Predictor Of Physical Performance Research Articles

Wagner diagram for modeling O2 pathway—calculation and graphical display by the Helsinki O2 Pathway Tool

Objective. Maximal O2 uptake ( V˙O2max ) reflects the individual’s maximal rate of O2 transport and utilization through the integrated whole-body pathway composed of the lungs, heart, blood, circulation, and metabolically active tissues. As such, V˙O2max is strongly associated with physical capacity as well as overall health and thus acts as one predictor of physical performance and as a vital sign in determination of status and progress of numerous clinical conditions. Quantifying the contribution of single parts of the multistep O2 pathway to V˙O2max provides mechanistic insights into exercise (in)tolerance and into therapy-, training-, or disuse-induced adaptations at individual or group levels. We developed a desktop application (Helsinki O2 Pathway Tool—HO2PT) to model numerical and graphical display of the O2 pathway based on the ‘Wagner diagram’ originally formulated by Peter D. Wagner and his colleagues. Approach. The HO2PT was developed and programmed in Python to integrate the Fick principle and Fick’s law of diffusion into a computational system to import, calculate, graphically display, and export variables of the Wagner diagram. Main results. The HO2PT models O2 pathway both numerically and graphically according to the Wagner diagram and pertains to conditions under which the mitochondrial oxidative capacity of metabolically active tissues exceeds the capacity of the O2 transport system to deliver O2 to the mitochondria. The tool is based on the Python open source code and libraries and freely and publicly available online for Windows, macOS, and Linux operating systems. Significance. The HO2PT offers a novel functional and demonstrative platform for those interested in examining V˙O2max and its determinants by using the Wagner diagram. It will improve access to and usability of Wagner’s and his colleagues’ integrated physiological model and thereby benefit users across the wide spectrum of contexts such as scientific research, education, exercise testing, sports coaching, and clinical medicine.

Less daytime sleepiness and slow wave activity during sleep predict better physical readiness in military personnel

BackgroundMilitary personnel must maintain physical performance despite exposure to operational stressors such as sleep loss, caloric restriction and high cognitive load. Habitual sleep and specific sleep features are positively associated with fitness and may contribute to physical performance in operational settings. Further, by affecting muscle recovery, sleep may contribute to the ability to maintain performance across multiple days of exposure to operational stressors. ObjectivesWe examined the role of individual differences in baseline sleep on baseline physical performance and on change in physical performance throughout exposure to simulated military operational stress (SMOS). MethodsMilitary personnel (36 male, 9 female, 26.3 ± 5.3 years) completed a 5-day SMOS protocol during which they completed a tactical mobility test daily. Sleep questionnaires were administered at intake and sleep was monitored each night with polysomnography. Lasso regressions were used to identify meaningful predictors of physical performance at baseline and of change in physical performance across SMOS. ResultsBetter aerobic fitness, lower daytime sleepiness (Epworth Sleepiness Scale), and lower absolute slow wave activity (0.5-4 Hz) predicted better physical performance at baseline (66.1% of variance explained), but did not relate to changes in performance. ConclusionsCollectively, higher daytime sleepiness and slow wave activity may reflect more chronic exposure to insufficient sleep and higher baseline sleep drive, which in turn led to compromised physical performance. The findings suggest that low self-report sleepiness and low objective slow wave activity may reflect two quantifiable markers of healthy sleep behaviors that have implications for operational performance.

Calf circumference has a positive correlation with physical performance among community-dwelling middle-aged, older women.

Sarcopenia and frailty are well-known public health problems in middle-aged and older people. Calf circumference (CC) is a representative anthropometric index that may be useful for screening sarcopenia. Physical performance, assessed by hand grip strength and gait speed, measures sarcopenia and frailty. This community-based, cross-sectional study was conducted in Guishan District, Taoyuan City, between April and October 2017 to investigate the relationship between CC and physical performance among community-dwelling middle-aged, older people in Taiwan and to evaluate potential sex differences. CC tends to be an efficient predictor of physical performance in community health screenings and outpatient clinics for community health examinations, where there is limited time for surveys. A total of 1,308 volunteers aged 50-85 were recruited. Volunteers who declined to participate, those with recent cardiovascular disease, and those with an inability to complete an interview, physical performance examinations, and body composition measurements were excluded from the study. A total of 828 participants were enrolled in this study (237 men and 591 women). The statistical methods applied in this study were the Mann-Whitney U-test, independent two-sample t-test, Chi-square test, and multivariate logistic regression models. Significant differences were observed in age, waist circumference, appendicular skeletal mass index, calf circumference, hand grip strength, and income between men and women. No significant differences were observed between the men and women regarding body mass index, gait speed, exercise habits, or underlying disorders of diabetes mellitus, hypertension, or hyperlipidemia. Comparing across three different CC tertiles, we discovered significant differences in age, body mass index, waist circumference, appendicular skeletal muscle index, gait speed, and hand grip strength in both men and women. On multivariate logistic regression, after adjusting for age, appendicular skeletal mass index, body mass index, exercise habits, income levels, and CC were positively correlated with physical performance as measured by both gait speed (β = 0.15, p = 0.01) and hand grip strength (β = 0.25, p < 0.001) in women, compared to only hand grip strength (β = 0.41, p < 0.001) in men. Lower calf circumference is an independent risk factor for poor physical performance, especially among women.

Predictors of physical performance in national level male Kho Kho players: a cross-sectional analysis

Predictors of physical performance in national level male Kho Kho players: a cross-sectional analysis

Novel echocardiographic measures of myocardial work predicts physical performance during prolonged strenuous exercise

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The North Sea Race, Laerdal Foundation Background Cardiac function is a major determinant of physical performance. Cardiac function at rest can be assessed by novel echocardiographic parameters of myocardial work. Physical performance can be accurately measured using sensors recording the power output during exercise. There is limited data on the relationship between resting echocardiographic parameters and power measurements during strenuous endurance exercise. The aim of this work was to study the relationship between power output during exercise and echocardiographic parameters of cardiac structure and function at rest, including echocardiographic parameters of myocardial work. Method Resting echocardiographic parameters of 40 healthy, middle aged, recreational athletes, were compared with power output recordings during two episodes of endurance exercise of different duration and intensity. The first exercise was a cardiopulmonary exercise (CPX) test, which included both a lactate threshold- and a maximal oxygen uptake test. The second exercise was a 91-km mountain bike leisure sport cycling race. Power output was measured on the bikes using power meters. All study subjects were assessed by echocardiography prior to the CPX test. Coronary Computed Tomography Angiography was performed 1-2 weeks after the race to exclude obstructive coronary artery disease. Results Study participants were 51.1 ±9.7 years old (73 % men), median 10.0 (7.0-21.3) years of endurance training, and a median of 10.0 (5.0-20.0) endurance exercise competitions during the past five years. Both left ventricular mass and left atrial volume were in the upper reference range: 84.0 (77.0-96.0) gram/m2, 32.0 ±8.5 mL/m2, and the left ventricles were mildly dilated; 81.6 (69.1-96.5) mL/m2 (end-diastole). Median exercise duration: CPX: 43 (IQR 40-45) minutes, race: 236 (214-268) minutes. Mean heart rate; CPX: 145 ±11 bpm, race: 154 ± 10 bpm. Maximal oxygen uptake (Vo2 max): 41.6 ±9 ml/min/kg. Mean power output: CPX: 2.9 ±0.5 watt/kg, race: 2.1 ±0.5 watt/kg. There were strong bivariate correlations between left atrial and ventricular volumes and performance parameters (Table 1). Left ventricular global longitudinal strain (LV GLS) was correlated with Vo2 max. The myocardial work parameters global wasted work (GWW) and global work efficiency (GWE) were correlated with all performance parameters except Vo2 max. In multivariable linear regression models, except for VO2 max, GWW was the most consistent and strongest predictor of physical performance in all models (Table 2). Conclusion The novel echocardiographic parameter of global wasted work (GWW), assessed at rest, was the strongest and most consistent predictor of physical work measured by power meters during prolonged strenuous exercise.

The relative contributions of adiposity and activity levels to physical performance in children with excess weight.

This study examined predictors of physical performance, a key aspect of quality of life, in children with excess weight. Participants were 269 children aged 6-12 years with a body mass index above the 85th percentile. Children completed a standardized physical performance task capturing lower extremity strength, balance, and gait speed. Height, weight, and waist circumference were objectively measured, and daily moderate-vigorous physical activity (min/day) and sedentary time (% of day) were assessed with a 7-day accelerometer protocol. Physical performance task completion averaged 15.0 (SD=2.5) seconds. Children with higher body mass index z-scores and waist circumferences had significantly longer task completion times. The task took 1.8 additional seconds per 1.0 body mass index z-score (p <.001), and 1.2 additional seconds for every 20 cm higher waist circumference (p <.001). Daily moderate-vigorous physical activity and sedentary time were unrelated to physical performance, and did not moderate its associations with the adiposity measures. Among children with excess weight, physical performance declines with increasing levels of total and central adiposity. Daily activity levels do not moderate this association. Interventions that directly target weight reduction would likely yield the greatest improvement in physical performance in children with overweight or obesity.

Kinesiophobia, physical performance, and health-related quality of life in patients with coronary artery disease.

Kinesiophobia is an important risk factor for physical activity and exercise restrictions. It is important to assess kinesiophobia and identify high-risk patients to help prevent sedentary behaviour and increase exercise participation among cardiac patients. To evaluate kinesiophobia and its association with physical performance, health-related quality of life (HRQOL), patients' limitations and symptoms, and disease history in patients with coronary artery disease (CAD). Fifty-two patients diagnosed with CAD were enrolled in this study. Kinesiophobia was assessed with the Tampa Scale of Kinesiophobia for Heart. The 5× Sit-to-Stand Test (5-STST), the Timed Up and Go Test (TUGT), and the 6-Minute Walk Test (6-MWT) were used to assess physical performance. Patients' limitations and symptoms and HRQOL were evaluated with the Cardiovascular Limitations and Symptoms Profile. CAD duration and history of myocardial infarction (MI) were also recorded. 87.2% of the patients had high level of kinesiophobia, which was higher in patients with previous MI compared to patients without history of MI (p = 0.031). Kinesiophobia was positively correlated with 5-STST duration, TUGT duration, angina, shortness of breath, HRQOL, and CAD duration, and it was negatively correlated with 6-MWT distance (p < 0.05). According to regression analysis, only angina was a significant predictor for kinesiophobia (p = 0.014). Kinesiophobia was found to be a predictor of physical performance and HRQOL (p < 0.05). Levels of kinesiophobia are high in patients with CAD, especially in those with a history of MI. Angina is a predictor of kinesiophobia while kinesiophobia is a predictor of both physical performance and HRQOL in CAD patients.

Can physical activity levels and relationships with energy expenditure change the clinical aspects of sarcopenia and perceptions of falls among elderly women? Observational cross-sectional study.

Physical activity (PA) is an effective strategy for managing sarcopenia in the elderly, but few studies have addressed PA levels regarding age-related changes. To ascertain the effects of elderly women's PA levels on sarcopenia, physical performance, handgrip strength and perception of the risk of falling, and their relationship with energy expenditure. Observational cross-sectional study conducted in the southern region of the city of São Paulo, Brazil. Forty-seven elderly women were evaluated and divided into three groups: low PA (n = 13); moderate PA (n = 16); and high PA (n = 18). Their PA levels were investigated through the International Physical Activity Questionnaire (IPAQ); sarcopenia index, through dual-energy radiological absorptiometry; physical performance through the Timed Up & Go test; handgrip strength, using a digital dynamometer; and perception of the risk of falling, through the Fall Risk Awareness Questionnaire. High PA level indicated higher skeletal muscle mass index, physical performance and IPAQ score, compared with low and moderate PA levels. Multiple linear regression analysis showed that higher IPAQ energy expenditure at high and moderate PA levels was a good predictor of higher physical performance and increased perception of the risk of falling. Elderly women classified as having high PA level showed improvements in sarcopenia, handgrip strength, physical performance and perception of the risk of falling. The IPAQ energy expenditure of the elderly women with high and moderate PA levels was a good predictor of physical performance and improved perception of the risk of falling.

Skeletal muscle mitochondrial DNA copy number and mitochondrial DNA deletion mutation frequency as predictors of physical performance in older men and women.

Mitochondrial DNA (mtDNA) quality and quantity relate to two hallmarks of aging-genomic instability and mitochondrial dysfunction. Physical performance relies on mitochondrial integrity and declines with age, yet the interactions between mtDNA quantity, quality, and physical performance are unclear. Using a validated digital PCR assay specific for mtDNA deletions, we tested the hypothesis that skeletal muscle mtDNA deletion mutation frequency (i.e., a measure of mtDNA quality) or mtDNA copy number predicts physical performance in older adults. Total DNA was isolated from vastus lateralis muscle biopsies and used to quantitate mtDNA copy number and mtDNA deletion frequency by digital PCR. The biopsies were obtained from a cross-sectional cohort of 53 adults aged 50 to 86 years. Before the biopsy procedure, physical performance measurements were collected, including VO2max, modified physical performance test score, 6-min walk distance, gait speed, grip strength, and total lean and leg mass. Linear regression models were used to evaluate the relationships between age, sex, and the outcomes. We found that mtDNA deletion mutation frequency increased exponentially with advancing age. On average from ages 50 to 86, deletion frequency increased from 0.008 to 0.15%, an 18-fold increase. Females may have lower deletion frequencies than males at older ages. We also measured declines in VO2max and mtDNA copy number with age in both sexes. The mtDNA deletion frequency measured from single skeletal muscle biopsies predicted 13.3% of the variation in VO2max. Copy number explained 22.6% of the variation in mtDNA deletion frequency and 10.4% of the lean mass variation. We found predictive relationships between age, mtDNA deletion mutation frequency, mtDNA copy number, and physical performance. These data are consistent with a role for mitochondrial function and genome integrity in maintaining physical performance with age. Analyses of mtDNA quality and quantity in larger cohorts and longitudinal studies could extend our understanding of the importance of mitochondrial DNA in human aging and longevity.

Aerobic fitness, upper-body strength and agility predict performance on an occupational physical ability test among police officers while wearing personal protective equipment

Police institutions often use Occupational Physical Ability Tests (OPATs) as a measure of occupational performance. These tests are utilized to mimic the daily and essential tasks performed by the police officers, but few are performed with load carriage (LC). The purpose of this study was to examine the physical performance predictors of an OPAT performed without (NPPE) and with (WPPE) LC. Thirteen federal highway police officers (age: 36.8±3.7 years, body mass: 89±10.7 kg, height: 180±5.6 cm) volunteered to complete a battery of physical fitness tests (aerobic power and capacity, muscular endurance, lower limb power, upper limb strength, agility and anaerobic power) and anthropometrics. Occupational performance was measured by the total OPAT time consisting of 7 sequential police tasks. All subjects randomly completed the tests on both LC conditions. Agility (P<0.01), lower limb power and height (P<0.05) were significantly related to performance in the NPPE OPAT. In the WPPE condition, aerobic power (absolute and relative) (P<0.01), lower limb power and agility (P<0.05). The best predictors for OPAT performance were agility (R2=0.45, P<0.01) in the NPPE condition, as well as relative aerobic power, upper limb strength and agility in the WPPE condition (R2=0.81, P<0.01). Different conditions of LC have distinct occupational performance predictors. Thus, considering LC, physical exercise programs aimed at improving police occupational performance should aim at improving agility, upper limb strength and aerobic fitness.

The association between anthropometric measures and physical performance in black adults of the North West Province, South Africa.

This study investigated associations between anthropometric measures and physical performance in black South African adults. It was hypothesized that noninvasive, simple anthropometric measurements, such as calf circumference (CC) and body mass index (BMI), may be useful predictors of physical performance and strength. Black human immunodeficiency virus (HIV) negative men and women (aged 32-93 years) participating in the Prospective Urban and Rural Epidemiology (PURE) study were enrolled at baseline in 2005 = 1428). Men and women's anthropometry, socio-demographics and physical activity (PA) were assessed at baseline, 5- and 10-year follow-up. Physical performance (walk speed, chair stand and handgrip strength [HGS]) were assessed at 10-year follow-up. Linear regression models adjusted for potential confounders were used to evaluate the association between anthropometric measures and physical performance. The combined overweight and obesity prevalence among both men (P = .02) and women (P < .001) increased significantly over 10 years, with significant increases over time in BMI and CC in the women, whereas PA decreased significantly over time in both men and women (P < .0001). BMI and CC were positively associated with HGS in the men (P = .02, P < .0001) and women (P < .0001), while CC was positively associated with walk speed in men only (P = .006) in the cross-sectional analysis of 2015 measurements. BMI and CC in both men and women were positively associated with HGS, but CC was associated with walk speed in the men only. Our study suggests that CC may be a useful predictor of physical performance in black men and to a limited extent in black women.

The effects of toe grip training on physical performance and cognitive function of nursing home residents

BackgroundToe grip-related training requires individuals to actively exercise muscles that are not frequently used; therefore, it may improve not only toe grip strength but also cognitive function. The purpose of this study was to examine the effects of toe grip-related training on predictors of physical performance and cognitive function in nursing home residents.MethodsA total of 35 nursing home residents (35 left and 35 right feet; mean age, 82.1 ± 7.9 years) were included in this study. The participants were divided into two groups: a training group and a control group. The Mini-Mental State Examination (MMSE) was used to assess the cognitive function of the participants, and the Fall Risk Index (FRI) was used to evaluate the risk of falls. Toe grip-related physical function was also assessed. Baseline endpoints were evaluated and the effects of toe grip-related training were examined following a 12-week training intervention.ResultsThe training group showed significant improvements in MMSE score, FRI score, toe grip strength, and the toe skill (TS) test; however, the control group did not show these changes. The training group showed significant increases in Δ MMSE, Δ toe grip strength, and Δ TS (right foot) than the control group. Stepwise regression analysis revealed that Δ toe grip strength is an independent factor of Δ MMSE.ConclusionsToe grip training improves not only toe grip strength itself, but also cognitive function. Furthermore, change in toe grip strength was an independent factor of change in MMSE in those populations.Trial registrationUMIN, UMIN000027437. Registered on 26 May 2017.

Muscle thickness contribution to sit-to-stand ability in institutionalized older adults.

Ultrasound is a low-cost, safe and accessible tool to use on muscle mass assessment. The relations between muscle thickness and lower limb function have not been investigated in institutionalized elderly people. The purpose of the present study was to investigate the associations among sit-to-stand capacity, ultrasound-measured rectus femoris muscle thickness, hand grip strength and anthropometrics in a population of institutionalized older adults. Twelve older adults (nine women and three men, mean age ± SD 86 ± 7years, body mass index 24 ± 3kg/m2) participated in this cross-sectional study. Sit-to-stand capacity using five-repetition sit-to-stand test, rectus femoris muscle thickness using B-mode ultrasonography, handgrip and anthropometric were measured. The relationships of the variables were analyzed using Pearson correlation coefficient and multiple linear regression analysis. Significant bivariate correlations were found between rectus femoris muscle thickness and sit-to-stand test (p < 0.05). Multiple linear regression analysis showed associations between rectus femoris muscle thickness and sit-to-stand test, after adjusting by body mass index and age (p < 0.0001). Rectus femoris thickness in contraction adjusted by body mass index and age was predictors of physical performance. The independent variables shared 78.6% of variance in the sit-to-stand test. Rectus femoris muscle thickness measured with ultrasonography, body mass index and age could explain functionality in institutionalized older adults measured by five-repetition sit-to-stand test.

Physical Performance Predictors for Incident Dementia Among Japanese Community-Dwelling Older Adults.

Evaluating physical performance could facilitate dementia risk assessment. However, findings differ regarding which type of physical performance best predicts dementia. The objective of this study was to examine the association between physical performance and incidence of dementia in Japanese community-dwelling older adults. This was a prospective study of community-dwelling older adults. Of 14,313 invited individuals who were ≥65 years old, 5104 agreed to participate from 2011 to 2012, and 4086 (52% women; mean age=72.0 years) met the criteria. Baseline assessments of the following physical performance indicators were obtained: grip strength, the Five-Times Sit-to-Stand Test, and the Timed "Up & Go" Test. The physical performance level in each test was categorized as C1 (highest), C2 (middle-high), C3 (middle-low), or C4 (lowest) on the basis of sex-stratified quartile values. Incident dementia status was obtained from medical records that were updated monthly. During follow-up (mean duration=42.9 months), there were 243 incident cases of dementia (5.9%). Log-rank test results indicated that a lower physical performance level constituted a significant risk factor for dementia. After adjustment for covariates, Cox proportional hazards models (reference: highest physical performance level [C1]) demonstrated that the Five-Times Sit-to-Stand Test in the group with the lowest physical performance level (hazard ratio=1.69; 95% CI=1.10-2.59) was significantly associated with a risk of dementia. Likewise, the Timed "Up & Go" Test in the group with the lowest physical performance level (hazard ratio=1.54; 95% CI=1.01-2.35) was significantly associated with a risk of dementia. However, grip strength was not significantly associated with a risk of dementia. This study was limited by the use of medical record data. A lower mobility-related physical performance level was associated with dementia risk. Dementia risk assessment should include an adequate evaluation of physical function.

Possible Hormone Predictors of Physical Performance in Adolescent Team Sport Athletes.

Martin, AC, Heazlewood, IT, Kitic, CM, Lys, I, and Johnson, L. Possible hormone predictors of physical performance in adolescent team sport athletes. J Strength Cond Res 33(2): 417-425, 2019-The research aim of this study was to determine possible hormone predictors of physical performance in adolescent team sport athletes. Saliva samples were collected immediately before performance testing sessions from 114 state squad athletes (77 males, 37 females) participating in either Australian football, basketball, hockey, or netball. Participants completed tests of aerobic and anaerobic capacity, agility, power, and speed. Samples were collected over 22 months at quarterly, six-monthly, and/or yearly intervals depending on the testing schedule of the athlete. Saliva was analyzed for testosterone (T), cortisol (C), estradiol (E), and progesterone (P) levels. A strong negative correlation existed between multistage fitness test performance and T:E ratio (r = -0.76, p = 0.01) in females not taking oral contraceptives, and a strong positive correlation existed between repeat agility total time and estradiol levels (r = -0.71, p = 0.001) in females taking oral contraceptives. In males, strong negative correlations were evident for individual changes in planned agility time and estradiol levels (r = 0.87, p = 0.02), and countermovement jump (CMJ) height and T:C (r = -0.88, p = 0.01). In females taking oral contraceptives, a strong positive correlation was noted between individual change in yo-yo intermittent recovery test performance and T:E (r = 0.74, p = 0.01) and a strong negative correlation was noted between 20-m speed and T:P (r = 0.73, p = 0.01). In females not taking oral contraceptives, a strong negative correlation was found between individual change in CMJ height and T:P (r = -0.72, p = 0.02). The findings show that in adolescent team sport athletes, the P:E, T:E, and the T:P ratios are important predictors of performance in tests of physical capacity. The findings also indicate that estradiol and progesterone have a predictive function in the physical performance of adolescent male team sport athletes.

Body composition as a predictor of physical performance in older age: A ten-year follow-up of the Helsinki Birth Cohort Study

BackgroundThis study assessed how different measures of body composition predict physical performance ten years later among older adults. MethodsThe participants were 1076 men and women aged 57 to 70 years. Body mass index (BMI), waist circumference, and body composition (bioelectrical impedance analysis) were measured at baseline and physical performance (Senior Fitness Test) ten years later. Linear regression analyses were adjusted for age, education, smoking, duration of the follow-up and physical activity. ResultsGreater BMI, waist circumference, fat mass, and percent body fat were associated with poorer physical performance in both sexes (standardized regression coefficient [β] from −0.32 to −0.40, p < 0.001). Lean mass to BMI ratio was positively associated with later physical performance (β = 0.31 in men, β = 0.30 in women, p < 0.001). Fat-free mass index (lean mass/height2) in both sexes and lean mass in women were negatively associated with later physical performance. Lean mass residual after accounting for the effect of height and fat mass was not associated with physical performance. ConclusionsAmong older adults, higher measures of adiposity predicted poorer physical performance ten years later whereas lean mass was associated with physical performance in a counterintuitive manner. The results can be used when appraising usefulness of body composition indicators for definition of sarcopenic obesity.

The inter-individual relationship between training status and activity pattern during small-sided and full-sized games in professional male football players

ABSTRACTObjectives: We analysed the inter-individual relationship between training status and activity pattern in small-sided games (SSG) and full-sized games (FG).Methods: Fourteen Italian elite male senior football players were monitored during four training sessions incorporating SSG, and six FG, during the pre-season. Baseline measurements included, countermovement jump (CMJ), 5-m sprint time and Yo-Yo intermittent recovery test level 1 distance (YYIR1). Activity pattern was collected via 15-Hz global positioning system with 100-Hz accelerometer integrated.Results: Maximum accelerations (Accmax) and maximum decelerations (Decmax) showed moderate correlations (P < 0.05; r = 0.49 and 0.52) between SSG and FG. YYIR1 correlated with total distance covered (TD) in both SSG and FG (P < 0.05; r = 0.42 to 0.57) and with high-intensity distance (HIR) during FG (P < 0.05; r = 0.46 ± 0.38). CMJ showed positive correlations with TD, Accmax, Decmax, total accelerations (Acctot) and total decelerations (Dectot) during FG (P < 0.05; r = 0.40 ± 0.38, 0.41 ± 0.40, 0.46 ± 0.38, 0.65 ± 0.29, 0.57 ± 0.33). Multiple regression analysis revealed Decmax during SSG, as significant predictor of physical performance during FG, explaining a significant amount of variation in HIR, very-high speed running, Accmax and Decmax (P < 0.05; R2 = 0.49, 0.44, 0.26 and 0.49) during FG.Conclusions: SSG seems more effective to enhance muscular efforts occurring during FG, such as accelerations and decelerations, rather than speed patterns. Specifically, Decmax distance imposed during SSG was identified as the predictor of players’ movement patterns during FG. Thus, importance of eccentric strength (i.e. imposed when decelerating) to achieve football-specific fitness is emphasised. These findings may assist coaches and any football practitioners for pre-season programming.

The Utility of Objective Strength and Functional Performance to Predict Subjective Outcomes After Anterior Cruciate Ligament Reconstruction.

Background:Many clinicians release patients to return to activity after anterior cruciate ligament reconstruction (ACLR) based on time from surgery despite deficits in muscle strength and function. It is unclear whether symmetry or unilateral performance is the best predictor of subjective outcomes after ACLR.Purpose:To determine physical performance predictors of patient-reported outcomes after reconstruction.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 88 participants (49 males, 39 females; mean ± SD height, 174.0 ± 9.6 cm; weight, 76.1 ± 18.5 kg; age, 19.4 ± 3.7 years) who underwent primary, unilateral ACLR volunteered for this study. Participants had undergone reconstruction a mean of 6.9 ± 1.8 months (range, 5.0-14.1 months) before the study. All participants underwent strength testing as well as hop testing and then completed the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires. Stepwise linear regression models were used for symmetry and unilateral performance to identify the proportion of variance explained in the IKDC score, KOOS total score, KOOS-sport subscale, and time from surgery, as well as receiver operating characteristic (ROC) curve analyses on those variables that explained the most variance in patient-reported outcomes to determine cutoff thresholds.Results:No significant correlations were found between time from surgery and objective performance. The only significant predictors of IKDC score were single-hop limb symmetry index (LSI) and age (R 2 = 0.177) and unilateral triple-hop performance and age (R 2 = 0.228). The cutoff for single-hop symmetry was 0.92 (area under the curve [AUC], 0.703; P = .012), and the cutoff for normalized triple-hop distance was 3.93 (AUC, 0.726; P = .005). When stratified by age, the cutoff for single-hop symmetry was 0.81 (AUC, 0.721; P = .051) for younger patients (age <19.1 years) and was not significant for older patients (age ≥19.1 years). The cutoff for normalized triple-hop distance was 3.85 (AUC, 0.832; P = .005) in older patients and was not significant for younger patients. The only significant predictors of KOOS-sport subscale were single-hop LSI (R 2 = 0.140) and normalized knee extensor power at 180 deg/s (R 2 = 0.096). When subjective outcomes were predicted based on KOOS-sport subscale, the cutoff for single-hop symmetry was 0.85 (AUC, 0.692; P = .018).Conclusion:Hopping performance is the most predictive functional variable of subjective outcomes after reconstruction. Single-hop symmetry was most important for younger patients and unilateral triple-hop distance was most important for older patients. Clinicians should consider hopping performance when making return-to-activity decisions after ACLR.

Association between Toe Grip Strength and Physical Performance Among Japanese Preschool Children

Objective: To evaluate the association between Toe grip strength (TGS) and physical performance among preschool children in Japan. Methods: TGS was evaluated in 338 preschool children (178 boys, 160 girls), 4–6 years of age. The following physical performance tests were measured: hand grip strength (HGS), 25-m sprint run, 5-m shuttle run, standing long jump, and tennis ball throw, were measured. Participants were divided into five age groups of 6-month intervals, from the early 4-years-old group (48-53 months) to the early 6-years-old group (72-78 months). TGS was analyzed using a two-way analysis of variance, with a post-hoc test to assess between-sex differences and age-related changes. Associations between TGS and descriptive characteristics and physical performance were assessed using multivariate linear regression analysis. Results: TGS increased with development, being significantly greater in the early 6-years-old group than in the early and late 4-years-old group and early 5-years-old group. There was no between-sex difference in TGS within the same age group. TGS was associated with age in months and weight, but not with sex and height. TGS was also significantly associated with the 25-m sprint run, 5-m shuttle run and standing long jump performance, regardless of age, anthropometrics and HGS, in both sex, with the exception of the 5-m shuttle run in boys. Conclusion: TGS increased with age and was associated with enhanced lower-limb physical performance among preschool children and could provide a useful predictor of physical performance in this population.

Preoperative physical performance predictors of self-reported physical function and quality of life in patients scheduled for total knee arthroplasty.

[Purpose] To determine the preoperative self-reported and performance-based physical function of patients with end-stage knee osteoarthritis who awaited total knee arthroplasty. The preoperative physical performance factors that predicted self-reported physical function and quality of life were also identified. [Subjects and Methods] All adults with end-stage knee osteoarthritis awaiting surgery were enrolled. Before surgery, self-reported disease-specific physical function and self-reported pain were measured using the Western Ontario McMaster Universities Osteoarthritis Index, self-reported quality of life was measured using the EuroQOL five dimensions questionnaire, and physical performance tests were performed, the 6 minute walk test, the timed up-and-go test, instrumental gait analysis, and measurement of isometric knee flexor and extensor strength of the surgical and nonsurgical knees. [Results] In total, 55 adults (49 females; 73.3 ± 6.1 years) were included. This study showed that several preoperative self-reported and physical performance factors were predictive of self-reported physical function and quality of life. [Conclusion] In patients with end-stage knee osteoarthritis, preoperative pain and dynamic balance ability were the most powerful predictors of self-reported physical function. Preoperative pain and exercise tolerance were the most powerful predictors of quality of life. Preoperative rehabilitation strategies that focus on dynamic balance, aerobic, and resistance exercises may improve surgical outcomes.