Position-specific performance indicators that discriminate between successful and unsuccessful teams in elite women's indoor field hockey: implications for coaching.

The aim of this investigation was to establish median performance profiles for the six playing positions in elite women's indoor hockey and then identify whether these position-specific profiles could discriminate between qualifying (top four), mid-table and relegated teams in the 2011-2012 England Hockey premier league. Successful passing in relegated teams was significantly lower (P < 0.008) than in mid-table and qualifying teams in four of the five outfield positions. Furthermore, the right backs of qualifying teams demonstrated significantly fewer (P < 0.008) unsuccessful passes (x̃ = 15.5 ± CLs 15.0 and 10.0, respectively) and interceptions (x̃ = 4.0 ± CLs 4.0 and 3.0, respectively) than relegated teams (x̃ = 19.5 ± CLs 21.0 and 17.0; x̃ = 7.5 ± CLs 8.0 and 6.0, respectively). Finally, the right forwards of relegated teams demonstrated significantly fewer (P < 0.008) successful interceptions (x̃ = 4.0 ± CLs 5.0 and 4.0, respectively) than qualifying teams (x̃ = 5.0 ± CLs 6.0 and 3.0, respectively) and significantly more (P < 0.008) unsuccessful interceptions (x̃ = 5.5 ± CLs 6.0 and 4.0, respectively) than mid-table teams (x̃ = 3.0 ± CLs 3.0 and 2.0, respectively). Based on these findings, coaches should adapt tactical strategies and personnel deployment accordingly to enhance the likelihood of preparing a qualifying team. Research should build from these data to examine dribbling, pressing and patterns of play when outletting.

Validity and Test-Retest Reliability of the TIVRE-Basket Test for the Determination of Aerobic Power in Elite Male Basketball Players.

The aims of this study were to (a) determine the relationship between performance on the court-based TIVRE-Basket test and peak aerobic power determined from a criterion laboratory-based incremental treadmill test and (b) to examine the test-retest reliability of the TIVRE-Basket test in elite male basketball players. To address aim 1, 36 elite male basketball players (age: 25.2 ± 4.7 years, weight: 94.1 ± 11.4 kg, height: 195.83 ± 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket within 72 hours. The mean distance recorded during the TIVRE-Basket test was 4001.8 ± 176.4 m, and mean VO2 peak was 54.7 ± 2.8 ml · kg(-1) · min(-1), and the correlation between the 2 parameters was r = 0.824 (p ≤ 0.001). Linear regression analysis identified TIVRE-Basket distance (in meters) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + (0.13 × TIVRE-Basket distance [in meters]). Performance on the TIVRE-Basket test accounted for 67.8% of the variance in VO2 peak (t = 8.466, p ≤ 0.001, 95% confidence interval: 0.01-0.016, SEE: 1.61). To address aim 2, 20 male basketball players (age: 26.7 ± 4.2 years, height: 1.94 ± 0.92 cm, weight: 94.0 ± 9.1 kg) performed the TIVRE-Basket test on 2 occasions. There was no significant difference in total distance covered between trial 1 (4138.8 ± 677.3 m) and trial 2 (4188.0 ± 648.8 m; t = 0.5798, p = 0.5688). Mean difference between trials was 49.2 ± 399.5 m, with an intraclass correlation coefficient of 0.85 suggesting a moderate level of reliability. Standardized typical error of measurement was 0.88%, representing a moderate degree of trial-to-trial error, and the Coefficient of Variation (CV) was 6.3%. The TIVRE-Basket test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite-level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations, for example, across age groups, at different levels of competition, in females and in different forms of the game, for example, wheelchair basketball.

The Effects of Static Stretching Intensity on Range of Motion and Strength: A Systematic Review.

The aim of this study was to systematically review the evidence on the outcomes of using different intensities of static stretching on range of motion (ROM) and strength. PubMed, Web of Science and Cochrane controlled trials databases were searched between October 2021 and February 2022 for studies that examined the effects of different static stretching intensities on range of motion and strength. Out of 6285 identified records, 18 studies were included in the review. Sixteen studies examined outcomes on ROM and four on strength (two studies included outcomes on both ROM and strength). All studies demonstrated that static stretching increased ROM; however, eight studies demonstrated that higher static stretching intensities led to larger increases in ROM. Two of the four studies demonstrated that strength decreased more following higher intensity stretching versus lower intensity stretching. It appears that higher intensity static stretching above the point of discomfort and pain may lead to greater increases in ROM, but further research is needed to confirm this. It is unclear if high-intensity static stretching leads to a larger acute decrease in strength than lower intensity static stretching.

Discrepancies in accelerometer-measured physical activity in children due to cut-point non-equivalence and placement site.

This study examined dissonance in physical activity (PA) between two youth-specific hip-derived intensity cut-points for the Actiwatch (AW), and compared PA between hip and wrist placements using site-specific cut-points. Twenty-four children aged 11.2 ± 0.5 years wore the AW on the right hip and non-dominant wrist during a typical school day. Minutes of sedentary behaviour and vigorous activity were greater using Puyau et al. (2002) cut-points, but light, moderate, and moderate-to-vigorous (MVPA) were greater when derived using Puyau et al. (2004) cut-points (P < 0.01). Total hip activity counts were lower than wrist. Sedentary minutes were greater at the hip, but minutes of light, vigorous and MVPA were lower (P < 0.01). Moderate minutes were greater at the hip, but differed only when applying the Puyau et al. (2004) cut-points (P < 0.01). In conclusion, data comparisons between two hip derived AW cut-points and between hip and wrist data are inappropriate. Future researchers using the AW at the hip should present data reduced using both published cut-points. As hip and wrist data differ, the wrist placement is preferable as it will likely increase children's compliance to monitoring protocols due to reduced obtrusiveness compared to the hip.

Acute appetite and eating behaviour responses to apparatus-free, high-intensity intermittent exercise in inactive women with excess weight.

High-intensity intermittent exercise (HIIE) has been shown to transiently suppress appetite, but such exercise has traditionally required the use of specialist apparatus (e.g., cycle ergometer). This study aimed to determine appetite and eating behaviour responses to acute apparatus-free HIIE in inactive women with excess weight. A preliminary study (n = 18 inactive women, 9 healthy weight, 18.0-24.9 kg∙m-2; 9 with excess weight, 25.0-34.9 kg∙m-2) revealed that intervals of 30 s of "all out" star jumping elicited physiological responses akin to intervals of 30 s of "all out" cycling. Twelve women (29.2 ± 2.9kg∙m-2, 38 ± 7years, 28 ± 39 min MVPA∙week-1) then completed three trials in a within-subject, randomised cross-over design: 4 × 30 s "all out" star jumping (4 × 30 s); 2 × 30 s "all out" star jumping (2 × 30 s); resting control (CONT). Upon completing each late-morning exercise trial, lunch was provided upon request from the participant. The time from the exercise bout to lunch request - termed eating latency - was recorded, and ad libitum food intake at lunch was measured. Subjective appetite was measured using a visual analogue scale before and after exercise, and at lunch request. Free-living energy intake (EI) and energy expenditure (EE) were recorded for the remainder of the trial day and the three days following. Change-from-baseline in subjective appetite was significantly lower immediately after 4 × 30 s (-9.6 ± 18.4 mm) and 2 × 30 s (-11.5 ± 21.2 mm) vs. CONT (+8.1 ± 9.6 mm), (both p < 0.05, d = 0.905 and 1.027, respectively). Eating latency (4 × 30 s: 32 ± 33 min, 2 × 30 s: 31 ± 26 min, CONT: 27 ± 23 min, p = 0.843; η2p = 0.017) and lunch EI (4 × 30 s: 662±178 kcal, 2 × 30 sec: 715 ± 237 kcal, CONT: 726 ± 268 kcal, p = 0.451; η2p = 0.077) did not differ significantly between conditions. No significant differences were observed in trial day EI and EE, or in EI and EE on the three days following exercise (all p > 0.05). Mean trial day relative EI (EI - EE) was 201 ± 370 kcal lower after 4 × 30 s than CONT, but this difference was not statistically significant (p = 0.303, d = 0.585). In conclusion, very low-volume star jumping elicited a transient suppression of appetite without altering eating behaviour. (313 words).

Predicting field-goal success according to offensive, defensive and contextual variables in elite men's wheelchair basketball.

The purposes of this study were to (i) develop a field-goal shooting performance analysis template and (ii) explore the impact of each identified variable upon the likely outcome of a field-goal attempt using binary logistic regression modelling in elite men's wheelchair basketball. First, a field-goal shooting performance analysis template was developed that included 71 Action Variables (AV) grouped within 22 Categorical Predictor Variables (CPV) representing offensive, defensive and game context variables. Second, footage of all 5,105 field-goal attempts from 12 teams during the men's 2016 Rio De Janeiro Paralympic Games wheelchair basketball competition were analysed using the template. Pearson's chi-square analyses found that 18 of the CPV were significantly associated with field-goal attempt outcome (p < 0.05), with seven of them reaching moderate association (Cramer's V: 0.1-0.3). Third, using 70% of the dataset (3,574 field-goal attempts), binary logistic regression analyses identified that five offensive variables (classification category of the player, the action leading up to the field-goal attempt, the time left on the clock, the location of the shot, and the movement of the player), two defensive variables (the pressure being exerted by the defence, and the number of defenders within a 1-meter radius) and 1 context variable (the finishing position of the team in the competition) affected the probability of a successful field-goal attempt. The quality of the developed model was determined acceptable (greater than 65%), producing an area under the curve value of 68.5% when the model was run against the remaining 30% of the dataset (1,531 field-goal attempts). The development of the model from such a large sample of objective data is unique. As such it offers robust empirical evidence to enable coaches, performance analysts and players to move beyond anecdote, in order to appreciate the potential effect of various and varying offensive, defensive and contextual variables on field-goal success.

Development and Initial Validation of the Humor Climate in Sport Scale.

In sport teams, humor is an essential element that influences communication processes, and plays an important role in group dynamics. Despite this, no current instrument is presented in the literature to measure humor climate in sport teams. Therefore, the current study presents the development and initial validation of the Humor Climate in Sport Scale (HCSS). The aim was to assess content, structural and concurrent validity of the developed instrument, and to examine differential item functioning (DIF) as a function of sex. Three different phases were completed in this study. The first phase involved focus groups (n = 5) that explored humor as communication in a team sport context. In phase 2, information from the focus groups was used to create a pool of potential items for the questionnaire. Two discussion groups with sport science students contributed to the development of 80 potential items, that two different expert groups then assessed for item quality. The final version of the instrument after this phase contained 14 items, representing three different humor dimensions. In phase 3, two independent samples with a total number of 776 participants were recruited for the psychometric evaluation of the instrument. EFA, ICM-CFA, and ESEM analysis were performed, supporting a three-factor structure with positive humor, negative humor in-group, and negative humor out-group. In addition, partial DIF as a function of sex on the negative humor dimensions was found, indicating differences in how male and female interpret the negative humor items. The findings in the current study expand our understanding of humor in sport teams and may be a starting point for further research on humor climate in sport teams and its role in group function.

Seasonal variation in physiological fitness of a semiprofessional soccer team.

The purpose of this study was to investigate seasonal variations in physiological fitness of semiprofessional soccer players over a 12-month period. Thirteen male players were tested 5 times over a 12-month period using bioelectrical impedance, a 20-m multistage fitness test, countermovement standing vertical jump, 15-m sprint test, Illinois agility test, and sit and reach test. Significant deconditioning was apparent in all fitness variables from end of season one season to prepreseason training of the next season. Aerobic fitness, vertical jump, percent body fat, agility, and sprint performance improved from prepreseason to midseason. Significant decreases in aerobic fitness and the cessation of significant increases in vertical jump, sprint, and agility performance were shown from midseason onward. No differences between the fitness components at the end of season one and the end of season two were identified. The deconditioning apparent in all fitness parameters during the off season, together with progressive improvement in most from postpreseason to midseason would support these parameters as sport-specific fitness requirements. Such improvements suggest that the short-term demands of playing and training in the first half of the season develop fitness and these trends are similar to those for professional players. Body fat was also shown to be detrimental to sprint performance throughout the 12-month period. Further research is needed to identify if the plateau in fitness from midseason is the result of attaining the required level of fitness, fatigue, allied training, or even relative success. Enhancing off-season training may enable yearly fitness increases by at least maintaining fitness levels for the next year's preseason.

Making Every "Point" Count: Identifying the Key Determinants of Team Success in Elite Men's Wheelchair Basketball.

Wheelchair basketball coaches and researchers have typically relied on box score data and the Comprehensive Basketball Grading System to inform practice, however, these data do not acknowledge how the dynamic perspectives of teams change, vary and adapt during possessions in relation to the outcome of a game. Therefore, this study aimed to identify the key dynamic variables associated with team success in elite men's wheelchair basketball and explore the impact of each key dynamic variable upon the outcome of performance through the use of binary logistic regression modeling. The valid and reliable template developed Francis et al. (2019) was used to analyze video footage in SportsCode from 31 games at the men's 2015 European Wheelchair Basketball Championships. The 31 games resulted in 6,126 rows of data which were exported and converted into a CSV file, analyzed using R (R Core Team, 2015) and subjected to a data modeling process. Chi-square analyses identified significant (p < 0.05) relationships between Game Outcome and 19 Categorical Predictor Variables. Automated stepwise binary regression model building was completed using 70% of the data (4,282 possessions) and produced a model that included 12 Categorical Predictor Variables. The accuracy of the developed model was deemed to be acceptable at accurately predicting the remaining 30% of the data (1,844 possessions) and produced an area under the receiver operating characteristic curve value of 0.759. The model identified the odds of winning are more than double when the team in possession are in a state of winning at the start of the possession are increased five-fold when the offensive team do not use a 1.0 or 1.5 classified player, but are increased six-fold when the offensive team use three or more 3.0 or 3.5 players. The final model can be used by coaches, players and support staff to devise training and game strategies that involve selecting the most appropriate offensive and defensive approaches when performing ball possessions to enhance the likelihood of winning in elite men's wheelchair basketball.

A New Reliable Performance Analysis Template for Quantifying Action Variables in Elite Men's Wheelchair Basketball.

This study aimed to develop a valid and reliable performance analysis template for quantifying team action variables in elite men's wheelchair basketball. First action variables and operational definitions were identified by the authors and verified by an expert panel of wheelchair basketball coaching staff in order to establish expert validity. A total of 109 action variable were then placed into 17 agreed Categorical Predictor Variable categories. The action variables were then used to develop a computerized performance analysis template for post-event analysis. Each possession (n = 200) from an international men's wheelchair basketball game was analyzed by the first author on two occasions for assessment of intra-observer reliability and by a coach and a performance analyst for inter-observer reliability. Percentage error and Weighted Kappa coefficients were calculated to compare the levels of error and agreement for each action variable. Intra-observer reliability demonstrated perfect or almost perfect agreement (

Preliminary evidence of reductive stress in human cytotoxic T cells following exercise.

This study investigated immunophenotypic differences in intracellular thiol redox state of peripheral blood mononuclear cells (PBMCs) isolated from trained [ n = 9, means ± SD: age 28 ± 5 yr; (body mass index) BMI 23.2 ± 2.6 kg/m2; V̇o2max (maximal oxygen intake)56.9 ± 6.1 ml·kg-1·min-1] and recreationally active (RA, n = 11, means ± SD: age 27 ± 6 yr; BMI 24.2 ± 3.7 kg/m2; V̇o2max 45.1 ± 6.4 ml·kg-1·min-1) participants before and after a maximal aerobic exercise tolerance test. Blood samples were taken before (Pre), during (sample acquired at 70% maximum heart rate), immediately after (Post + 0), and 15 min postexercise (Post + 15). PBMCs were isolated, and reduced thiol analysis [fluorescein-5 maleimide (F5M)] by immunophenotype [cluster of differentiation (CD)3+, CD4+, and CD8+] was performed using flow cytometry. A significant increase in cellular F5M fluorescence was observed in CD3+ T cells at Post + 0, with changes driven to a greater extent by CD8+ T cells (fold change in both groups CD4: +2.3, CD8: +2.8; P < 0.05). Further analysis revealed a population of highly reduced CD8+ T cells (CD8+T-reduced+) that significantly increased from Pre to Post + 0 in RA participants only (RA: +272 cell/µl, P < 0.05). To understand these results further, CD8+T-reduced+ and CD8+T-reduced- cells were analyzed for immunophenotype in response to the same exercise protocol ( n = 6, means ± SD: age 24 ± 5 yr; BMI 25.7 ± 4.1 kg·m-2; V̇o2max 41.33 ± 7.63 ml·kg-1·min-1). CD8+T-reduced+ had significantly less lymphoid homing potential (chemokine receptor type 7) Post + 0 compared with Pre. This study is the first, to our knowledge, to demonstrate that lymphocyte populations become more reductive in response to acute exercise. NEW & NOTEWORTHY The study presented provides the first evidence to suggest that cytotoxic T cells become transiently reductive in healthy individuals following a single bout of cycling. Detection of these cells was enabled via the use of a flow cytometric assay that incorporates the thiol reactive probe fluorescein-5 maleimide. Using this method, transient reductive stress in viable T cells is permissible and provides the basis for further research in the area of exercise immunology.

A Computer Model of Drafting Effects on Collective Behavior in Elite 10,000-m Runners.

PURPOSE: Drafting in cycling influences collective behavior of pelotons. Although evidence for collective behavior in competitive running events exists, it is not clear if this results from energetic savings conferred by drafting. This study modeled the effects of drafting on behavior in elite 10,000-m runners. METHODS: Using performance data from a men's elite 10,000-m track running event, computer simulations were constructed using Netlogo 5.1 to test the effects of 3 different drafting quantities on collective behavior: no drafting, drafting to 3 m behind with up to ~8% energy savings (a realistic running draft), and drafting up to 3 m behind with up to 38% energy savings (a realistic cycling draft). Three measures of collective behavior were analyzed in each condition: mean speed, mean group stretch (distance between first- and last-placed runner), and runner-convergence ratio (RCR), which represents the degree of drafting benefit obtained by the follower in a pair of coupled runners. RESULTS: Mean speeds were 6.32 ± 0.28, 5.57 ± 0.18, and 5.51 ± 0.13 m/s in the cycling-draft, runner-draft, and no-draft conditions, respectively (all P < .001). RCR was lower in the cycling-draft condition but did not differ between the other 2. Mean stretch did not differ between conditions. CONCLUSIONS: Collective behaviors observed in running events cannot be fully explained through energetic savings conferred by realistic drafting benefits. They may therefore result from other, possibly psychological, processes. The benefits or otherwise of engaging in such behavior are as yet unclear.

Participation motivation in martial artists in the west midlands region of England.

The objectives were to identify the participation motivations and the perceived importance of certain participation factors in martial artists in the West Midlands, England, UK. A 28-item adapted version of the Participation Motivation Questionnaire with additional demographic questions was distributed to 30 martial arts clubs in the West Midlands region. Eight questions that assessed the perceived importance for participation of progression through grades, learning self defence skills, technical ability of instructors, cost of participating, development of confidence, underpinning philosophy and instructional style were included. Seventy-five questionnaires were returned from a total of 11 clubs from across representing practitioners in Tai Chi, Karate, Kung fu, Aikido, Jeet Kune Do, British Free Fighting, Taekwon-Do and Jujitsu. Results indicated that the rank order in terms of participation motives was: 1-Affiliation; 2-Friendship; 3-Fitness; 4-Reward/status; 5-Competition; 6-Situational and 7-Skill development. Participants who trained for more than 4 hours per week placed greater importance on the underpinning philosophy of the martial art. Findings suggest that whilst there is a gender discrepancy in participation level, once engaged, females were equally committed to weekly training. The 'style' of the instructor is of paramount importance for enhancing student motivation to participate. High volume practitioners would appear to be fully immersed in the holistic appreciation of the martial art through increased value placed on its underpinning philosophy. Key PointsWhilst there is a gender discrepancy in participation level, once engaged, females were equally committed to weekly training.The four most important participation motivations evident were 'Affiliation', 'Fitness', 'Skill Development' and 'Friendship'.The three least influential motives were 'Rewards/status; 'Situational' and 'Competition'. " There were no significant gender or experience differences for any of the emergent motivational factors.Instructor 'style' is of paramount importance for enhancing student motivation to participate.

Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance.

PURPOSE: The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance. METHOD: Twenty-seven men (Mage = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual performance identified, and once in a group with individual performance not identified. Using a median split of the mental toughness index, participants were divided into high and low mental toughness groups. Cycling distance was compared using a 2 (trial) × 2 (high-low mental toughness) analysis of variance. We hypothesized that mentally tough participants would perform equally well under both conditions (i.e., no indication of social loafing) compared with low mentally tough participants, who would perform less well when their individual performance was not identifiable (i.e., demonstrating the anticipated social loafing effect). RESULTS: The high mental toughness group demonstrated consistent performance across both conditions, while the low mental toughness group reduced their effort in the non-individually identifiable team condition. CONCLUSIONS: The results confirm that (a) clearly identifying individual effort/performance is an important situational variable that may impact team performance and (b) higher perceived mental toughness has the ability to negate the tendency to loaf.

The Influence of Collective Behavior on Pacing in Endurance Competitions.

A number of theoretical models have been proposed in recent years to explain pacing strategies observed in individual competitive endurance events. These have typically related to the internal regulatory processes that inform the making of decisions relating to muscular work rate. Despite a substantial body of research which has investigated the influence of collective group dynamics on individual behaviors in various animal species, this issue has not been comprehensively studied in individual athletic events. This is somewhat surprising given that athletes often directly compete in close proximity to one another, and that collective behavior has also been observed in other human environments including pedestrian interactions and financial market trading. Whilst the reasons for adopting collective behavior are not fully understood, collective behavior is thought to result from individual agents following simple local rules that result in seemingly complex large systems that act to confer some biological advantage to the collective as a whole. Although such collective behaviors may generally be beneficial, competitive endurance events are complicated by the fact that increasing levels of physiological disruption as activity progresses may compromise the ability of some individuals to continue to interact with other group members. This could result in early fatigue and relative underperformance due to suboptimal utilization of physiological resources by some athletes. Alternatively, engagement with a collective behavior may benefit all due to a reduction in the complexity of decisions to be made and a subsequent reduction in cognitive loading and mental fatigue. This paper seeks evidence for collective behavior in previously published analyses of pacing behavior and proposes mechanisms through which it could potentially be either beneficial, or detrimental to individual performance. It concludes with suggestions for future research to enhance understanding of this phenomenon.

Older adults who have previously fallen due to a trip walk differently than those who have fallen due to a slip.

Studying the relationships between centre of mass (COM) and centre of pressure (COP) during walking has been shown to be useful in determining movement stability. The aim of the current study was to compare COM-COP separation measures during walking between groups of older adults with no history of falling, and a history of falling due to tripping or slipping. Any differences between individuals who have fallen due to a slip and those who have fallen due to a trip in measures of dynamic balance could potentially indicate differences in the mechanisms responsible for falls. Forty older adults were allocated into groups based on their self-reported fall history during walking. The non-faller group had not experienced a fall in at least the previous year. Participants who had experienced a fall were split into two groups based on whether a trip or slip resulted in the fall(s). A Vicon system was used to collect full body kinematic trajectories. Two force platforms were used to measure ground reaction forces. The COM was significantly further ahead of the COP at heel strike for the trip (14.3 ± 2.7 cm) and slip (15.3 ± 1.1 cm) groups compared to the non-fallers (12.0 ± 2.7 cm). COM was significantly further behind the COP at foot flat for the slip group (-14.9 ± 3.6 cm) compared to the non-fallers (-10.3 ± 3.9 cm). At mid-swing, the COM of the trip group was ahead of the COP (0.9 ± 1.6 cm), whereas for the slip group the COM was behind the COP (-1.2 ± 2.2 cm). These results show identifiable differences in dynamic balance control of walking between older adults with a history of tripping or slipping and non-fallers.

Age and grip strength predict hand dexterity in adults.

In the scientific literature, there is much evidence of a relationship between age and dexterity, where increased age is related to slower, less nimble and less smooth, less coordinated and less controlled performances. While some suggest that the relationship is a direct consequence of reduced muscle strength associated to increased age, there is a lack of research that has systematically investigated the relationships between age, strength and hand dexterity. Therefore, the aim of this study was to examine the associations between age, grip strength and dexterity. 107 adults (range 18-93 years) completed a series of hand dexterity tasks (i.e. steadiness, line tracking, aiming, and tapping) and a test of maximal grip strength. We performed three phases of analyses. Firstly, we evaluated the simple relationships between pairs of variables; replicating the existing literature; and found significant relationships of increased age and reduced strength; increased age and reduced dexterity, and; reduced strength and reduced dexterity. Secondly, we used standard Multiple Regression (MR) models to determine which of the age and strength factors accounted for the greater variance in dexterity. The results showed that both age and strength made significant contributions to the data variance, but that age explained more of the variance in steadiness and line tracking dexterity, whereas strength explained more of the variance in aiming and tapping dexterity. In a third phase of analysis, we used MR analyses to show an interaction between age and strength on steadiness hand dexterity. Simple Slopes post-hoc analyses showed that the interaction was explained by the middle to older aged adults showing a relationship between reduced strength and reduced hand steadiness, whereas younger aged adults showed no relationship between strength and steadiness hand dexterity. The results are discussed in terms of how age and grip strength predict different types of hand dexterity in adults.

Intra- and inter-instrument reliability of the actiwatch 4 accelerometer in a mechanical laboratory setting.

This study aimed to quantify the intra-and inter-instrument reliability of the Actiwatch 4 accelerometer (AW4) in a mechanical setting. Twenty seven AW4 were attached to an isokinetic dynamometer and subjected to angular acceleration for 30 min at 50 deg/sec representing moderate intensity (MPA condition) and 200 deg/sec representing vigorous intensity (VPA condition), with a repeat trial conducted. Reliability was assessed using coefficient of variation (CV), absolute percent error (APE), and intraclass correlation coefficients (ICC). Mean AW4 activity counts displayed acceptable reliability according to CV in both conditions (ConMPA: CVintra = 4.6%, APEintra = 6.6%, CVinter = 6.4%, APEinter = 5.2%; ConVPA: CVintra = 3.9%, APEintra = 5.6%, CVinter = 5.9%, APEinter = 4.7%). When counts were re-categorised into minutes of MPA and VPA, lower CV values were observed (ConMPA: CVintra = 3.2%, APEintra = 4.5%, CVinter = 4.3%, APEinter = 3.2%; ConVPA: CVintra = 0.0%, APEintra = 0.0%, CVinter = 0.0%, APEinter = 0.0%). When activity counts were re-categorised as minutes of MVPA, excellent reliability was observed (CVintra, APEintra, CVinter, and APEinter = 0.0%) in both conditions. Mean AW4 activity counts exhibit reliability statistics comparable to other accelerometers. Reliability is improved when activity counts are re-categorised as time spent in MPA and VPA, with greatest reliability obtained when counts are recategorised as time spent in MVPA. As MVPA is the subcomponent of physical activity most associated with health benefits it would appear that the AW4 is reliable for measuring time spent in this health enhancing intensity category, at least from testing in a mechanical laboratory setting.

Differences in axial segment reorientation during standing turns predict multiple falls in older adults.

BACKGROUND: The assessment of standing turning performance is proposed to predict fall risk in older adults. This study investigated differences in segmental coordination during a 360° standing turn task between older community-dwelling fallers and non-fallers. METHODS: Thirty-five older adults age mean (SD) of 71 (5.4) years performed 360° standing turns. Head, trunk and pelvis position relative to the laboratory and each other were recorded using a Vicon motion analysis system. Fall incidence was monitored by monthly questionnaire over the following 12 months and used to identify non-faller, single faller and multiple faller groups. RESULTS: Multiple fallers were found to have significantly different values, when compared to non-fallers, for pelvis onset (p=0.002); mean angular separation in the transverse plane between the head and trunk (p=0.018); peak angular separation in the transverse plane between the trunk and pelvis (p=0.013); and mean angular separation between the trunk and pelvis (p<0.001). CONCLUSIONS: Older adults who subsequently experience multiple falls show a simplified turning pattern to assist in balance control. This may be a predictor for those at increased risk of falling.