The Biomechanics Research and Innovation Challenge: Development, Implementation, Uptake, and Reflections on the Inaugural Program.

Biomechanics as a discipline is ideally placed to increase awareness and participation of girls and women in science, technology, engineering, and mathematics. A nationwide Biomechanics and Research Innovation Challenge (BRInC) centered on mentoring and role modeling was developed to engage high school girls (mentees) and early-mid-career women (mentors) in the field of biomechanics through the completion of a 100-day research and/or innovation project. This manuscript describes the development, implementation, and uptake of the inaugural BRInC program and synthesizes the research and innovation projects undertaken, providing a framework for adoption of this program within the global biomechanics community. Eighty-seven high school girls in years 9 and 10 (age range: 14-16 y) were mentored in teams (n = 17) by women in biomechanics (n = 24). Using a design thinking approach, teams generated solutions to biomechanics-based problem(s)/research question(s). Eight key reflections on program strengths, as well as areas for improvement and planned changes for future iterations of the BRInC program, are outlined. These key reflections highlight the innovation, impact, and scalability of the program; the importance of a program framework and effective communication tools; and implementation of strategies to sustain the program as well as the importance of diversity and building a sense of community.

Effects of multidirectional elastic tape on pain and function in individuals with lateral elbow tendinopathy: A randomised crossover trial.

OBJECTIVE: To investigate the effects of multidirectional elastic tape on pain and function in individuals with lateral elbow tendinopathy. STUDY DESIGN: Randomised crossover trial. SETTING: Biomechanics laboratory. SUBJECTS: 27 participants (11 females, mean (SD) age: 48.6 (11.9) years) with clinically diagnosed lateral elbow tendinopathy of at least six weeks' duration. INTERVENTIONS: Tensioned multidirectional elastic tape applied over the wrist, compared to control tape (untensioned), and no tape conditions. MAIN MEASURES: Pain-free grip strength and pressure pain threshold were recorded at three timepoints for each condition: baseline, post-application, and following an exercise circuit. Change scores were calculated as the post-application or post-exercise value minus baseline. Repeated-measure analyses of variance were used to examine differences between conditions. RESULTS: There were no statistically significant differences in pain-free grip strength between conditions (flexed position: F2,52 = 0.02, p = 0.98; extended position: F2,52 = 2.26, p = 0.12) or across timepoints (post-application vs post-exercise) (flexed position: F1,26 = 0.94, p = 0.34; extended position: F1,26 = 0.79, p = 0.38). Seven participants (26%) increased pain-free grip strength above the minimal detectable change following application of multidirectional elastic tape. There were no statistically significant differences in pressure pain threshold between conditions (affected lateral epicondyle: F1.51,39.17 = 0.54, p = 0.54) or across timepoints (affected lateral epicondyle: F1,26 = 0.94, p = 0.34). CONCLUSION: Tensioned multidirectional elastic tape may not immediately improve pain-free grip strength or pressure pain threshold in our lateral elbow tendinopathy population; however, individual variation may exist.

Pain-free grip strength in individuals with lateral elbow tendinopathy: Between- and within-session reliability of one versus three trials.

BACKGROUND: Pain-free grip strength is an important outcome measure in lateral elbow tendinopathy (LET); yet, the reliability and minimum detectable change (MDC) in functional positions are unknown. PURPOSE: The purpose of this study is to examine the between- and within-session pain-free grip strength reliability and MDC in LET. METHODS: Twenty-three individuals with LET completed three pain-free grip strength trials with the elbow flexed and extended. The first trial and the mean of three trials were analyzed. Between-session data were collected 2-28 days apart. Within-session data were collected 20-30 min apart. RESULTS: Between-session intraclass correlation coefficients (ICCs) were good (ICC2,1 = 0.75) for single trials (flexed), excellent (ICC2,1 = 0.89-0.94) for single trials (extended), and excellent for the mean of three trials (both positions). Within-session ICCs were excellent for single (ICC2,1 = 0.89-0.91) and the mean of three trials (ICC2,3 = 0.96-0.98) in both positions. Between-session flexed MDCs were 133 N (single) versus 90 N (mean) and extended MDCs were 118 N (single) versus 92 N (mean). Within-session flexed MDCs were 79 N (single) versus 52 N (mean) and extended MDCs were 125 N (single) versus 46 N (mean). CONCLUSIONS: Using the mean of three trials is recommended, and clinicians can be confident of true change if between-session differences are >92 N and within-session differences are >52 N.

Effects of multidirectional elastic tape on forearm muscle activity and wrist extension during submaximal gripping in individuals with lateral elbow tendinopathy: A randomised crossover trial.

BACKGROUND: Lateral elbow tendinopathy is associated with changes to forearm muscle activity and wrist posture during gripping. Multidirectional elastic tape is thought to exert a deloading effect on underlying musculotendinous structures, which could potentially alter muscle activity or wrist posture. METHODS: This single-blinded randomised crossover trial compared the immediate effects of tensioned multidirectional elastic tape, untensioned control tape, and no tape, in individuals with lateral elbow tendinopathy. Muscle activity of extensor carpi radialis longus and brevis, extensor carpi ulnaris, and extensor digitorum and wrist extension angle were recorded during a submaximal gripping task. Muscle activity was normalised to the maximum amplitude recorded during maximal grip. Change scores were calculated (post-condition minus baseline). Repeated-measure analyses of variance were used to examine between-condition differences. FINDINGS: 27 participants (16 males, mean age (SD): 48.6 (11.9) years) underwent all conditions. Extensor digitorum muscle activity was reduced during the multidirectional elastic tape, compared to control tape and no tape (MD -5.6% [95%CI: -9.9 to -1.3], MD -5.8% [95%CI: -10.2 to -1.4], respectively). Extensor carpi ulnaris muscle activity was reduced during the multidirectional elastic tape, compared to the control tape (mean difference [MD] -3.2% [95%CI: -5.3 to -1.1]), but increased during the control tape, compared to the no tape (MD 2.9% [95%CI: 0.8 to 5.0]). No differences were observed in extensor carpi radialis brevis or longus muscle activity, or extension wrist angle between conditions. INTERPRETATION: A decreased in extensor carpi ulnaris and extensor digitorum muscle activity during multidirectional elastic tape may be evidence of a deloading effect during submaximal gripping.

An Investigation of Maximal Strength of the Upper Limb Bilaterally in Individuals With Lateral Elbow Tendinopathy: A Systematic Review With Meta-Analysis.

OBJECTIVE: The aim of this study was to investigate whether there is evidence of bilateral upper limb strength deficits in individuals with unilateral lateral elbow tendinopathy (LET). METHODS: The electronic databases Medline via Ovid, PubMed, and Scopus were searched from inception to March 2020. Included studies encompassed maximal strength outcomes of any upper limb and appendicular musculature in individuals with LET and an asymptomatic comparator. Study quality was rated using a modified version of the Epidemiological Appraisal Instrument. Hedges g effect sizes (ES) and 95% CIs were calculated for comparisons of maximal strength in the LET group and an asymptomatic control group. Meta-analysis using a random-effects model was performed when possible. RESULTS: Fourteen studies were included. Quality appraisal resulted in a mean Epidemiological Appraisal Instrument score of 46% (SD = 10%). Meta-analysis revealed strength deficits in shoulder abduction (pooled ES = -0.37 [95% CI = -0.62 to -0.12]) and shoulder external rotation (pooled ES = -0.55 [95% CI = -0.83 to -0.28]) of the symptomatic limb compared with an asymptomatic control group. Meta-analysis also revealed maximal strength deficits in the upper trapezius (pooled ES = -0.26 [95% CI = -0.49 to -0.02]) of the asymptomatic limb compared with an asymptomatic control group. There was also consistent evidence for strength deficits in the serratus anterior, lower trapezius, and wrist extensor muscles and deficits in grip strength of the symptomatic limb as well as strength deficits in the wrist extensor muscles of the asymptomatic limb in individuals with unilateral LET. CONCLUSION: In individuals with LET, there were maximal strength deficits in shoulder abduction, shoulder external rotation, serratus anterior and lower trapezius muscles, and wrist extension, as well as deficits in grip strength of the symptomatic limb compared with an asymptomatic control group. In addition, there appeared to be strength deficits in the upper trapezius muscle, wrist extension, and metacarpophalangeal joint flexion and extension, as well as deficits in grip strength of the asymptomatic limb in individuals with LET compared with an asymptomatic control group. These results suggest bilateral strength deficits. IMPACT: These findings highlight the importance of a thorough physical examination and appropriate strengthening intervention for the upper limb with a focus on shoulder and scapular stabilizers, in addition to forearm muscles, in individuals with LET. LAY SUMMARY: In people with tennis elbow, widespread strength deficits, including weakness of the shoulder, forearm, and wrist muscles, may exist. Interestingly, some of these weaknesses appear on both the affected and the unaffected sides in people with tennis elbow. A physical therapist can help strengthen these areas.

Back squat velocity to assess neuromuscular status of rugby league players following a match.

OBJECTIVES: Back squat mean concentric velocity (MV) and countermovement jump (CMJ) performance were examined in sub-elite rugby league players post-match to monitor changes in neuromuscular status (NMS) from baseline. Relationships between changes in back squat MV and CMJ performance variables were used to compare back squat MV to an established method to monitor NMS. DESIGN: Longitudinal observational design. METHODS: 18 male sub-elite rugby league players (mean±SD, 20.5±2.4 yr; 180.0±6.7cm; 93.3±11.2kg) performed 3 repetitions of CMJ and back squat with an individualised, pre-determined load at -2h (baseline), +30min, +24h, and +48h in relation to a match. Back squat MV, CMJ height, CMJ peak power, and CMJ peak velocity were measured with a linear position transducer. RESULTS: Significant (p<0.05), small to large decreases (ES=0.52-1.24) were observed in back squat MV up to +48h post-match. Significant (p<0.05), small to moderate decreases (ES=0.52-0.70) in CMJ height were also observed up to +24h post-match, returning to baseline at +48h. CMJ peak power and peak velocity post-match changes were not significant compared to baseline (p>0.05). Significant positive correlations were found between changes in back squat MV and CMJ height at +30min (r=0.59; p=0.009) and +48h (r=0.51; p=0.03). CONCLUSIONS: These findings suggest back squat MV may be a suitable alternative or addition to CMJ testing for monitoring NMS in rugby league players.

Validity and Reliability of Using Load-Velocity Relationship Profiles to Establish Back Squat 1 m·s-1 Load.

ABSTRACT: Elsworthy, N, Callaghan, DE, Scanlan, AT, Kertesz, AHM, Kean, CO, Dascombe, BJ, and Guy, JH. Validity and reliability of using load-velocity relationship profiles to establish back squat 1 m·s-1 load. J Strength Cond Res 35(2): 340-346, 2021-Although measuring movement velocity during resistance exercise is being increasingly used to monitor player readiness for competition in team sports, the validity and reliability of using set target velocities has not been examined. This study examined test-retest reliability of the load-velocity relationship during the back squat to predict loads corresponding to a mean velocity of 1 m·s-1 (V1Load), test-retest reliability of mean concentric velocity at V1Load, and criterion validity of mean concentric velocity at V1Load. Twenty-seven resistance-trained male rugby league players completed 2 testing sessions on separate days to establish individualized back squat load-velocity relationship profiles (30, 40, 60, and 80% estimated 1 repetition maximum). Velocity during the back squat was assessed at each load and V1Load derived using individualized linear regression equations. A subset of subjects (n = 18) also performed the back squat at predicted V1Load to examine the test-retest reliability and compare the mean concentric velocity with the predicted target of 1 m·s-1. The mean concentric velocity was consistent across all loads during load-velocity relationship testing (p > 0.05, intraclass correlation coefficient [ICC] ≥0.75, coefficient of variation [CV] ≤5.7%, effect size [ES] ≤0.27), and for predicting V1Load (p = 0.11, ICC = 0.95, CV = 3.9%, ES = 0.11). The mean concentric velocity at V1Load was reliable (ICC = 0.77; CV = 2.6%; ES = 0.39) and not significantly different (p = 0.21) to the target velocity, supporting criterion validity. Individualized load-velocity profiles for the back squat can accurately predict V1Load, and subsequent use of V1Load to assess back squat velocity is valid and reliable. Using V1Load to assess changes in back squat velocity may have application in measuring changes in strength and power or readiness to train.

Therapeutic tape use for lateral elbow tendinopathy: A survey of Australian healthcare practitioners.

BACKGROUND: Lateral elbow tendinopathy (LET) is a common musculoskeletal condition that can be treated with therapeutic tape. However, little is known of taping practices for LET in a clinical setting. OBJECTIVES: To examine Australian healthcare practitioners' taping techniques, clinical reasoning, and information sources regarding therapeutic tape use for LET. DESIGN: Cross-sectional survey. METHODS: An anonymous online survey was distributed between September 2018 and February 2019. Respondents answered questions about demographics, frequency of tape use, techniques, reasons for application, factors influencing clinical decision-making, and information sources, related to tape for LET. RESULTS/FINDINGS: 188 Australian healthcare practitioners completed the survey. The majority of respondents were physiotherapists (n = 132, 70%) with the remainder of respondents being chiropractors (21%), myotherapists (3%), exercise physiologists (3%), or osteopaths (3%). 51% of respondents use tape as part of their management for LET at least half the time. The most popular taping technique used is a transverse band of rigid tape across the forearm (n = 78, 55% of respondents who use tape). The most common reasons for tape application are to reduce pain during occupational tasks (n = 123, 65%), and during sport/hobbies (n = 101, 54%). Respondents predominately rely on experience and patient preference to guide tape use. 63% of all respondents (n = 118) sought information about tape from professional development courses. CONCLUSION: A wide range of tape techniques are used to treat LET, despite limited evidence for efficacy. Justification for tape is largely based on experience and patient preference; with information mostly gained from professional development courses. More research is required to understand the relationship between the evidence and clinical use of tape to treat LET.

Evaluating the immediate effect of forearm and wrist orthoses on pain and function in individuals with lateral elbow tendinopathy: A systematic review.

BACKGROUND: Lateral elbow tendinopathy is associated with pain during gripping, with forearm/wrist orthoses prescribed for treatment. OBJECTIVES: To investigate the immediate effects of forearm and/or wrist orthoses on outcome measures of pain and function in individuals with lateral elbow tendinopathy. DESIGN: Systematic review METHODS: Four electronic databases were searched to identify randomised controlled trials reporting the immediate effects of forearm and/or wrist orthoses on pain and function in individuals with lateral elbow tendinopathy. The quality of evidence was rated from high to very low, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) for the primary outcomes. Where possible, standardised mean difference (SMD) and 95% confidence intervals were calculated to compare post measures between forearm and/or wrist orthoses and control/placebo conditions. RESULTS: The search revealed 1965 studies, of which, seven randomised crossover trials were included. Using the GRADE approach there was low quality evidence revealing a significant decrease in pain during contraction (SMD range -0.65 to -0.83) with forearm orthoses compared to a control/placebo condition. Low quality evidence revealed improvements in pain-free grip strength with the use of a forearm orthosis (SMD range 0.24-0.38), but not maximal grip strength (SMD range 0.14-0.15). Low quality evidence revealed a static wrist orthosis did not improve pain-free grip strength (SMD -0.08) or maximal grip strength (SMD -0.22). CONCLUSION: There is low quality evidence that forearm orthoses can immediately reduce pain during contraction and improve pain-free grip strength but not maximal grip strength in individuals with lateral elbow tendinopathy.

Sticking to the facts: A systematic review of the effects of therapeutic tape in lateral epicondylalgia.

OBJECTIVE: To systematically identify, appraise, and examine evidence regarding the effects of therapeutic tape on pain and function in individuals with lateral epicondylalgia (LE). METHODS: Five electronic databases were systematically searched up to March 2018. Full-text, peer-reviewed, English-language studies were included if they had an LE population, a standalone tape condition, and an outcome related to pain or function. RESULTS: Eight out of 2022 screened studies were included. Three studies demonstrated immediate (i.e. within 1 h) improvements in pain and pain-free grip strength following diamond deloading rigid tape. One study reported immediate improvements in proprioception following transverse rigid tape. The immediate effects of longitudinal kinesiotape were inconsistent. One study reported improvements in pain and pain-free grip strength, while another study reported no effect on pain, strength, or muscle activity. Two studies examined short-term (i.e. within six weeks) kinesiotape application. One study reported two weeks of longitudinal kinesiotape improved pain and maximum grip strength. The other study reported one week of diamond kinesiotape improved patient-reported pain and function, but not maximum grip strength. CONCLUSIONS: In individuals with LE, diamond deloading rigid tape may immediately improve pain and strength. There is conflicting evidence regarding kinesiotape effects in both immediate and short-term timeframes.

Influence of Different Methods to Determine Maximum Heart Rate on Training Load Outcomes in Basketball Players.

Berkelmans, DM, Dalbo, VJ, Fox, JL, Stanton, R, Kean, CO, Giamarelos, KE, Teramoto, M, and Scanlan, AT. Influence of different methods to determine maximum heart rate on training load outcomes in basketball players. J Strength Cond Res 32(11): 3177-3185, 2018-The summated-heart-rate-zones (SHRZ) approach uses heart rate (HR) responses relative to maximum HR (HRmax) to calculate the internal training load (TL). Age-predicted, test-derived, and session-based approaches have all been used to determine HRmax in team sports. The purpose of this study was to determine the effects of using age-predicted, test-derived, and session-based HRmax responses on SHRZ TL in basketball players. Semiprofessional, male basketball players (N = 6) were analyzed during the preparatory training phase. Six age-based approaches were used to predict HRmax including Fox (220 - age); Hossack (206 - [0.567 × age]); Tanaka (208 - [0.7 × age]); Nikolaidis (223 - [1.44 × age]); Nes (211 - [0.64 × age]); and Faff (209.9 - [0.73 × age]). Test-derived HRmax was taken as the highest HR during the Yo-Yo intermittent recovery test (Yo-Yo IRT), whereas session-based HRmax was taken as the higher HR seen during the Yo-Yo IRT or training sessions. Comparisons in SHRZ TL were made at group and individual levels. No significant group differences were evident between SHRZ approaches. Effect size analyses revealed moderate (d = 0.60-0.79) differences between age-predicted, test-derived, and session-based methods across the group and individually in 2 players. The moderate differences between approaches suggest age-predicted, test-derived, and session-based methods to determine HRmax are not interchangeable when calculating SHRZ. Basketball practitioners are encouraged to use individualized HRmax directly measured during field-based tests supplemented with higher HR responses evident during training sessions and games when calculating the SHRZ TL to ensure greatest accuracy.

Decrements in knee extensor and flexor strength are associated with performance fatigue during simulated basketball game-play in adolescent, male players.

This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P < 0.05) related to sprint fatigue in the first half (R = 0.65), with dominant knee flexor strength (R = 0.67) and dominant flexor:extensor strength ratio (R = 0.77) decrement significantly (P < 0.05) associated with sprint decrement across the entire game. Mean knee extensor strength (R = 0.71), dominant knee flexor strength (R = 0.80), non-dominant knee flexor strength (R = 0.75), mean knee flexor strength (R = 0.81), non-dominant flexor:extensor strength ratio (R = 0.71), and mean flexor:extensor strength ratio (R = 0.70) decrement measures significantly (P < 0.05) influenced jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play.

Heart Rate Monitoring in Basketball: Applications, Player Responses, and Practical Recommendations.

Berkelmans, DM, Dalbo, VJ, Kean, CO, Milanovic, Z, Stojanovic, E, Stojiljkovic, N, and Scanlan, AT. Heart rate monitoring in basketball: applications, player responses, and practical recommendations. J Strength Cond Res 32(8): 2383-2399, 2018-The aims of this review were to collate the existing literature encompassing heart rate (HR) monitoring in basketball to (a) identify the applications of HR measurement; (b) report HR responses in male and female players during training and game-play; (c) evaluate use of current HR-based training load models; and (d) provide recommendations for future research and best practice approaches for basketball practitioners. Heart rate monitoring in basketball carries 3 primary applications: (a) monitoring exercise intensity; (b) assessing player fatigue status; and (c) quantifying internal training load. When interpreting the available training and game-play HR data in basketball players, key differences have been observed between playing positions and playing levels. Sex- and age-based differences in HR responses during basketball training and game-play are apparent across separate studies; however, further research exploring HR responses in wider player groups is needed, especially in female and junior players. There is also a lack of research directly comparing player HR responses during training and game-play to ascertain the effectiveness of different drills in preparing players for competition. Heart rate-based models have been frequently used to quantify the internal training load in basketball players, including Banister's Training Impulse (TRIMP), Lucia's TRIMP, and Edwards' Summated-Heart-Rate-Zones (SHRZ). The SHRZ model seems to hold practical advantages and better detect changes in player responses across training cycles compared with other approaches. Practical outcomes of this review center on recommendations for position-specific training plans, drills to promote desired cardiovascular stress, analysis of HR outcome measures, and ideal training load monitoring approaches.

The role of biomaterials in the treatment of meniscal tears.

Extensive investigations over the recent decades have established the anatomical, biomechanical and functional importance of the meniscus in the knee joint. As a functioning part of the joint, it serves to prevent the deterioration of articular cartilage and subsequent osteoarthritis. To this end, meniscus repair and regeneration is of particular interest from the biomaterial, bioengineering and orthopaedic research community. Even though meniscal research is previously of a considerable volume, the research community with evolving material science, biology and medical advances are all pushing toward emerging novel solutions and approaches to the successful treatment of meniscal difficulties. This review presents a tactical evaluation of the latest biomaterials, experiments to simulate meniscal tears and the state-of-the-art materials and strategies currently used to treat tears.

How do rocker-soled shoes influence the knee adduction moment in people with knee osteoarthritis? An analysis of biomechanical mechanisms.

The primary objective was to examine mechanisms behind previously observed changes in the knee adduction moment (KAM) with rocker-soled shoes, in participants sub-grouped according to whether they experienced an immediate decrease, or increase, in peak KAM. In subgroups where frontal plane knee ground reaction force (GRF) lever-arm emerged as a significant predictor, a secondary aim was to examine biomechanical factors that contributed to change in this parameter. Thirty individuals with symptomatic, radiographic knee osteoarthritis (OA) underwent 3D gait analysis in unstable rocker-soled shoes and non-rocker-soled shoes. Multiple regression analyses, within each subgroup, examined relationships between changes in frontal plane knee-GRF lever arm and frontal plane resultant GRF magnitude and changes in peak KAM and KAM impulse between shoe conditions. In the subgroup that decreased peak KAM with rocker-soled shoes (n=23), change in knee-GRF lever arm and frontal plane GRF magnitude at peak KAM together were significant predictors of change in peak KAM; however, only change in mean knee-GRF lever arm significantly predicted change in KAM impulse. Decreased medial GRF magnitude, increased lateral trunk lean towards the stance limb and reduced varus/increased valgus hip-knee-ankle angle were associated with a lower knee-GRF lever arm in this group, with rocker-soled shoes. In contrast, none of the independent variables predicted changes in KAM in the subgroup who increased peak KAM with rocker-soled shoes (n=7).

The sex-specific internal and external demands imposed on players during Ultimate Frisbee game-play.

BACKGROUND: Despite the growing popularity of Ultimate Frisbee (UF) across sexes, the game demands imposed on players have been predominately examined in males. This study aimed to compare the internal and external demands of UF game-play in males and females. METHODS: Male (N.=10) and female (N.=10) recreational UF players competed in separate sex-specific, indoor UF games. Internal responses (blood lactate concentration [BLa-], rating of perceived exertion [RPE], and heart rate [HR]) and external responses (direction-specific and total relative PlayerLoad™ [PL], and estimated equivalent distance [EED]) were measured. Data were analyzed using mixed ANOVAs with Cohen's effect sizes (d). RESULTS: During male game-play, significantly (P<0.01) higher BLa- (d=1.30, large), HR (d=0.40, small), PL (d=0.80-1.24, moderate-large), and EED (d=0.93, moderate) were apparent during the first half compared to the second half in males. During female game-play, a significantly (P<0.001) larger RPE (d=0.93, moderate) was evident during the second compared to the first half. In addition, females exhibited significantly (P<0.05) lower BLa- (d=1.43, large) in the first half and higher medio-lateral PL (d=1.10, moderate) in the second half compared to males. CONCLUSIONS: While similar global responses were observed between sexes across UF game-play, males experienced greater declines in physiological intensity and multi-directional activity than females. These data indicate overlap in game demands and training recommendations across sexes, with activity maintenance a focus, particularly in males.

Impact loading following quadriceps strength training in individuals with medial knee osteoarthritis and varus alignment.

BACKGROUND: Greater impact loading at initial contact is postulated to play a role in the progression of osteoarthritis. Quadriceps weakness is common in individuals with knee osteoarthritis and may contribute to high impact loading. The purpose of this study was to examine the effects of quadriceps strengthening on impact loading parameters. METHODS: Data from 97 individuals with knee osteoarthritis who participated in a randomized clinical trial examining effects of a 12-week quadriceps strengthening program was used to conduct this secondary exploratory analysis. Participants completed a three-dimensional gait assessment within 10% of 1.0m/s from which maximum rate of loading (Body Weight/second), average rate of loading (Body Weight/second), and peak vertical ground reaction force during early stance (Body Weight) were determined. Peak isometric quadriceps strength (Nm/kg) was also assessed. FINDINGS: There was a significant increase in quadriceps strength in the training group (mean change (95%CI): 0.35(0.25, 0.045) Nm/kg, P=0.01) with no change in the control group (mean change (95%CI): 0.03(-0.39, 0.45) Nm/kg, P>0.05). There were no changes in impact loading variables. With data from both groups combined, changes in quadriceps strength explained 3% of variance in the change in maximum rate of loading. Change in quadriceps strength was not predictive of the change in peak vertical ground reaction force or average rate of loading. INTERPRETATIONS: While change in strength was predictive of change in maximal loading rate, this explained only a small proportion of the variance. Future research examining the role parameters such as neuromuscular control play in impact loading are warranted.

Hip biomechanics during stair ascent and descent in people with and without hip osteoarthritis.

Hip osteoarthritis (OA) is often associated with pain and impaired function. Understanding biomechanical alterations in patients with hip OA during challenging activities such as stair use is important to inform treatments. The aim of this study was to determine whether kinematics and kinetics during stair ambulation differed between people with hip OA and healthy controls. Fifteen participants with symptomatic and radiographic hip OA and 15 asymptomatic healthy controls underwent 3-D motion analysis during stair ascent and descent. Trunk, pelvis, and hip kinematics as well as hip kinetics were evaluated. Analyses were performed unadjusted and adjusted for speed and leg length. In both the unadjusted and adjusted analyses, participants with hip OA ascended stairs with less hip range of motion in all three planes and a lower peak external rotation moment compared to controls. In the unadjusted analysis, hip OA participants descended stairs with greater ipsilateral trunk lean, less sagittal plane range of motion, lower peak extension moment, lower peak external rotation moment, and greater hip adduction moment impulse compared to controls. In the adjusted results, peak internal rotation moment and hip adduction moment impulse were greater in hip OA participants compared to controls. Findings show that individuals with hip OA display limited range of hip joint movement, particularly during stair ascent, and overall indicate the use of strategies (e.g., trunk lean; lower peak external rotation moment; higher adduction moment impulse) that implicate altered hip abductor function. Future research is required to further understand the implications of these findings on hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1505-1514, 2017.

Validity and intra-rater reliability of MyJump app on iPhone 6s in jump performance.

OBJECTIVES: Smartphone applications are increasingly used by researchers, coaches, athletes and clinicians. The aim of this study was to examine the concurrent validity and intra-rater reliability of the smartphone-based application, MyJump, against laboratory-based force plate measurements. DESIGN: Cross sectional study. METHODS: Participants completed counter-movement jumps (CMJ) (n=29) and 30cm drop jumps (DJ) (n=27) on a force plate which were simultaneously recorded using MyJump. To assess concurrent validity, jump height, derived from flight time acquired from each device, was compared for each jump type. Intra-rater reliability was determined by replicating data analysis of MyJump recordings on two occasions separated by seven days. RESULTS: CMJ and DJ heights derived from MyJump showed excellent agreement with the force plate (ICC values range from 0.991 for CMJ to 0.993) However mean DJ height from the force plate was significantly higher than MyJump (mean difference: 0.87cm, 95% CI: 0.69-1.04cm). Intra-rater reliability of MyJump for both CMJ and DJ was almost perfect (ICC values range from 0.997 for CMJ to 0.998 for DJ); however, mean CMJ and DJ jump height for Day 1 was significantly higher than Day 2 (CMJ: 0.43cm, 95% CI: 0.23-0.62cm); (DJ: 0.38cm, 95% CI: 0.23-0.53cm). CONCLUSION: The present study finds MyJump to be a valid and highly reliable tool for researchers, coaches, athletes and clinicians; however, systematic bias should be considered when comparing MyJump outputs to other testing devices.