .047) higher maximal grip strength, than non-golfers (n = 17). Single leg stance times were significantly longer in golfers (right, p = .021; left, p = .001). Normalized YBT reach distances were significantly greater for golfers than non-golfers for composite, posteromedial, and posterolateral directions on both right and left legs. Playing golf appears to be associated with better grip and both static and dynamic balance in 65-79 year olds, indicating that a study of the effects of playing golf is warranted through a larger, fully powered, longitudinal study.

Normative values for grip strength, gait speed, timed up and go, single leg balance, and chair rise derived from the Canadian longitudinal study on ageing.

decreased muscle strength and physical function often precede disability, nursing home admission, home care use and mortality in older adults. Normative values for commonly used physical performance-based tests are not widely available for older adults but are required for clinicians and researchers to easily identify individuals with low performance. to develop normative values for grip strength, gait speed, timed up and go, single-leg balance and five-repetition chair rise tests in a large population-based sample of Canadians aged 45-85years. baseline data (2011-2015) from the Canadian Longitudinal Study on Ageing was used to estimate age- and sex-specific normative values for each of the physical tests. Participants were without disability or mobility limitation (no assistance with activities of daily living or use of mobility devices). of the 25,470 participants eligible for the analyses 48.6% (n = 12,369) were female with a mean age of 58.6 ± 9.5years. Sex-specific 5th, 10th, 20th, 50th, 80th, 90th and 95th percentile values for each physical performance-based test were estimated. Cross-validation (n = 100 repetitions) with a 30% holdout sample was used to evaluate model fit. the normative values developed in this paper can be used in clinical and research settings to identify individuals with low performance relative to their peers of the same age and sex. Interventions targeting these at-risk individuals including physical activity can prevent or delay mobility disability and the resulting cascade of increasing care requirements, health care costs and mortality.

Lower Quarter Y-Balance Test Anterior Reach Asymmetry and Noncontact Lower Limb Injury in Subelite Young Male Soccer Players With Different Training Experiences

Poor single-leg balance performance is associated with an increased risk of sustaining lower limb injuries in team sports. However, it is unclear whether this relationship is modified by the level of training experience (years of training experience). The objective of the present study was to evaluate whether soccer players’ single-leg balance performance is related to lower limb injuries in noncontact situations with different levels of training experience. Subelite young male soccer players performed the Lower Quarter Y-Balance Test with the dominant and the nondominant leg at the beginning of the preseason. Due to COVID-19 rules, the occurrence of lower limb injuries during the second half of the competitive season was documented. The odds of injury were calculated based on a previously reported Lower Quarter Y-Balance Test cut-off score for side-to-side anterior reach difference (≥4 cm). Twelve soccer players sustained a lower leg injury in noncontact situations. Only four of them had an anterior reach difference equal to or above the cut-off score. Soccer training experience has no significant influence on the association between Lower Quarter Y-Balance Test anterior reach asymmetry and noncontact lower limb injury in young male players.

Utility of a Physical Fitness Score in Screening for Chronic Diseases.

We developed a new Physical Score (PS) consisting of comprehensive physical fitness indicators and elucidated the association between the resultant PS and metabolic diseases, i.e., diabetes, hypertension, dyslipidemia, fatty liver, and metabolic syndrome (MetS), among Japanese. Analyzed were 49,850 persons (30,039 men) aged 30 to 69 y who underwent physical fitness tests. Principal component analysis was performed on the correlation matrix of the physical fitness test results (relative grip strength, single-leg balance with eyes closed, and forward bending) according to sex and age. We defined the PS as the first principal component score. A formula was developed for various age groups comprised of men and women from 30 to 69 years of age from which the PS for each age and sex was calculated. The PS for both men and women was normally distributed with a value of 0 ± 1.15-1.16. Multivariate logistic regression analysis showed that the risk of metabolic diseases increased approximately 1.1-1.6 times per each 1-point reduction in the PS. The association between PS and MetS was particularly strong in that a 1-point reduction in the PS increased the risk of MetS by 1.54 times (95% confidence interval 1.46 to 1.62) in men and by 1.21 times (1.15 to 1.28) in women. The association between a lower PS and disease risk was stronger in younger men for fatty liver and in older men for MetS. Conversely, in women, the association between a lower PS and disease risk was stronger in older women for fatty liver and in younger women for MetS. For diabetes, hypertension, and dyslipidemia, the change in the impact of PS reductions across age groups was small. The PS is a useful and simple non-invasive tool for screening Japanese people for metabolic diseases.

The Effect of Fatigue on Postural Control and Biomechanical Characteristic of Lunge in Badminton Players.

This study investigated the effects of fatigue on postural control and biomechanical characteristic of lunge. A total of twelve healthy male collegiate badminton players (21.1 ± 2.2 years; 180.8 ± 4.0 cm; 72.5 ± 8.4 kg; 8.9 ± 3.5 years of experience) performed repeating lunges until exhausted. Postural stability was evaluated through a single-leg balance test using the dominant lower limb on a pressure plate with eyes opened (EO) and eyes closed (EC). The center of pressure (CoP) sway in the entire plantar and sub-regions of the plantar was measured. Kinematic and kinetic data of lunge motion were collected. The postural control was impaired after fatigue. In plantar sub-regions, the area, displacement and distance in the medial-lateral (ML) and anterior-posterior directions of CoP increased significantly (p < 0.05), especially the distance in ML. The medial region of the forefoot is the most sensitive to fatigue. Compared to pre-fatigue, participants experienced a significantly longer phase of pre-drive-off (p < 0.01), less peak moment and peak power of the knee and hip for drive-off (p < 0.01) and less peak moment of the ankle during braking phase (p < 0.05). These findings indicate that, within the setting of this investigation, the different responses to fatigue for CoP sway in plantar sub-regions and the consistency between postural control and biomechanical characteristic of lunge may be beneficial for developing and monitoring a training plan.