IMUs Can Estimate Hip and Knee Range of Motion during Walking Tasks but Are Not Sensitive to Changes in Load or Grade.

The ability to estimate lower-extremity mechanics in real-world scenarios may untether biomechanics research from a laboratory environment. This is particularly important for military populations where outdoor ruck marches over variable terrain and the addition of external load are cited as leading causes of musculoskeletal injury As such, this study aimed to examine (1) the validity of a minimal IMU sensor system for quantifying lower-extremity kinematics during treadmill walking and running compared with optical motion capture (OMC) and (2) the sensitivity of this IMU system to kinematic changes induced by load, grade, or a combination of the two. The IMU system was able to estimate hip and knee range of motion (ROM) with moderate accuracy during walking but not running. However, SPM analyses revealed IMU and OMC kinematic waveforms were significantly different at most gait phases. The IMU system was capable of detecting kinematic differences in knee kinematic waveforms that occur with added load but was not sensitive to changes in grade that influence lower-extremity kinematics when measured with OMC. While IMUs may be able to identify hip and knee ROM during gait, they are not suitable for replicating lab-level kinematic waveforms.

Orthotic interventions for restoring proximal interphalangeal joint motion for patients with hand injuries or conditions: A systematic review and meta-analysis.

BACKGROUND: Limitations to proximal interphalangeal joint (PIPJ) motion can result in significant functional impairment for people with hand injuries and conditions. The role of orthotic intervention to improve PIPJ motion has been studied; however, high-quality systematic reviews and meta-analyses are lacking. PURPOSE: This study aimed to determine the effectiveness of orthotic intervention for restoring PIPJ extension/flexion following hand injuries or conditions. STUDY DESIGN: Systematic review. METHODS: A comprehensive literature search was completed in MEDLINE, CINAHL, Embase, Cochrane Central, and PEDro using terms related to orthoses, finger PIPJ range of motion, and randomized controlled trial design. Methodological quality was assessed using the PEDro score, study outcomes were pooled wherever possible using random effects meta-analysis, and certainty of evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation. RESULTS: Twelve trials were included (PEDro score: 4-7/10). The addition of orthotic intervention was not more effective than hand therapy alone following Dupuytren's release for improving total active extension (mean difference [MD] -2.8°, 95% confidence interval [CI]: -9.6° to 4.0°, p = 0.84), total active flexion (MD -5.8°, 95% CI: -12.7° to 1.2°, p = 0.70), Disability of the Arm, Shoulder and Hand scores (MD 0.4, 95% CI: -2.7 to 3.6, p = 0.79), or patient satisfaction (standardized MD 0.20, 95% CI: -0.49 to 0.09, p = 0.17). Orthotic intervention was more effective than hand therapy alone for improving PIPJ extension for fixed flexion deformities following traumatic finger injury or surgery (MD -16.7°, 95% CI: -20.1° to -13.3°, p < 0.001). No studies evaluated orthotic intervention to improve PIPJ flexion. CONCLUSION: The addition of an extension orthosis following procedures to manage Dupuytren's contracture is no better than hand therapy alone for improving PIPJ extension. In contrast, the addition of a PIPJ extension orthosis in the presence of traumatic PIPJ fixed flexion deformities is more effective for improving PIPJ extension than hand therapy alone. Future studies are needed to evaluate the role of orthotic intervention for improving PIPJ flexion.

Does changing the Functional Movement Screen composite score threshold influence injury risk estimation in junior Australian football players?

This study aimed to identify whether a revised lower Functional Movement Screen (FMS) composite score threshold would be associated with a greater injury risk for junior athletes than the common threshold of≤14. This prospective cohort study included tracking of 809 elite junior male Australian football players for injuries that resulted in a missed game. All athletes completed pre-season FMS testing and a 12-month self-reported retrospective injury questionnaire. Analyses examined the relationship between composite score thresholds of≤14, ≤13, and≤12 and the risk of injury. The relationship between prospective injury and the common composite threshold score of ≤ 14 was dependent on the presence of a recent injury history (relative risk [RR] = 1.45, p = 0.004) in comparison to no recent injury history (RR = 0.98, p = 0.887). Scoring≤12 in the presence of a recent injury history had the greatest diagnostic accuracy but only a trivial increase in injury risk (RR = 1.59, p = 0.001, sensitivity = 0.35, specificity = 0.80, negative and positive likelihood ratios = 0.81 and 1.75). Whilst some small statistical relationships existed between prospective injury and the FMS composite score thresholds, all three thresholds were not associated with a clinically meaningful relationship with prospective injury and were no more effective than retrospective injury for determining athletes at risk of injury.

The use of exercise relative motion orthoses to improve proximal interphalangeal joint motion: A survey of Australian hand therapy practice.

STUDY DESIGN: Cross-sectional online survey. INTRODUCTION: Exercise relative motion (RM) orthoses are prescribed by hand therapists to improve finger motion but there is limited scientific evidence to guide practice. PURPOSE OF THE STUDY: To describe Australian hand therapists' use of exercise RM orthoses to improve PIPJ motion, including trends in orthosis design, prescription, clinical conditions, and their opinions on orthosis benefits and limitations. METHODS: 870 Australian Hand Therapy Association members were sent an electronic survey that included multiple choice, Likert scale and open-ended questions under four subgroups: demographics, design trends, prescription, and therapist opinions. Data analysis consisted of predominantly descriptive statistics and verbatim transcription. RESULTS: 108 Australian therapists completed the survey, over a third with ≥ 20 years of clinical experience. Exercise RM orthoses were prescribed weekly to monthly (82%) for between 2-6 weeks duration (81%) and used during exercise and function (87%). The most common differential MCPJ position was 11-30° extension (98%) or flexion (92%). Four-finger designs were most common for border digits (OR ≥3.4). Exercise RM orthoses were more commonly used for active and extension deficits compared to passive (OR ≥3.7) and flexion deficits (OR ≥1.4), respectively. Clinicians agreed that the orthosis allowed functional hand use (94%), increased non-intentional exercise (98%), and was challenging to use with fluctuating oedema (60%). DISCUSSION: This survey highlights notable clinical trends despite only reaching a small sample of Australian hand therapists. Exercise RM orthoses were frequently being used for active PIPJ extension and flexion deficits. A common MCPJ differential angle was reported, while the number of fingers incorporated into the design depended on the digit involved. Therapists' preferences mostly agreed with the limited available evidence. CONCLUSION(S): This limited survey identified common exercise RM orthosis fabrication and prescription trends amongst Australian therapists. These insights may inform future biomechanical and clinical research on this underexplored topic.

A Minimal Sensor Inertial Measurement Unit System Is Replicable and Capable of Estimating Bilateral Lower-Limb Kinematics in a Stationary Bodyweight Squat and a Countermovement Jump.

This study aimed to validate a 7-sensor inertial measurement unit system against optical motion capture to estimate bilateral lower-limb kinematics. Hip, knee, and ankle sagittal plane peak angles and range of motion (ROM) were compared during bodyweight squats and countermovement jumps in 18 participants. In the bodyweight squats, left peak hip flexion (intraclass correlation coefficient [ICC] = .51), knee extension (ICC = .68) and ankle plantar flexion (ICC = .55), and hip (ICC = .63) and knee (ICC = .52) ROM had moderate agreement, and right knee ROM had good agreement (ICC = .77). Relatively higher agreement was observed in the countermovement jumps compared to the bodyweight squats, moderate to good agreement in right peak knee flexion (ICC = .73), and right (ICC = .75) and left (ICC = .83) knee ROM. Moderate agreement was observed for right ankle plantar flexion (ICC = .63) and ROM (ICC = .51). Moderate agreement (ICC > .50) was observed in all variables in the left limb except hip extension, knee flexion, and dorsiflexion. In general, there was poor agreement for peak flexion angles, and at least moderate agreement for joint ROM. Future work will aim to optimize methodologies to increase usability and confidence in data interpretation by minimizing variance in system-based differences and may also benefit from expanding planes of movement.

Changes in acceleration load as measured by inertial measurement units manifest in the upper body after an extended running task.

The purpose of this study was to investigate the behaviour of physiological load measures as well as ground reaction forces (GRF) and acceleration load during a prolonged running task that simulated the running demands of an intermittent team sport. Nineteen males completed a maximal aerobic fitness test and an extended running protocol across two sessions. Participants wore a portable metabolic system, and four inertial measurement units (IMU), one on each foot, the lower back and upper back. GRF were measured via an instrumented treadmill. Change in metabolic, IMU and GRF variables across five blocks during the running protocol were assessed using a one-way repeated measures ANOVA. The running protocol elicited large increases in heart rate and oxygen consumption over time. No statistically significant changes in any peak impact accelerations were observed. Resultant acceleration area under the curve (AUC) increased at the lower and upper back locations but was unchanged at the foot. GRF active peak but not impact peak increased during the prolonged run. The results of this study indicate that the effect of an extended running task on IMU measures of external mechanical load is manifested in the upper body, and is effectively measured by AUC.

Senior and Junior Rugby League Players Improve Lower-Body Strength and Power Differently During a Rugby League Season.

ABSTRACT: Wade, JA, Fuller, JT, Devlin, PJ, and Doyle, TLA. Senior and junior rugby league players improve lower-body strength and power differently during a rugby league season. J Strength Cond Res 36(5): 1367-1372, 2022-This investigation evaluated lower-body strength and power changes across a rugby league season in elite junior and senior athletes. Twenty-five senior and 20 junior rugby league players performed an isometric midthigh pull and countermovement jump at 3 time points in a National Rugby League training season (mid-preseason, end-preseason, and in-season). Linear fixed-effects models were used to compare isometric midthigh pull force and countermovement jump power between player experience groups (senior vs. junior) across the season phases (mid-preseason vs. end-preseason vs. and in-season). Cohen's effect sizes (ES) with 95% confidence intervals were calculated for pairwise comparisons. For senior players, absolute and relative strength (ES = 0.38, p < 0.007) and power (ES = 0.64, p < 0.008) increases were observed at end-preseason compared with mid-preseason, but there were no changes in-season (ES = 0.02, p > 0.571). For junior players, strength did not change (ES < 0.01, p > 0.738) and absolute power decreased (ES = 0.29, p < 0.014) at end-preseason compared with mid-preseason; large increases were evident for absolute and relative strength (ES = 1.43, p < 0.001) and power (ES = 0.62, p < 0.001) in-season. This research demonstrates senior and junior rugby league players exhibit unique patterns of improvements in lower-body strength and power across different phases of the season. This highlights the importance for training programs to differ between junior and senior athletes and target different physical qualities for both groups at different times of the season, thus providing guidance for strength and conditioning coaches.

Not All Physical Performance Tests Are Related to Early Season Match Running Performance in Professional Rugby League.

ABSTRACT: Glassbrook, DJ, Fuller, JT, Wade, JA, and Doyle, TLA. Not all physical performance tests are related to early season match running performance in professional rugby league. J Strength Cond Res 36(7): 1944-1950, 2022-This study aimed to determine which physical tests correlate with early season running performance. Sixteen professional rugby league players performed the 30-15 intermittent fitness test (IFT), 1.2-km time trial, 1 repetition maximum (RM) barbell back squat, isometric midthigh pull (IMTP), countermovement jump (CMJ), barbell squat jump (SJ), and ballistic bench press throw (BBP). Bivariate Pearson's correlations and linear regression were used to compare physical tests with peak match running intensities recorded by a portable Global Positioning System and represented by peak match velocity and acceleration, as well as peak 1-, 4-, 6-, and 8-minute instantaneous acceleration/deceleration periods of play. Significant (p < 0.05) negative correlations (r = -0.55 to -0.60) were observed between the IFT and relative 1-, 4-, 6-, and 8-minute peaks, and between the relative 1RM back squat and relative 1-, 4-, 6-, and 8-minute peaks. Significant positive correlations (r = 0.52-0.84) were observed between the following physical tests and match performance pairs: IFT and peak acceleration; relative 1RM back squat and peak acceleration; SJ peak power (relative and absolute) and peak acceleration; CMJ peak force (relative and absolute) and peak acceleration; CMJ peak power (relative and absolute) and peak acceleration and 1-, 4-, 6-, and 8-minute peaks; and relative BBP peak power and peak velocity and peak acceleration. The results of this study highlight that not all generic tests of physical qualities are related to peak match running performance and only those with significant correlations are likely to be able to indicate how players may perform during match-play.

Supramaximal Interval Running Prescription in Australian Rules Football Players: A Comparison Between Maximal Aerobic Speed, Anaerobic Speed Reserve, and the 30-15 Intermittent Fitness Test.

ABSTRACT: Collison, J, Debenedictis, T, Fuller, JT, Gerschwitz, R, Ling, T, Gotch, L, Bishop, B, Sibley, L, Russell, J, Hobbs, A, and Bellenger, CR. Supramaximal interval running prescription in Australian Rules Football players: A comparison between maximal aerobic speed, anaerobic speed reserve and the 30-15 intermittent fitness test. J Strength Cond Res 36(12): 3409-3414, 2022-Accurate prescription of supramaximal interval running during Australian Rules Football (AF) preparatory periods is important to facilitate the specific targeting of physiological and neuromuscular adaptation. This study compared the variability in supramaximal interval running performance prescribed by proportion of maximal aerobic speed (MAS), anaerobic speed reserve (ASR), and 30-15 intermittent fitness test (30-15IFT) terminal speed. Seventeen male junior AF players first completed assessments of MAS, ASR, and 30-15IFT in a randomized order. They subsequently performed supramaximal interval running trials (15 seconds on: 15 seconds off until volitional exhaustion) at 120% MAS, 20% ASR, and 95% 30-15IFT in a randomized order. Variability in time to exhaustion (TTE) for each prescription method was calculated as the mean of the square root of the squared difference between the individual value and the mean value, and it was compared via repeated-measures analysis of variance with statistical significance set at p ≤ 0.05. Time to exhaustion during supramaximal interval running was not different between the prescription methods ( p = 0.58). Time to exhaustion residuals were reduced when prescribed by ASR compared with MAS (standardized mean difference [SMD] = -0.47; 29%); however, confidence intervals about this reduction indicated that there was some uncertainty in this finding (SMD = -1.03 to 0.09; p = 0.09). Trivial differences in TTE residuals were present when prescribed by 30-15IFT compared with MAS (SMD = -0.05 ± 0.59; p = 0.86). Although there was some uncertainty about the reduction in supramaximal interval running performance variability when prescribed by ASR compared with MAS, the 29% reduction exceeds the inherent error in TTE efforts (i.e., ∼9-15%) and may thus be considered practically meaningful. Reducing supramaximal interval running performance variability ensures similar physiological demand across individuals, potentially facilitating similar degrees of physiological adaptation.

Prevention strategies to reduce future impact of low back pain: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the evidence from randomised controlled trials (RCTs) on the effectiveness of prevention strategies to reduce future impact of low back pain (LBP), where impact is measured by LBP intensity and associated disability. DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, Embase, CINAHL, PEDro and The Cochrane (CENTRAL) databases from inception to 22 October 2018. ELIGIBILITY CRITERIA: RCTs evaluating any intervention aiming to prevent future impact of LBP, reporting an outcome measure of LBP intensity and/or disability measured at least 3 months post-randomisation, and the intervention group must be compared with a group that received no intervention/placebo or minimal intervention. Trials restricting recruitment to participants with current LBP were excluded. RESULTS: 27 published reports of 25 different trials including a total of 8341 participants fulfilled the inclusion criteria. The pooled results, from three RCTs (612 participants), found moderate-quality evidence that an exercise programme can prevent future LBP intensity (mean difference (MD) -4.50; 95% CI -7.26 to -1.74), and from 4 RCTs (471 participants) that an exercise and education programme can prevent future disability due to LBP (MD -6.28; 95% CI -9.51 to -3.06). It is uncertain whether prevention programmes improve future quality of life (QoL) and workability due to the overall low-quality and very low-quality available evidence. CONCLUSIONS: This review provides moderate-quality evidence that an exercise programme, and a programme combining exercise and education, are effective to reduce future LBP intensity and associated disability. It is uncertain whether prevention programmes can improve future QoL and workability. Further high-quality RCTs evaluating prevention programmes aiming to reduce future impact of LBP are needed.

Combining physical performance and Functional Movement Screen testing to identify elite junior Australian Football athletes at risk of injury.

The Functional Movement Screen (FMS) and physical performance testing are often suggested to be related to sports injury risk. This study explored if the combination of FMS and physical performance testing improved identification of non-contact injury risk over FMS testing alone in an elite junior Australian football cohort. Over a 3-year period, 573 players completed pre-season injury history questionnaires, FMS, physical performance testing (20-m sprint, vertical jump, planned agility testing, and shuttle run test), and subsequent in-season injury surveillance. Results: Neither previous injury or FMS score <14 were related to an increased risk of subsequent injury in isolation. The combination of FMS composite score ≤14 and previous injury moderately increased the risk of injury (Hazard ratio [HR] = 2.22 [1.09-4.54]). None of the physical performance measures improved the ability to predict injuries based on FMS composite score. FMS asymmetry was only associated with injury when combined with previous injury and vertical jump performance. Players with ≥1 FMS asymmetry and history of previous injury experienced a large increase in injury risk when vertical jump was poor (HR = 4.26 [1.35-13.42]) or good (HR = 3.17 [1.08-9.29]). Players with a combination of a good vertical jump, no previous injury, and no FMS asymmetries were also at moderately increased risk of injury (HR = 3.41 [1.11-10.42]). No physical performance tests improved the ability to identify non-contact injury risk using an FMS composite score threshold. However, a U-shaped relationship between vertical jump and injury risk was identified with both poor and good vertical jump height associated with a moderate-large increase in non-contact injury risk in the presence of ≥1 asymmetrical FMS sub-test.

Foot accelerations are larger than tibia accelerations during sprinting when measured with inertial measurement units.

Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIBLeft and TIBRight), and bilateral dorsal foot surfaces (DORLeft and DORRight). Continuous acceleration signal waveform analysis was performed using one-dimensional statistical parametric mapping (1DSPM). Resultant accelerations were greater for DORLeft than TIBLeft for 60% of the gait cycle (p < 0.001) and greater for DORRight than TIBRight for 50% of the gait cycle (p < 0.003). The larger accelerations at the dorsal foot than the tibia can be explained by movement at the ankle joint, and the placement location relative to the hip. The dorsal foot location can be used to effectively measure accelerations and external mechanical load when it is not feasible to place the accelerometer on the tibia, however results between the two locations should not be compared.

A Case Study of Exercise Adherence during Stereotactic Ablative Radiotherapy Treatment in a Previously Active Male with Metastatic Renal Cell Carcinoma.

Stereotactic Ablative Radiotherapy (SABR) is increasingly replacing thoracotomy for resection of lung cancers and oligometastatic lung lesions but it is not known whether exercise can be maintained during SABR, the major side-effect of which is fatigue. This case study describes a 57-year-old male who exercised regularly (above American College of Sports Medicine minimum weekly exercise guidelines) and continued to exercise during SABR for a renal cell metastasis in his left lung. His exercise program included 5x60-minute moderate intensity aerobic exercise sessions and 3x45-minute resistance exercise sessions per week for 12 weeks post-treatment. Cardiorespiratory fitness and strength, as well as self-reported fatigue, depression, anxiety, physical wellbeing and sleep quality were assessed at baseline and fortnightly. Exercise adherence was 98% and no adverse events occurred. Fatigue was elevated from Weeks 2-8, which adversely impacted exercise intensity perception. Minimal changes were observed in cardiorespiratory fitness, depression, anxiety and sleep quality, but strength decreased, and physical wellbeing was improved above baseline levels. This is the first reported clinical case of exercise during SABR for a lung carcinoma. The data suggest that exercise may be feasible for patients undergoing SABR and may improve physical wellbeing. Larger controlled studies are needed to confirm these findings.

Therapeutic effects of aerobic and resistance exercises for cancer survivors: a systematic review of meta-analyses of clinical trials.

OBJECTIVE: To systematically appraise and summarise meta-analyses investigating the effect of exercise compared with a control condition on health outcomes in cancer survivors. DESIGN: Umbrella review of intervention systematic reviews. DATA SOURCES: Web of Science, Scopus, Cochrane Library, CINAHL and MEDLINE databases were searched using a predefined search strategy. ELIGIBILITY CRITERIA: Eligible meta-analyses compared health outcomes between cancer survivors participating in an exercise intervention and a control condition. Health outcomes were cardiovascular fitness, muscle strength, health-related quality of life, cancer-related fatigue and depression. Pooled effect estimates from each meta-analysis were quantified using standardised mean differences and considered trivial (<0.20), small (0.20-0.49), moderate (0.50-0.79) and large (≥0.80). Findings were summarised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. RESULTS: There were 65 eligible articles that reported a total of 140 independent meta-analyses. 139/140 meta-analyses suggested a beneficial effect of exercise. The beneficial effect was statistically significant in 104 (75%) meta-analyses. Most effect sizes were moderate for cardiovascular fitness and muscle strength and small for cancer-related fatigue, health-related quality of life and depression. The quality of evidence was variable according to the GRADE scale, with most studies rated low or moderate quality. Median incidence of exercise-related adverse events was 3.5%. CONCLUSION: Exercise likely has an important role in helping to manage physical function, mental health, general well-being and quality of life in people undergoing and recovering from cancer and side effects of treatment. PROSPERO REGISTRATION NUMBER: CRD42015020194.

The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals.

OBJECTIVE: To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. RESULTS: Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5%; limits of agreement [LOA] ≤4.2%). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2%; LOA ≤11.9%). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2%; LOA ≤23.6%) and fourth metatarsals (ICC ≥0.67; CV ≤9.6%; LOA ≤27.5%). BMD was greatest in the first and second metatarsals (P < 0.01). CONCLUSION: Reliable measurements of BMD were achieved for the first, second and fifth metatarsals.

Effects of a minimalist shoe on running economy and 5-km running performance.

The purpose of this study was to determine if minimalist shoes improve time trial performance of trained distance runners and if changes in running economy, shoe mass, stride length, stride rate and footfall pattern were related to any difference in performance. Twenty-six trained runners performed three 6-min sub-maximal treadmill runs at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes while running economy, stride length, stride rate and footfall pattern were assessed. They then performed a 5-km time trial. In the minimalist shoe, runners completed the trial in less time (effect size 0.20 ± 0.12), were more economical during sub-maximal running (effect size 0.33 ± 0.14) and decreased stride length (effect size 0.22 ± 0.10) and increased stride rate (effect size 0.22 ± 0.11). All but one runner ran with a rearfoot footfall in the minimalist shoe. Improvements in time trial performance were associated with improvements in running economy at 15 km·h(-1) (r = 0.58), with 79% of the improved economy accounted for by reduced shoe mass (P < 0.05). The results suggest that running in minimalist shoes improves running economy and 5-km running performance.

Predicting maximal aerobic speed through set distance time-trials.

PURPOSE: Knowledge of aerobic performance capacity allows for the optimisation of training programs in aerobically dominant sports. Maximal aerobic speed (MAS) is a measure of aerobic performance; however, the time and personnel demands of establishing MAS are considerable. This study aimed to determine whether time-trials (TT), which are shorter and less onerous than traditional MAS protocols, may be used to predict MAS. METHODS: 28 Australian Rules football players completed a test of MAS, followed by TTs of six different distances in random order, each separated by at least 48 h. Half of the participants completed TT distances of 1200, 1600 and 2000 m, and the others completed distances of 1400, 1800 and 2200 m. RESULTS: Average speed for the 1200 and 1400 m TTs were greater than MAS (P < 0.01). Average speed for 1600, 1800, 2000 and 2200 m TTs were not different from MAS (P > 0.08). Average speed for all TT distances correlated with MAS (r = 0.69-0.84; P < 0.02), but there was a negative association between the difference in average TT speed and MAS with increasing TT distance (r = -0.79; P < 0.01). Average TT speed over the 2000 m distance exhibited the best agreement with MAS. CONCLUSIONS: MAS may be predicted from the average speed during a TT for any distance between 1200 and 2200 m, with 2000 m being optimal. Performance of a TT may provide a simple alternative to traditional MAS testing.

Vibration Therapy Is No More Effective Than the Standard Practice of Massage and Stretching for Promoting Recovery From Muscle Damage After Eccentric Exercise.

OBJECTIVE: The purpose of this study was to determine if vibration therapy is more effective than the standard treatment of stretching and massage for improving recovery of muscle strength and reducing muscle soreness after muscle damage induced by eccentric exercise. DESIGN: A randomized, single-blinded parallel intervention trial design was used. SETTING: Research laboratory. PARTICIPANTS: Fifty untrained men aged 18 to 30 years completed the study. INTERVENTIONS: Participants performed 100 maximal eccentric muscle actions (ECCmax) of the right knee extensor muscles. For the next 7 days, 25 participants applied cycloidal vibration therapy to the knee extensors twice daily and 25 participants performed stretching and sports massage (SSM) twice daily. MAIN OUTCOME MEASURES: Changes in markers of muscle damage [peak isometric torque (PIT), serum creatine kinase (CK), and serum myoglobin (Mb)], muscle soreness (visual analog scale), and inflammation [serum C-reactive protein (CRP)] were assessed. RESULTS: After ECCmax, there was no difference in recovery of PIT and muscle soreness or serum CK, Mb, and CRP levels between vibration and SSM groups (P > 0.28). CONCLUSIONS: Cycloidal vibration therapy is no more effective than the standard practice of stretching and massage to promote muscle recovery after the performance of muscle-damaging exercise. CLINICAL RELEVANCE: Prescription of vibration therapy after maximal exercise involving eccentric muscle damage did not alleviate signs and symptoms of muscle damage faster than the standard prescription of stretching and massage.

Sensor location influences the associations between IMU and motion capture measurements of impact landing in healthy male and female runners at multiple running speeds.

This study investigated the relationships between inertial measurement unit (IMU) acceleration at multiple body locations and 3D motion capture impact landing measures in runners. Thirty healthy runners ran on an instrumented treadmill at five running speeds (9-17 km/h) during 3D motion capture. Axial and resultant acceleration were collected from IMUs at the distal and proximal tibia, distal femur and sacrum. Relationships between peak acceleration from each IMU location and patellofemoral joint (PFJ) peak force and loading rate, impact peak and instantaneous vertical loading rate (IVLR) were investigated using linear mixed models. Acceleration was positively related to IVLR at all lower limb locations (p < 0.01). Models predicted a 1.9-3.2 g peak acceleration change at the tibia and distal femur, corresponding with a 10% IVLR change. Impact peak was positively related to acceleration at the distal femur only (p < 0.01). PFJ peak force was positively related to acceleration at the distal (p = 0.03) and proximal tibia (p = 0.03). PFJ loading rate was positively related to the tibia and femur acceleration in males only (p < 0.01). These findings suggest multiple IMU lower limb locations are viable for measuring peak acceleration during running as a meaningful indicator of IVLR.

Just Run: Development of a theory-based motivational online intervention for promoting ongoing running participation.

Running is a popular form of physical activity yet discontinuation is common. Interventions targeting physical activity adoption have shown modest effects, often with little translation into long-term participation, which may limit the health benefits available to the wider community. This paper details the development of a new online running intervention (Just Run) aimed at improving continuation of running activity in new runners through a motivational and psychological lens, including aspects of design, content, refinement, and usability testing. A six-step intervention mapping process was used to develop a theory-based online intervention using a mix of research designs. Key stakeholders including runners, coaches and relevant experts in physical activity and behavior change provided valuable insight, feedback and refinement of the education to be delivered. The final Just Run intervention included ten modules delivered online over twelve weeks to promote ongoing running participation through videos, testimonials, and activities. Key themes identified through the literature and stakeholder engagement process related to goal setting, self-efficacy, intrinsic motivation, social support and overcoming barriers to running participation. Usability testing confirmed the quality and suitability of the education to the target population. Just Run has been developed with a range of stakeholders to address an area of unmet need in the adoption and promotion of running. Just Run is a robust online intervention that has been designed and pre-tested with positive feedback and unique insights from key stakeholders. Further investigation is required to support its implementation to the wider community.