Acute Response to Training after Returning from the Off-Season in Elite Rugby League Athletes.

The purposes of this study were to quantify the physiological response to the initial two-week preseason period in elite male rugby league (RL) athletes, and to determine if a repeated bout effect (RBE) occurs. Eighteen RL players were monitored for the initial two-week preseason period. Blood samples were collected on days (D)1, D2, D4, D5, D8, D9, D11 and D12 to measure creatine kinase (CK). Neuromuscular power was assessed on D1, D5, D8 and D12. During field-based sessions, the external training load was quantified using global positioning system technology, whilst the internal load was quantified using the training impulse and the session rating of perceived exertion. Resistance-based gym session volume was quantified by total repetitions x weight lifted. Perceived measures of fatigue and muscle soreness were assessed on all training days. Two-way (day x week) repeated measures analysis of variance and Bonferroni's corrected post-hoc tests identified significant changes. There were no significant changes in CK activity (649.2 ± 255.0 vs. 673.8 ± 299.1 µL; p = 0.63) or internal training load measures from week 1 to week 2. External training load measures including total distance (4138.1 ± 198.4 vs. 4525.0 ± 169.2 m; p < 0.001) and repeated high-intensity efforts (12.6 ± 1.8 vs. 17.5 ± 1.8 au; p < 0.001) significantly increased in week 2 compared to week 1. Internal training loads and CK activity did not change in response to an increase in external training loads during the initial preseason. The current results provide support for a 'real world' perspective of the RBE phenomenon that may be more applicable for team sport practitioners.

The repeated bout effect of traditional resistance training on cycling efficiency and performance.

PURPOSE: This study examined the repeated bout effect of two resistance training bouts on cycling efficiency and performance. METHODS: Ten male resistance-untrained cyclists (age 38 ± 13 years; height 180.4 ± 7.0 cm; weight 80.1 ± 10.1; kg; VO2max 51.0 ± 7.6 ml.kg-1.min-1) undertook two resistance training bouts at six-repetition maximum. Blood creatine kinase (CK), delayed-onset of muscle soreness (DOMS), counter-movement jump (CMJ), squat jump (SJ), submaximal cycling and time-trial performance were examined prior to (Tbase), 24 (T24) and 48 (T48) h post each resistance training bout. RESULTS: There were significantly lower values for DOMS (p = 0.027) after Bout 2 than Bout 1. No differences were found between bouts for CK, CMJ, SJ and submaximal cycling performance. However, jump height (CMJ and SJ) submaximal cycling measures (ventilation and perceived exertion) were impaired at T24 and T48 compared to Tbase (p < 0.05). Net efficiency during submaximal cycling improved at Bout 2 (23.8 ± 1.2) than Bout 1 (24.3 ± 1.0%). There were no changes in cycling time-trial performance, although segmental differences in cadence were observed between bouts and time (i.e. Tbase vs T24 vs T48; p < 0.05). CONCLUSION: Cyclists improved their cycling efficiency from Bout 1 to Bout 2 possibly due to the repeated bout effect. However, cyclists maintained their cycling completion times during exercise-induced muscle damage (EIMD) in both resistance training bouts, possibly by altering their cycling strategies. Thus, cyclists should consider EIMD symptomatology after resistance training bouts, particularly for cycling-specific technical sessions, regardless of the repeated bout effect.

The Impact of Exercise-Induced Muscle Damage on Various Cycling Performance Metrics: A Systematic Review and Meta-Analysis.

ABSTRACT: Devantier-Thomas, B, Deakin, GB, Crowther, F, Schumann, M, and Doma, K. The impact of exercise-induced muscle damage on various cycling performance metrics: a systematic review and meta-analysis. J Strength Cond Res 38(1): 196-212, 2024-This systematic review and meta-analysis examined the impact of exercise-induced muscle damage (EIMD) on cycling performance. The primary outcome measure was cycling performance, whereas secondary outcome measures included creatine kinase (CK), delayed-onset muscle soreness (DOMS), and muscular contractions. Data were extracted and quantified through forest plots to report on the standardized mean difference and p values. The meta-analysis showed no significant change in oxygen consumption at 24-48 hours (p > 0.05) after the muscle damage protocol, although ventilation and rating of perceived exertion significantly increased (p < 0.05) during submaximal cycling protocols. Peak power output during both sprint and incremental cycling performance was significantly reduced (p < 0.05), but time-trial and distance-trial performance showed no change (p > 0.05). Measures of CK and DOMS were significantly increased (p < 0.05), whereas muscular force was significantly reduced following the muscle-damaging protocols (p < 0.05), confirming that cycling performance was assessed during periods of EIMD. This systematic review showed that EIMD affected both maximal and submaximal cycling performance. Therefore, coaches should consider the effect of EIMD on cycling performance when implementing unaccustomed exercise into a cycling program. Careful consideration should be taken to ensure that additional training does not impair performance and endurance adaptation.

Acute effects of prior conditioning activity on change of direction performance. A systematic review and meta-analysis.

We performed a systematic review and meta-analysis on the acute effects of prior conditioning activity (CA) on change of direction (COD) performance. Eligible studies, involving healthy participants undergoing acute CA with at least one measure of COD performance, were analysed across diverse databases. A total of 34 studies were included for systematic review with 19 studies included for the meta-analysis. The intervention condition resulted in significantly faster (Z = 4.39; standard mean difference [SMD] = 0.49; p < 0.05) COD performance compared with the control condition. Both unloaded and light loaded CA resulted in significantly greater (SMD = 0.58-0.59) COD performance compared to the control condition. Moreover, heavy loaded CA demonstrated a significant but small (SMD = 0.24) improvement in COD performance compared to the control condition. Age and study design had no effect on the overall meta-analysis outcomes. Both males and females exhibited similar moderate effects with CA but only males demonstrated significantly greater COD performance compared to control conditions. Our findings indicate that a range of CA protocols can acutely improve COD performance with unloaded and light-loaded CA resulting in the greatest performance enhancements. These findings will assist practitioners with the design and implementation of appropriate acute CA to improve COD performance.

Skin sensory alteration and kneeling ability following cruciate retaining total knee arthroplasty are not affected by the incision position: A randomised controlled trial of simultaneous bilateral surgery.

PURPOSE: The purpose of this randomised controlled trial was to assess the impact of skin incision location on the patients' ability to kneel. METHODS: A total of 29 patients undergoing bilateral total knee arthroplasty (58 knees) were randomised to receive a lateral or midline incision, with the contralateral limb receiving the alternative option. Cruciate retaining implants were used in all cases by three experienced arthroplasty surgeons. The primary outcome measures assessed functional ability to kneel using an innovative five-point kneeling scale, preferred knee to kneel on and the area of cutaneous sensory loss around the incision at 6 weeks, 6 months and 12 months. Secondary outcome measures were the OKS, KOOS JR, FJS and EQ5D patient reported outcome measures (PROMS), length of surgical scar, overall knee preference and range of motion (ROM). RESULTS: There were no significant differences between the two groups for any primary or secondary outcome measures. Flexion range however, had a significant positive correlation with kneeling score (r = 0.335, p = 0.010). The kneeling score increased at each time point after surgery and was significantly greater at 12 months than preoperatively (2.7 v 3.5, p = 0.015). The area of sensory loss lateral to the incision was significantly less at 6 and 12 months than at 6 weeks (43.6cm2 and 40.1cm2 v 84.1cm2, p < 0.0001). CONCLUSION: The ability to kneel following cruciate retaining total knee arthroplasty is not affected by the incision position but by time and flexion range. TKA improves the ability to kneel by 12 months post-surgery. Sensory loss lateral to the incision reduces with time. LEVEL OF EVIDENCE: Therapeutic Level 2.

Patients with knee osteoarthritis have altered gait and gaze patterns compared to age-matched controls: A pilot study.

PURPOSE: Although knee Osteoarthritis (KOA) sufferers are at an increased risk of falls, possibly due to impaired gait function, the associated gaze behaviour in patients with KOA are largely unknown. Thus, we compared gait and gaze behaviours characteristics between KOA patients and asymptomatic age-matched controls. RESULTS: For Timed Up and Go (TUG) and stair climb tasks, the KOA group demonstrated longer periods of gaze fixations with less frequency of fixations compared to the control group. Conversely, for the Timed up and Go Agility (TUGA) test shorter fixation and frequency patterns were observed. The KOA group presented a shorter final stride length prior to the initiation of the first step in the Stair climb assessment. In addition, for the 30m walk and dual task assessments, the average step length was significantly shorter in the KOA group compared to controls. CONCLUSION: Overall, we found altered gait and gaze behaviours are evident in KOA patients which could relate to their increased falls risk.

The Repeated Bout Effect of Multiarticular Exercises on Muscle Damage Markers and Physical Performances: A Systematic Review and Meta-Analyses.

ABSTRACT: Doma, K, Matoso, B, Protzen, G, Singh, U, and Boullosa, D. The repeated bout effect of multiarticular exercises on muscle damage markers and physical performances: a systematic review and meta-analyses. J Strength Cond Res 37(12): 2504-2515, 2023-This systematic review and meta-analysis compared muscle damage markers and physical performance measures between 2 bouts of multiarticular exercises and determined whether intensity and volume of muscle-damaging exercises affected the outcomes. The eligibility criteria consisted of (a) healthy male and female adults; (b) multiarticular exercises to cause muscle damage across 2 bouts; (c) outcome measures were compared at 24-48 hours after the first and second bouts of muscle-damaging exercise; (d) at least one of the following outcome measures: creatine kinase (CK), delayed onset of muscle soreness (DOMS), muscle strength, and running economy. Study appraisal was conducted using the Kmet tool, whereas forest plots were derived to calculate standardized mean differences (SMDs) and statistical significance and alpha set a 0.05. After screening, 20 studies were included. The levels of DOMS and CK were significantly greater during the first bout when compared with the second bout at T24 and T48 (p < 0.001; SMD = 0.51-1.23). Muscular strength and vertical jump performance were significantly lower during the first bout compared with the second bout at T24 and T48 (p ≤ 0.05; SMD = -0.27 to -0.40), whereas oxygen consumption and rating of perceived exertion were significantly greater during the first bout at T24 and T48 (p < 0.05; SMD = 0.28-0.65) during running economy protocols. The meta-analyses were unaffected by changes in intensity and volume of muscle-damaging exercises between bouts. Multiarticular exercises exhibited a repeated bout effect, suggesting that a single bout of commonly performed exercises involving eccentric contractions may provide protection against exercise-induced muscle damage for subsequent bouts.

Examining the Talent Selection Determinants of Ultimate Frisbee Players Selected Into a National Youth Team.

PURPOSE: The purpose of the study was to examine whether various athletic performances, anthropometric measures, and playing experience differentiate selected and nonselected ultimate Frisbee players trialing to compete in the world championship. METHODS: Forty-three Australian male ultimate Frisbee players (age = 21.2 [1.2] y; height = 1.7 [6.8] m; body mass = 69.7 [8.2] kg; playing experience = 3.5 [1.5] y) participated in a 30-m sprint test, single-leg run-up jump approach (both left [JumpLL], and right leg [JumpRL]) and a stationary bilateral vertical jump (JumpBIL), and change-of-direction speed test. Following a selection camp, players were subdivided according to their selection or nonselection into the team. RESULTS: A multivariate analysis of variance revealed that height, 10-m sprint time, acceleration, JumpLL, JumpRL, and JumpBIL were significantly greater for selected players than nonselected players (P < .05). Area under the curve (AUC) was greatest for JumpRL (AUC = 79%; optimal cutoff value of 37.5 cm, sensitivity and specificity values of 77% and 71%, respectively), JumpLL (AUC = 74%; optimal cutoff 38.5 cm, sensitivity and specificity values 77% and 77%, respectively), and JumpBIL (AUC = 78%; optimal cutoff value of 40.5 cm, sensitivity and specificity values 71% and 79%, respectively). The largest AUC (AUC = 81%; 95% CI 0.66-0.97; P = .001) was found when combining the explanatory variables that demonstrated moderate to large effect sizes (ie, height, playing experience, 10-m sprint, acceleration, JumpLL, JumpRL, and JumpBIL), with sensitivity of 93% and specificity of 71%. CONCLUSION: These athletic performance and anthropometric characteristics differentiating selected and nonselected players may help inform targeted training and player-development strategies.

Intra-Session Reliability of Sprint Performance on a Non-Motorised Treadmill for Healthy Active Males and Females.

This study examined the intra-session reliability of sprint performance on a non-motorized treadmill amongst healthy, active male and female adults. One hundred and twenty participants (males n = 77; females n = 45) completed two familiarization sessions, followed by a third session that consisted of three trials (T1, T2, T3) of maximal sprints (4-s), interspersed by three minutes of recovery. Combining males and females exhibited moderate-to-excellent test-retest reliability (intra-class correlation coefficient, ICC), minimal measurement error (coefficient of variation, CV) and trivial differences between trials (effect size, ES) for speed, power, total work and acceleration (ICC = 0.82-0.98, CV = 1.31-8.45%, ES = 0.01-0.22). The measurement error was improved between comparisons of T1 vs. T2 (CV = 1.62-8.45%, ES = 0.12-0.22) to T2 vs. T3 (CV = 1.31-6.56%, ES = 0.01-0.07) and better for females (CV = 1.26-7.94%, ES = 0.001-0.26) than males (CV = 1.33-8.53%, ES = 0.06-0.31). The current study demonstrated moderate-to-excellent reliability and good-moderate measurement error during a 4-s sprint on a non-motorized treadmill. However, sex had a substantial impact with females exhibiting better values. Practitioners should employ at least two separate trials within a session, in addition to multiple familiarization sessions, to achieve reliable non-motorized treadmill sprint performances.

Image-derived instrumentation vs. conventional instrumentation with 3D planning for glenoid component placement in reverse total shoulder replacements: a randomized controlled trial.

Hypothesis: Glenoid baseplate positioning for reverse total shoulder arthroplasty (rTSA) is important for stability and longevity, with techniques such as image-derived instrumentation (IDI) developed for improving implant placement accuracy. We performed a single-blinded randomized controlled trial comparing glenoid baseplate insertion accuracy with 3D preoperative planning and IDI jigs vs. 3D preoperative planning and conventional instrumentation. Methods: All patients had a preoperative 3D computed tomography to create an IDI; then underwent rTSA according to their randomized method. Repeat computed tomography scans performed at six weeks postoperatively were compared to the preoperative plan to assess for accuracy of implantation. Patient-reported outcome measures and plain radiographs were collected with 2-year follow-up. Results: Forty-seven rTSA patients were included (IDI n = 24, conventional instrumentation n = 23). The IDI group was more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane (P = .01); and exhibited a smaller degree of error when the native glenoid retroversion was >10° (P = .047). There was no difference in patient-reported outcome measures or other radiographic parameters between the two groups. Conclusion: IDI is an accurate method for glenoid guidewire and component placement in rTSA, particularly in the superior/inferior plane and in glenoids with native retroversion >10°, when compared to conventional instrumentation.

The Effects of Pre-conditioning on Exercise-Induced Muscle Damage: A Systematic Review and Meta-analysis.

BACKGROUND: Several studies have utilised isometric, eccentric and downhill walking pre-conditioning as a strategy for alleviating the signs and symptoms of exercise-induced muscle damage (EIMD) following a bout of damaging physical activity. OBJECTIVES: This systematic review and meta-analysis examined the effects of pre-conditioning strategies on indices of muscle damage and physical performance measures following a second bout of strenuous physical activity. DATA SOURCES: PubMed, CINAHL and Scopus. ELIGIBILITY CRITERIA: Studies meeting the PICO (population, intervention/exposure, comparison, and outcome) criteria were included in this review: (1) general population or "untrained" participants with no contraindications affecting physical performance; (2) studies with a parallel design to examine the prevention and severity of muscle-damaging contractions; (3) outcome measures were compared using baseline and post-intervention measures; and (4) outcome measures included any markers of indirect muscle damage and muscular contractility measures. PARTICIPANTS: Individuals with no resistance training experiences in the previous 6 or more months. INTERVENTIONS: A single bout of pre-conditioning exercises consisting of eccentric or isometric contractions performed a minimum of 24 h prior to a bout of damaging physical activity were compared to control interventions that did not perform pre-conditioning prior to damaging physical activity. STUDY APPRAISAL: Kmet appraisal system. SYNTHESIS METHODS: Quantitative analysis was conducted using forest plots to examine standardised mean differences (SMD, i.e. effect size), test statistics for statistical significance (i.e. Z-values) and between-study heterogeneity by inspecting I2. RESULTS: Following abstract and full-text screening, 23 articles were included in this paper. Based on the meta-analysis, the pre-conditioning group exhibited lower levels of creatine kinase at 24 h (SMD = - 1.64; Z = 8.39; p = 0.00001), 48 h (SMD = - 2.65; Z = 7.78; p = 0.00001), 72 h (SMD = - 2.39; Z = 5.71; p = 0.00001) and 96 h post-exercise (SMD = - 3.52; Z = 7.39; p = 0.00001) than the control group. Delayed-onset muscle soreness was also lower for the pre-conditioning group at 24 h (SMD = - 1.89; Z = 6.17; p = 0.00001), 48 h (SMD = - 2.50; Z = 7.99; p = 0.00001), 72 h (SMD = - 2.73; Z = 7.86; p = 0.00001) and 96 h post-exercise (SMD = - 3.30; Z = 8.47; p = 0.00001). Maximal voluntary contraction force was maintained and returned to normal sooner in the pre-conditioning group than in the control group, 24 h (SMD = 1.46; Z = 5.49; p = 0.00001), 48 h (SMD = 1.59; Z = 6.04; p = 0.00001), 72 h (SMD = 2.02; Z = 6.09; p = 0.00001) and 96 h post-exercise (SMD = 2.16; Z = 5.69; p = 0.00001). Range of motion was better maintained by the pre-conditioning group compared with the control group at 24 h (SMD = 1.48; Z = 4.30; p = 0.00001), 48 h (SMD = 2.20; Z = 5.64; p = 0.00001), 72 h (SMD = 2.66; Z = 5.42; p = 0.00001) and 96 h post-exercise (SMD = 2.5; Z = 5.46; p = 0.00001). Based on qualitative analyses, pre-conditioning activities were more effective when performed at 2-4 days before the muscle-damaging protocol compared with immediately prior to the muscle-damaging protocol, or 1-3 weeks prior to the muscle-damaging protocol. Furthermore, pre-conditioning activities performed using eccentric contractions over isometric contractions, with higher volumes, greater intensity and more lengthened muscle contractions provided greater protection from EIMD. LIMITATIONS: Several outcome measures showed high inter-study heterogeneity. The inability to account for differences in durations between pre-conditioning and the second bout of damaging physical activity was also limiting. CONCLUSIONS: Pre-conditioning significantly reduced the severity of creatine kinase release, delayed-onset muscle soreness, loss of maximal voluntary contraction force and the range of motion decrease. Pre-conditioning may prevent severe EIMD and accelerate recovery of muscle force generation capacity.

Efficacy of surgeon-directed suprascapular and axillary nerve blocks in shoulder arthroscopy: a 3-arm prospective randomized controlled trial.

Background: The use of regional anesthesia in shoulder arthroscopy improves perioperative pain control, thereby reducing the need for opioids and their recognized side effects. Occasionally one type of block is not suitable for a patient's anatomy or comorbidities or requires a specially trained anesthetist to safely perform. The primary aim of this study is to compare the efficacy of 3 different nerve blocks for pain management in patients undergoing shoulder arthroscopy. Methods: A 3-arm, blinded, randomized controlled trial in patients undergoing elective, unilateral shoulder arthroscopic procedures between August 2018 and November 2020 was conducted at a single center. One hundred and thirty participants were randomized into 1 of 3 regional anesthesia techniques. The first group received an ultrasound-guided interscalene block performed by an anesthetist (US + ISB). The second group received an ultrasound-guided suprascapular nerve block and an axillary nerve block by an anesthetist (US + SSANB). The final group received a suprascapular nerve block without ultrasound and an axillary nerve block under arthroscopic guidance by an orthopedic surgeon (A + SSANB). Intraoperative pain response, analgesia requirements, and side effects were recorded. Visual analogue pain scores and opioid doses were recorded in the Post Anaesthesia Care Unit (PACU) and daily for 8 days following the procedure. Results: Twelve patients withdrew from the study after randomization, leaving 39 participants in US + ISB, 40 in US + SSANB, and 39 in A + SSANB. The US + ISB group required significantly lower intraoperative opioid doses than US + SSANB and A + SSANB (P < .001) and postoperatively in PACU (P < .001). After discharge from hospital, there were no differences between all groups in daily analgesia requirements (P = .063). There was significantly more nerve complications with 6 patient-reported complications in the US + ISB group (P = .02). There were no reported differences in satisfaction rates between groups (P = .41); however, the A + SSANB group was more likely to report a wish to not have a regional anesthetic again (P = .04). Conclusion: The US + ISB group required lower opioid doses perioperatively; however, there was no difference between groups after discharge from PACU. The analgesia requirements between the US + SSANB and A + SSANB were similar intraoperatively and postoperatively. A surgeon-administered SSANB may be a viable alternative when an experienced regional anesthetist is not available.

The Acute Effect of Various Feedback Approaches on Sprint Performance, Motivation, and Affective Mood States in Highly Trained Female Athletes: A Randomized Crossover Trial.

PURPOSE: This crossover trial compared the effects of varying feedback approaches on sprint performance, motivation, and affective mood states in female athletes. METHODS: Eligibility criteria were being competitive female athletes, where participants completed sprint tests in 4 randomized feedback conditions on grass, including augmented feedback (sprint time; AUG-FB), technical feedback (cues; TECH-FB), a competition-driven drill (CDD) sprinting against an opponent, and a control condition (no feedback; CON). Participants completed a 20-m sprint (maximum sprint), 30-m curved agility sprint, and a repeated sprint ability test, with sprint times, motivation level, and mood states recorded. The participants were blinded from the number of trials during the repeated sprint ability test. RESULTS: About 12 rugby league players completed all feedback conditions. The maximum sprint times were faster for AUG-FB (3.54 [0.16] s) and CDD (3.54 [0.16] s) compared with TECH-FB (3.64 [0.16] s), while there were no differences compared with CON (3.58 [0.17] s). The curved agility sprint times were faster for AUG-FB (5.42 [0.20] s) compared with TECH-FB (5.61 [0.21] s) and CON (5.57 [0.24] s), although CDD (5.38 [0.26] s) produced faster sprint times than TECH-FB. Effort and value were higher with AUG-FB (6.31 [0.68]; 6.53 [0.05]) compared with CON (5.99 [0.60]; 4.75 [2.07]), while CON exhibited lower enjoyment ratings (4.68 [0.95]) compared with other feedback conditions (AUG-FB: 5.54 [0.72]; CDD: 5.56 [0.67]; TECH-FB: 5.60 [0.56]). CONCLUSIONS: Providing AUG-FB prior to sprint tasks enhances more immediate performance outcomes than TECH-FB. AUG-FB also benefited athlete enjoyment, task effort, and coaching value. Female athletes should receive AUG-FB in testing and training environments, to improve immediate physical performance and motivation.

Impact of a 5-Week Individualised Training Program on Physical Performance and Measures Associated with Musculoskeletal Injury Risk in Army Personnel: A Pilot Study.

OBJECTIVE: To examine the feasibility and effect of an individualised and force-plate guided training program on physical performance and musculoskeletal injury risk factors in army personnel. DESIGN: Pre-post, randomised control. METHODS: Fourteen male and five female Australian Army soldiers were randomised into two groups and performed 5-weeks of physical training. The control group (n = 9) completed standard, group-designed, physical training whilst the experimental group (n = 8) completed an individualised training program. Physical (push-ups, multi-stage fitness test, three repetition maximum (3RM) for squat, strict press, deadlift and floor press), occupational (weight-loaded march time), and technological assessments (two-leg and one-leg countermovement jumps (CMJ), one-leg balance, one-arm plank) were conducted prior to and following the training period. Comparisons between groups and changes within groups were conducted via Mann-Whitney U tests. RESULTS: Compared to the control group, the experimental group exhibited a significantly smaller improvement for weight-loaded march time (-0.7% ± 4.0% vs. -5.1% ± 3.0%, p = 0.03) and a greater improvement for deadlift-3RM (20.6% ± 11.9% vs. 8.4% ± 6.8%, p = 0.056). All other outcomes were similar between groups. Visually favourable alterations in the two-leg CMJ profile with no reports of injuries were noted for the experimental group. CONCLUSIONS: Individualised physical training was feasible within an army setting and, for the most part, produced similar physical, occupational and technological performances to that of standard, group-designed physical training. These preliminary results provide a foundation for future research to expand upon and clarify the benefits of individualised training programs on long-term physical performance and injury risk/incidence in active combat army personnel.

Acute Fatigue Responses to Occupational Training in Military Personnel: A Systematic Review and Meta-Analysis.

INTRODUCTION: Military personnel are required to undertake rigorous physical training to meet the unique demands of combat, often leading to high levels of physiological stress. Inappropriate recovery periods with these high levels of physical stress may result in sub-optimal training and increased risk of injury in military personnel. However, no reviews have attempted to examine the magnitude of training-induced stress following military training activities. The aim of this systematic review was to assess the magnitude of physiological stress (physical, hormonal, and immunological) following task-specific training activities in military personnel. METHODS: An extensive literature search was conducted within CINAHL, PubMed, Scopus, SportDiscus, and Web of Science databases with 7,220 records extracted and a total of 14 studies eligible for inclusion and evaluation. Study appraisal was conducted using the Kmet scale. Meta-analysis was conducted via forest plots, with standard mean difference (SMD, effect size) and inter-trial heterogeneity (I2) calculated between before (preactivity) and after (12-96 hours postactivity) military-specific activities for biomarkers of physiological stress (muscle damage, inflammation, and hormonal) and physical performance (muscular strength and power). RESULTS: Military training activities resulted in significant levels of muscle damage (SMD = -1.28; P = .003) and significant impairments in strength and power (SMD = 0.91; P = .008) and testosterone levels (SMD = 1.48; P = .05) up to 96 hours postactivity. There were no significant differences in inflammation (SMD = -0.70; P = .11), cortisol (SMD = -0.18; P = .81), or insulin-like growth factor 1 (SMD = 0.65; P = .07) when compared to preactivity measures. CONCLUSIONS: These findings indicate that assessments of muscle damage, anabolic hormones like testosterone, strength, and power are effective for determining the level of acute stress following military-specific activities. With regular monitoring of these measures, appropriate recovery periods may be implemented to optimize training adaptations and occupational performance, with minimal adverse training responses in military personnel.

Reliability of Force Plate Metrics During Standard Jump, Balance, and Plank Assessments in Military Personnel.

INTRODUCTION: Prevention of musculoskeletal injury is vital to the readiness, performance, and health of military personnel with the use of specialized systems (e.g., force plates) to assess risk and/or physical performance of interest. This study aimed to identify the reliability of one specialized system during standard assessments in military personnel. METHODS: Sixty-two male and ten female Australian Army soldiers performed a two-leg countermovement jump (CMJ), one-leg CMJ, one-leg balance, and one-arm plank assessments using a Sparta Science force plate system across three testing sessions. Sparta Science (e.g., total Sparta, balance and plank scores, jump height, and injury risk) and biomechanical (e.g., average eccentric rate of contraction, average concentric force, and sway velocity) variables were recorded for all sessions. Mean ± SD, intraclass correlation coefficients (ICCs), coefficient of variation, and bias and limits of agreement were calculated for all variables. RESULTS: Mean results were similar between sessions 2 and 3 (P > .05). The relative reliability for the Sparta Science (ICC = 0.28-0.91) and biomechanical variables (ICC = 0.03-0.85) was poor to excellent. The mean absolute reliability (coefficient of variation) for Sparta Science variables was similar to or lower than that of the biomechanical variables during the CMJ (1-10% vs. 3-7%), one-leg balance (4-6% vs. 9-14%), and one-arm plank (5-7% vs. 12-17%) assessments. The mean bias for most variables was small (<5% of the mean), while the limits of agreement varied with most unacceptable (±6-87% of the mean). CONCLUSIONS: The reliability of most Sparta Science and biomechanical variables during standard assessments was moderate to good. The typical variability in metrics documented will assist practitioners with the use of emerging technology to monitor and assess injury risk and/or training interventions in military personnel.

Femoral Component Rotation in Total Knee Arthroplasty Using a Tibia-First, Gap-Balancing, "Functional Alignment" Technique.

BACKGROUND: The purpose of this study was to describe the femoral component rotation in total knee arthroplasty (TKA) using a tibia-first, gap-balancing, "functional alignment" technique. METHODS: Ninety-seven patients with osteoarthritis received a TKA using computer navigation. The tibial resection was performed according to the kinematic alignment (KA) principles, while the femoral rotation was set according to the gap-balancing technique. Preoperative MRIs and intraoperative resection depth data were used to calculate the following rotational axes: the transepicondylar axis (TEA), the posterior condylar axis (PCA) and the prosthetic posterior condylar axis (rPCA). The angles between the PCA and the TEA (PCA/TEA), between the rPCA and the PCA (rPCA/PCA) and between the rPCA and the TEA (rPCA/TEA) were measured. Data regarding patellar maltracking and PROMs were collected for 24 months postoperatively. RESULTS: The mean PCA/TEA, rPCA/TEA and rPCA/PCA angles were -5.1° ± 2.1°, -4.8° ± 2.6° and -0.4° ± 1.7°, respectively (the negative values denote the internal rotation of the PCA to the TEA, rPCA to TEA and rPCA to PCA, respectively). There was no need for lateral release and no cases of patellar maltracking. CONCLUSIONS: A tibia-first, gap-balancing, "functional alignment" approach allows incorporating a gap-balancing technique with kinematic principles. Sagittal complexities in the proximal tibia (variable medial and lateral slopes) can be accounted for, as the tibial resection is completed prior to setting the femoral rotation. The prosthetic femoral rotation is internally rotated relative to the TEA, almost parallel to the PCA, similar to the femoral rotation of the KA-TKA technique. This technique did not result in patellar maltracking.

Repeated Bout Effect of Two Resistance Training Bouts on Bowling-Specific Performance in Male Cricketers.

To examine the repeated bout effect (RBE) following two identical resistance bouts and its effect on bowling-specific performance in male cricketers. Male cricket pace bowlers (N = 10), who had not undertaken resistance exercises in the past six months, were invited to complete a familiarisation and resistance maximum testing, before participating in the study protocol. The study protocol involved the collection of muscle damage markers, a battery of anaerobic (jump and sprint), and a bowling-specific performance test at baseline, followed by a resistance training bout, and a retest of physical and bowling-specific performance at 24 h (T24) and 48 h (T48) post-training. The study protocol was repeated 7-10 days thereafter. Indirect markers of muscle damage were lower (creatine kinase: 318.7 ± 164.3 U·L-1; muscle soreness: 3 ± 1), whilst drop jump was improved (~47.5 ± 8.1 cm) following the second resistance training bout when compared to the first resistance training bout (creatine kinase: 550.9 ± 242.3 U·L-1; muscle soreness: 4 ± 2; drop jump: ~43.0 ± 9.7 cm). However, sport-specific performance via bowling speed declined (Bout 1: -2.55 ± 3.43%; Bout 2: 2.67 ± 2.41%) whilst run-up time increased (2.34 ± 3.61%; Bout 2: 3.84 ± 4.06%) after each bout of resistance training. Findings suggest that while an initial resistance training bout reduced muscle damage indicators and improved drop jump performance following a second resistance training bout, this RBE trend was not observed for bowling-specific performance. It was suggested that pace bowlers with limited exposure to resistance training should minimise bowling-specific practice for 1-2 days following the initial bouts of their resistance training program.

Effect of Exercise Training Programs on Physical Fitness Domains in Military Personnel: A Systematic Review and Meta-Analysis.

INTRODUCTION: Physical training is important to prepare soldiers for the intense occupational demands in the military. However, current physical training may not address all fitness domains crucial for optimizing physical readiness and reducing musculoskeletal injury. The effects of nontraditional military physical training on fitness domains have been inconsistently reported, which limits the design of the ideal training program for performance optimization and injury prevention in the military. The aim of this systematic review was to identify the effects of exercise training on various fitness domains (i.e., aerobic fitness, flexibility, muscular endurance, muscular power, muscular strength, and occupationally specific physical performance) that contribute to occupational performance and musculoskeletal injury risk in military personnel. METHODS: An extensive literature search was conducted in January 2021 and was subsequently updated in July 2021 and December 2021. Included studies consisted of comparative groups of healthy military personnel performing traditional and nontraditional military physical training with at least one assessment representative of a fitness domain. Study appraisal was conducted using the PEDro scale. Meta-analysis was conducted via forest plots, standard mean difference (SMD, effect size), and intertrial heterogeneity (I2). RESULTS: From a total of 7,350 records, 15 studies were identified as eligible for inclusion in this review, with a total of 1,613 participants. The average study quality via the PEDro score was good (5.3/10; range 4/10 to 6/10). Nontraditional military physical training resulted in greater posttraining values for muscular endurance (SMD = 0.46; P = .004; I2 = 68%), power (SMD = 1.57; P < .0001; I2 = 90%), strength via repetition maximum testing (SMD = 1.95; P < .00001; I2 = 91%), and occupationally specific physical performance (SMD = 0.54; P = .007; I2 = 66%) compared to the traditional group. There was no significant difference for aerobic fitness (SMD = -0.31; P = .23; I2 = 86%), flexibility (SMD = 0.58; P = .16; I2 = 76%), and muscular strength via maximal voluntary contraction (SMD = 0.18; P = .28; I2 = 66%) between training groups. CONCLUSIONS: The current systematic review identified that nontraditional military physical training had a greater posttraining effect on muscular endurance, power, strength measured via repetition maximum, and occupationally specific physical performance compared to traditional military physical training. Overall, these findings suggest that nontraditional military physical training may be beneficial in optimizing occupational performance while potentially reducing musculoskeletal injury risk.