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bOBJECTIVE:/bTo develop a clinical practice guideline covering the assessment, management, and return to work of adults with rotator cuff disorders.bDESIGN:/bClinical practice guideline.bMETHODS:/bUsing systematic reviews, appraisal of the literature, and an iterative approach to obtain consensus from key stakeholders, clinical recommendations and algorithms were developed in the context of the health care system and work environment of the province of Quebec (Canada).bRESULTS:/bRecommendations (n = 73) and clinical decision algorithms (n = 3) were developed to match the objectives. The initial assessment should include the patient's history, a subjective assessment, and a physical examination. Diagnostic imaging is only necessary in select circumstances. Acetaminophen, nonsteroidal anti-inflammatory drugs, and injection therapies may be useful to reduce pain in the short term. Clinicians should prescribe an active and task-oriented rehabilitation program (exercises and education) to reduce pain and disability in adults with rotator cuff disorders. Subacromial decompression is not recommended to treat rotator cuff tendinopathy. Surgery is appropriate for selected patients with a full-thickness rotator cuff tear. A return-to-work plan should be developed early, in collaboration with the worker and other stakeholders, and must combine multiple strategies to promote return to work.bCONCLUSION:/bThis clinical practice guideline was developed to assist the multidisciplinary team of clinicians who provide health care for adults with a rotator cuff disorder. The CPG guides clinical decisionmaking for diagnosis and treatment, and planning for successful return to work.iJ Orthop Sports Phys Ther 2022;52(10):647-664. Epub: 27 July 2022. doi:10.2519/jospt.2022.11306/i.

Study Design Pilot randomized controlled trial with parallel groups. Introduction Engaging individuals with carpal tunnel syndrome (CTS) awaiting carpal tunnel decompression surgery in a preoperative rehabilitation program may mitigate pain and sensorimotor impairments, enhance functional abilities before surgery, and improve postoperative outcomes. Purpose of the Study To assess the feasibility and the efficacy of a novel preoperative neuromobilization exercise program (NEP). Methods Thirty individuals with CTS were randomly allocated into a four-week home-based neuromobilization exercise group or a standard care group while awaiting surgery. Outcome measures included feasibility (ie, recruitment, attrition, adherence, satisfaction, and safety) and efficacy metrics (ie, median nerve integrity and neurodynamics, tip pinch grip, pain, and upper limb functional abilities) collected before (ie, at the baseline and about four weeks later) and four weeks after surgery. Results Thirty individuals with CTS were recruited (recruitment rate = 11.8%) and 25 completed the study (attrition rate = 16.7%). Adherence (94%) and satisfaction with the program (eg, enjoy the exercises and likeliness to repeat the NEP (≥4.2/5) were high and no serious adverse event was reported. NEP-related immediate pre- and post-surgery beneficial effects on pain interference were documented (P = .05, η2 = .10), whereas an overall increased neurodynamics (P = .04, η2 = .11) and decreased pain severity (P = .01, η2 = .21) were observed. Discussion Engaging in the proposed NEP has limited beneficial effect as a stand-alone intervention on pre- and post-surgery outcomes for individuals with CTS. Expanding the program’s content and attribute by adding other components including desensitization maneuvers and novel therapies promoting corticospinal plasticity is recommended. Conclusion A preoperative NEP completed by individuals with CTS awaiting surgery is feasible, acceptable, and safe. However, given the limited beneficial effectsof the program, revision of its content and attributes is recommended before proceeding to large-scale trials.

Purpose There has been much debate regarding the use of intra-articular injections of platelet-rich plasma (PRP) as symptomatic treatment for knee osteoarthritis. The objective of this consensus was to develop guidelines for PRP injections in knee osteoarthritis according to the French National Authority for Health recommendations. Methods Fifteen physicians from different French-speaking countries (10 rheumatologists, 4 specialists in rehabilitation and sports medicine and 1 radiologist) were selected for their expertise in the areas of PRP and osteoarthritis. A comprehensive literature review was conducted on Medline including all published therapeutic trials, open studies, meta-analysis and systematic reviews focusing on the effects of PRP in knee OA, as well as fundamental studies concerning the characteristics of the various types of PRP and their mechanisms, indexed before April 2019. Using the method recommended by the French National Authority for Health inspired by the Delphi consensus process, 25 recommendations were finally retained and evaluated. The recommendations were classified as appropriate or not appropriate, with strong or relative agreement, or uncertain if a consensus was not achieved. Results Among the 25 recommendations selected, the main ones are the following: (1) Intra-articular injections of PRP are an effective symptomatic treatment for early to moderate knee osteoarthritis. This recommendation was considered appropriate with a relative agreement (Median = 8; rank = 6–9). Level of evidence 1A. (2) A PRP treatment sequence in knee osteoarthritis may include 1–3 injections. This recommendation was considered appropriate with a strong agreement (Median = 9; rank = 7–9). Level of evidence 1A. (3) Leucocytes-poor PRP should be preferred in knee osteoarthritis. This recommendation was considered appropriate with a relative agreement (Median = 8; rank = 5–9). Level of evidence 5. (4) Intra-articular PRP knee injections should be performed under ultrasound or fluoroscopic guidance. This recommendation was considered uncertain with no consensus (Median = 8; rank = 3–9). Level of evidence 5. (5) PRP should not be mixed with an anesthetic or intra-articular corticosteroid. This recommendation was considered appropriate with a relative agreement (Median = 9; rank = 6–9). Level of evidence 5 Conclusion Those 25 recommendations should standardize and facilitate the use of IA PRP injections, which are considered by experts as an effective treatment especially in early or moderate knee OA. Although a strong or relative agreement from the experts was obtained for most of the recommendations, many of them had a very low level of evidence (Level 5) and were principally based on the clinical experience of the experts.

Resume L’apparition des plasmas riches en plaquettes dans l’arsenal therapeutique au debut des annees 2000 a ete suivie par un developpement exponentiel de son usage, notamment en pathologie sportive. La Societe francaise de traumatologie du sport a souhaite faire une mise au point des connaissances sur ce sujet et des recommandations pour un bon usage. La composition des PRP utilises en traumatologie sportive est tres heterogene et trop souvent opaque. La consequence est l’entretien d’une confusion et un manque de clarte dans le debat scientifique quant a l’interet de cette technique chez les sportifs. La definition des PRP est rappelee : couche profonde du plasma riche en plaquettes (entre 6 et 9 × 105 PQ/mL) apres centrifugation qui ne doit contenir aucune autre cellule dans toute la mesure du possible (facteurs de la coagulation non actives, leucocytes

This study aimed to examine whether repeated exposures to low (2%) and moderate (4%) exercise-induced hypohydration may reverse the potentially deleterious effect of hypohydration on endurance performance. Using a randomized crossover protocol, ten volunteers (23 years, V˙O2max: 54 mL∙kg−1∙min−1) completed two 4-week training blocks interspersed by a 5-week washout period. During one block, participants replaced all fluid losses (EUH) while in the other they were fluid restricted (DEH). Participants completed three exercise sessions per week (walking/running, 55% V˙O2max, 40 °C): (1) 1 h while fluid restricted or drinking ad libitum, (2) until 2 and (3) 4% of body mass has been lost or replaced. During the first and the fourth week of each training block, participants completed a 12 min time-trial immediately after 2% and 4% body mass loss has been reached. Exercise duration and distance completed (14.1 ± 2.7 vs. 6.9 ± 1.5 km) during the fixed-intensity exercise bouts were greater in the 4 compared to the 2% condition (p < 0.01) with no difference between DEH and EUH. During the first week, heart rate, rectal temperature and perceived exertion were higher (p < 0.05) with DEH than EUH, and training did not change these outcomes. Exercise-induced hypohydration of 2% and 4% body mass impaired time-trial performance in a practical manner both at the start and end of the training block. In conclusion, exercise-induced hypohydration of 2% and 4% body mass impairs 12 min walking/running time-trial, and repeated exposures to these hypohydration levels cannot reverse the impairment in performance.

We investigated the effect of repeated exposures to hypohydration upon cognitive performance. In a randomized crossover design, ten physically active adults completed two 4-week training blocks, one where they maintained euhydration (EUH) and the other where they were water-restricted (DEH) during walking/running at 55% V.O2max, 40 °C. Three sessions per week were performed: (1) 1 h of exercise, (2) exercise until 2% or (3) 4% of body mass has been lost or replaced. Limited to the first and fourth training week, a 12 min walking/running time-trial was completed following the 2 and 4% exercise bouts. Trail making, the Wisconsin card sort, the Stop signal task, Simple visual reaction time and Corsi block-tapping tests were performed immediately following the time-trials. Body mass loss was maintained < 1% with EUH and reached 2.7 and 4.7% with DEH following the time-trials. Except for a lower percentage of correct responses (% accuracy) during the Wisconsin card sort test (p < 0.05) with DEH compared to EUH, no statistically significant decline in cognitive performance was induced by low and moderate levels of hypohydration. Compared to week 1, no statistical differences in cognitive responses were observed after repeated exposures to hypohydration (all p > 0.05). From a practical perspective, the gains in cognitive performance following training to DEH were mostly unclear, but under certain circumstances, were greater than when EUH was maintained. Based on the battery of cognitive tests used in the current study, we conclude that whether physically active individuals are habituated or not to its effect, exercise-induced hypohydration of 2 and 4% has, in general, no or unclear impact on cognitive performance immediately following exercise. These results encourage further research in this area.

Introduction: Achilles tendinopathy (AT) is a chronic musculoskeletal pathology best evaluated by ultrasound imaging. This cross-sectional study aimed at better understanding the relationship between musculoskeletal ultrasound biomarkers (MUBs) of Achilles tendon and localized pain, ankle flexibility, ankle strength, and functional abilities.Method: Forty-one participants with unilateral midportion chronic AT had their tendon images analyzed bilaterally in the longitudinal and transverse planes. The Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A) and Lower Extremity Functional Scale (LEFS) assessed pain and function, respectively, during standing and walking-related activities. Ankle flexibility was evaluated by weight-bearing lunge tests, while ankle isometric peak strength was measured using an instrumented dynamometer. Achilles tendon ultrasonographic images were analyzed using geometric (thickness), composition (echogenicity), and texture (homogeneity) MUBs. Discriminative validity was evaluated using paired Student's t-tests to compare MUBs between symptomatic and asymptomatic sides. Predictive validity was evaluated by computing the Pearson product-moment correlations coefficient between MUBs and pain, ankle flexibility, ankle strength, and function.Results: Significant differences were found in MUBs between the symptomatic and asymptomatic sides, confirming the discriminative validity of the selected MUBs. On the symptomatic side, thickness was found 29.9% higher (p < 0.001), echogenicity 9.6% lower (p < 0.001), and homogeneity 3.8% higher (p = 0.001) when compared with the asymptomatic side. However, predictive validity was scarcely confirmed, as most of the correlation coefficients were found negligible for the associations investigated between MUBs with localized pain, ankle flexibility, strength, and function. Only 14 statistically significant low to moderate associations were found, with negative and positive correlations ranging between −0.31 and −0.55 and between 0.34 and 0.54, respectively.Discussion: Musculoskeletal ultrasound biomarkers have a clinical utility in visualizing in vivo tendon integrity and diagnosing AT. MUBs should be valued as part of a comprehensive neuro-musculoskeletal assessment as they complement pain, flexibility, strength, and function measures. Altogether, they may inform the development and monitoring of a personalized rehabilitation treatment plan.

© 2020 American Congress of Rehabilitation Medicine Objectives: To perform a systematic review of clinical practice guidelines (CPGs) and semantic analysis of specific clinical recommendations for the management of rotator cuff disorders in adults. Data Sources: A systematic bibliographic search was conducted up until May 2018 in Medline, Embase, and Physiotherapy Evidence Database, or PEDro, databases, in addition to 12 clinical guidelines search engines listed on the Appraisal of Guidelines for Research and Evaluation (AGREE) website. Study Selection: Nine CPGs on the management of rotator cuff disorders in adults or workers, available in English or French, and published from January 2008 onward, were included and screened by 2 independent reviewers. Data Extraction: CPG methodology was assessed with the AGREE II checklist. A semantic analysis was performed to compare the strength of similar recommendations based on their formulation. The recommendations were categorized in a standardized manner considering the following 4 levels: “essential,” “recommended,” “may be recommended,” and “not recommended.” Data Synthesis: Methodological quality was considered high for 3 CPGs and low for 6. All CPGs recommended active treatment modalities, such as an exercise program in the management of rotator cuff disorders. Acetaminophen or nonsteroidal anti-inflammatory drug prescriptions and corticosteroid injections were presented as modalities that may be recommended to decrease pain. Recommendations related to medical imagery and surgical opinion varied among the guidelines. The most commonly recommended return-to-work strategies included intervening early, use of a multidisciplinary approach, and adaptation of work organization. Conclusions: Only 3 CPGs were of high quality. The development of more rigorous CPGs is warranted.

Tendon integrity can be described using a wide range of biomarkers via specialized analysis software for images recorded by musculoskeletal ultrasonography. This study proposes a minimal biomarker data set to characterize Achilles tendon ultrasound images and to differentiate between symptomatic and asymptomatic Achilles tendon images. Forty-one individuals with unilateral Achilles tendinopathy and 35 healthy controls had their Achilles tendon images recorded bilaterally by ultrasonography in the longitudinal and transverse planes. A set of 22 biomarkers, organized around three dimensions (geometric, composition and texture), were computed in each plane. A symmetry index, reflecting relative side differences, was compared between groups and analyzed through principal component analysis to isolate biomarkers that best explained data variance. A specific minimal data set was identified by linear regression in the longitudinal (mean thickness, echogenicity, variance and homogeneity at 90°) and transverse (mean thickness, echogenicity and mean homogeneity) planes to characterize and differentiate Achilles tendon integrity.

BACKGROUND Platelet-rich plasma (PRP) has been used to solubilize freeze-dried chitosan (CS) formulations to form injectable implants for tissue repair. OBJECTIVE To determine whether the in vitro performance of the formulations depends on the type of PRP preparation used to solubilize CS. METHODS Formulations containing 1% (w/v) CS with varying degrees of deacetylation (DDA 80.5-84.8%) and number average molar mass (Mn 32-55 kDa), 1% (w/v) trehalose and 42.2 mM calcium chloride were freeze-dried. Seven different PRP preparations were used to solubilize the formulations. Controls were recalcified PRP. RESULTS CS solubilization was achieved with all PRP preparations. CS-PRP formulations were less runny than their corresponding PRP controls. All CS-PRP formulations had a clotting time below 9 minutes, assessed by thromboelastography, while the leukocyte-rich PRP controls took longer to coagulate (>32 min), and the leukocyte-reduced PRP controls did not coagulate in this dynamic assay. In glass culture tubes, all PRP controls clotted, expressed serum and retracted (43-82% clot mass lost) significantly more than CS-PRP clots (no mass lost). CS dispersion was homogenous within CS-PRP clots. CONCLUSIONS In vitro performance of the CS-PRP formulations was comparable for all types of PRPs assessed.

Background Shoulder disorders lead to substantial productivity loss and determinants and predictors of sick leave are poorly known. Objective To perform a systematic review on determinants and predictors of sick leave and delayed return-to-work (RTW) in workers with shoulder disorders. Methods A systematic literature search was conducted and we included studies on workers with shoulder disorders that contained information on determinants or predictors for sick leave or RTW, The risk of bias of included studies was evaluated with a validated tool. Results Eight studies were included and four had a high risk of bias. The only determinants that were found significantly associated with delayed RTW or sickness absence in more than one study were an atraumatic history, disease severity and previous sickness absence. A clinical prediction rule was developed to predict sick leave in one study and included the following predictors: a longer duration of sick leave prior to consultation, higher shoulder pain, strain/overuse in usual activities and psychological complaints. Conclusion Several determinants or predictors were identified in the present review, but there is currently inconsistent evidence on the role of any determinants or predictors of work absence or delayed RTW for workers with a shoulder disorder. More methodologically sound studies are needed.

Background: It is important for clinicians to rely on suitable prognosis factors after hamstring injuries because of the high incidence of these injuries and time away from athletic activities. Purpose: To summarize the current literature on factors that influence return to play after a hamstring injury in athletes. Study Design: Systematic review. Methods: A computer-assisted literature search of CINAHL, MEDLINE, Embase, and EBM Reviews databases (and a manual search of the reference lists of all selected articles) was conducted using keywords related to hamstring injuries and return to play. The literature review criteria included (1) patients with an acute hamstring or posterior thigh injury; (2) a randomized controlled trial, cohort study, case-control study, case series, or prospective or retrospective design; (3) information on rehabilitation, physical therapy, clinical assessment, imaging techniques, and return to play; and (4) studies written in English or French. Results: The search strategy identified 914 potential articles, of which 24 met the inclusion criteria. In terms of the clinical assessment, the following factors were associated with a longer recovery time: stretching-type injuries, recreational-level sports, structural versus functional injuries, greater range of motion deficit with the hip flexed at 90°, time to first consultation >1 week, increased pain on the visual analog scale, and >1 day to be able to walk pain free after the injury. As for magnetic resonance imaging studies, the following factors correlated with a longer recovery time: positive findings; higher grade of injury; muscle involvement >75%; complete transection; retraction; central tendon disruption of the biceps femoris; proximal tendon involvement; shorter distance to the ischial tuberosity; length of the hamstring injury; and depth, volume, and large cross-sectional area. With respect to ultrasound studies, the following factors were associated with a poor prognosis: large cross-sectional area, injury outside the musculotendinous junction, hematoma, structural injury, and injury involving the biceps femoris. Lastly, rehabilitation approaches that included hamstring loading during extensive lengthening or 4 daily sessions of static hamstring stretching led to shorter rehabilitation times. Conclusion: Numerous determinants have an effect on return to play after a hamstring injury in athletes. It is important for sports professionals to be aware of those determinants to guide athletes through the rehabilitation process and refine return-to-play strategies.

This study determined test–retest reliability and minimum detectable change in longitudinal median nerve excursion during upper limb neurodynamic tests (ULNTs). Seven participants with unilateral or bilateral carpal tunnel syndrome and 11 healthy participants were randomly tested with two ULNTs ( i.e ., tensioner and slider). Each ULNT was performed three times each at 45° and 90° of shoulder abduction on two separate visits. Video sequences of median nerve excursion, recorded by a physical therapist using ultrasound imaging, were quantified using computer software. The generalizability theory, encompassing a G-Study and a D-study, measured the dependability coefficient (Φ) along with standard error of measurement (SEM) accuracy and allowed various testing protocols to be proposed. The highest reliability (Φ = 0.84) and lowest minimal measurement error (SEM = 0.58 mm) of the longitudinal median nerve excursion were reached during the ULNT-slider performed with 45° of shoulder abduction and when measures obtained from three different image sequences recorded during a single visit were averaged. It is recommended that longitudinal median nerve excursion measures computed from three separate image sequences recorded during a single visit be averaged in clinical practice. Ideally, adding a second visit (six image sequences) is also suggested in research protocols.

Research has shown early and sustained relief with a combination therapy of a corticosteroid (CS) and hyaluronic acid (HA) in knee osteoarthritis (OA) patients. This can be administered via a single injection containing both products or as separate injections. The former may be more expensive when considering only product cost, but the latter incurs the additional costs and time of a second procedure. The purpose of this study was to compare the cost-utility of the single injection with the 2-injection regimen. The results of this analysis revealed that the single-injection formulation of a CS and HA may be cost-effective, assuming a willingness-to-pay of $50 000 per quality-adjusted life year gained, for symptomatic relief of OA symptoms. This treatment may also be more desirable to patients who find injections to be inconvenient or unpleasant.

BackgroundRotator cuff calcific tendinopathy is characterised by the deposition of hydroxyapatite crystals in one of the rotator cuff tendons and can be managed by ultrasound-guided lavage. However, evidence regarding the efficacy of ultrasound-guided lavage for rotator cuff calcific tendinopathy remains inconclusive. The aim of this systematic review and meta-analysis is to update the available evidence on the efficacy of ultrasound-guided lavage in adults with rotator cuff calcific tendinopathy.MethodsA literature search was conducted up to April 2018 in four bibliographic databases to identify randomised control trials that compared ultrasound-guided lavage alone with other interventions to treat rotator cuff calcific tendinopathy. Randomised control trials were assessed with the Cochrane Risk of Bias Tool. Meta-analyses and/or qualitative synthesis of the evidence were performed.ResultsThree randomised control trials were included. Pooled results for pain (n=226) indicated that ultrasound-guided lavage may significantly decrease pain when compared with shockwave therapy, with a mean difference of −1.98 out of 10 points (95% CI −2.52 to −1.45) in the short term and of −1.84 (95% CI −2.63 to −1.04) in the long term. Based on one trial (n=25), ultrasound-guided lavage significantly improved function when compared with shockwave therapy (pConclusionFor individuals with rotator cuff calcific tendinopathy, low-quality evidence suggests that ultrasound-guided lavage is more effective than shockwave therapy or a corticosteroid injection alone. Future trials could modify the present conclusions.Trial registration numberCRD42018095858.

Background Quantifying the integrity of the Achilles tendon (AT) is a rehabilitation challenge. Adopting quantitative ultrasound measurements (QUS measurements) of the AT could fill this gap by 1) evaluating the test-retest reliability and accuracy of QUS measurements of the AT; 2) determining the best protocol for collecting QUS measurements in clinical practice. Methods A total of 23 ATs with symptoms of Achilles tendinopathy and 63 asymptomatic ATs were evaluated. Eight images were recorded for each AT (2 visits × 2 evaluators × 2 images). Multiple sets of QUS measurements were taken: geometric (thickness, width, area), first-order statistics (computed from a grayscale histogram distribution: echogenicity, variance, skewness, kurtosis, entropy) and texture features (computed from co-occurrence matrices: contrast, energy, homogeneity). A generalizability study quantified the reliability and standard error of measurement (accuracy) of each QUS measurement, and a decision study identified the best measurement taking protocols. Results Geometric QUS measurements demonstrated excellent accuracy and reliability. QUS measurements computed from the grayscale histogram distribution revealed poor accuracy and reliability. QUS measurements derived from co-occurrence matrices showed variable accuracy and moderate to excellent reliability. In clinical practice, using an average of the results of three images collected by a single evaluator during a single visit is recommended. Conclusions The use of geometric QUS measurements enables quantification of AT integrity in clinical practice and research settings. More studies on QUS measurements derived from co-occurrence matrices are warranted.

A recent trial demonstrated that patients with knee osteoarthritis treated with a sodium hyaluronate and corticosteroid combination (Cingal) experienced greater pain reductions compared with those treated with sodium hyaluronate alone (Monovisc) or saline up to 3 weeks postinjection. In this study, injections were administered by 1 of 3 approaches; however, there is currently no consensus on which, if any, of these techniques produce a more favorable outcome. To provide additional insight on this topic, the results of the previous trial were reanalyzed to determine whether (1) the effect of Cingal was significant within each injection technique and (2) pain reductions were similar between injection techniques across all treatment groups. Greater pain reductions with Cingal up to 3 weeks were only significant in the anteromedial subgroup. Across all therapies, both the anteromedial and anterolateral techniques demonstrated significantly greater pain reductions than the lateral midpatellar approach at 18 and 26 weeks.

Exercise-induced dehydration (EID) ≥ 2% bodyweight (BW) impairs endurance performance (EP). It is unclear how pre-exercise hypohydration (PEH), which may impose physiological challenges differing from those of EID, affects EP, VO2 at lactate threshold (VO2LT) and maximal oxygen consumption (VO2max). PURPOSE: To determine the magnitude of the effects of PEH on EP, VO2LT and VO2max using a meta-analytic approach. METHODS: Studies were located via database searches and cross-referencing. Inclusion criteria: BW loss incurred > 1h prior to the exercise tests; hydration level in the control group -1% BW; hypohydration level in the experimental group > 1% BW and > 0.5% than control. Exclusion criteria: diureticsand caloric restriction-induced BW loss. STATISTICS: Random-effect model for mean weighted summary estimates, random-effect (method-of-moments) meta-regression for relationships between variables and analog to the ANOVA for subgroup analyses. Mean changes in EP times during incremental or fixed-power output tests to exhaustion were converted to mean changes in power output. RESULTS: Twenty-nine research articles were retrieved, among which 10, 7 and 7 met the inclusion criteria for EP, VO2LT and VO2max, respectively, providing 14, 10 and 11 effect estimates. Mean BW decreases in all experimental groups were 3.9 ± 0.9% (SD) (range 2.6 to 5.6%). EP and VO2LT: Mean exercise test times among studies was 21 ± 15 min. Mean power output fell by 3.2% (95% CI: 2.4 to 4.0%) and VO2LT by 5.63% (95% CI: 2.8 to 8.4%) in hypohydrated group relative to control. Percent change in power output and VO2LT did not differ between studies with BW losses ≤ 4% or > 4%. Metaregression analyses did not establish significant relationship patterns between BW losses and percent changes in power output or VO2LTs. VO2max: With PEH, VO2max decreased by 2.4% (95% CI: 1.1 to 3.8%) compared with control group. Percent change in VO2max in studies with BW losses ≤ 4% was significantly lower than in those with BW losses > 4%. VO2max was found to decrease by 2.9% for each percent loss in BW above a threshold loss of 3.1% (P = 0.007). CONCLUSIONS: Results indicate that PEH ≥ 3% BW decreases EP (-3%), VO2LT (-6%) and VO2max (-2%) in a significant manner. Studies are required to establish how PEH in the 1-5% BW loss range affects EP during prolonged exercise. BACKGROUND It is well known and widely accepted that exercise-induced dehydration (EID) negatively impacts the capacity to perform prolonged exercise; However, a paucity of research data exists as to how EID influences VO2 at lactate threshold (VO2LT) and maximal oxygen consumption (VO2max); How pre-exercise hypohydration (PEH) affects endurance exercise capacity, VO2LT and VO2max has received some research interest over the past 4 decades; Nevertheless, a clear picture of the effect of PEH on EP, VO2LT and VO2max has yet to be established. OBJECTIVE OF THE STUDY To determine the magnitude of the effects of PEH on EP, VO2LT and VO2max using a meta-analytic approach. METHODS Location of Articles PUBMED and SPORTDiscus database searches and cross referencing from key research articles. The last literature search was completed on October 15, 2009. Inclusion Criteria Bodyweight (BW) loss incurred > 1h prior to the exercise tests; Hydration level in the control group -1% BW; Hypohydration level in the experimental group > 1% BW and > 0.5% than control. Diureticsand caloric restriction-induced BW loss. Exclusion Criteria Computation of the % Changes in VO2LT and VO2max VO2max: Absolute VO2max experimental group (more hypohydrated) absolute VO2max control group (euhydrated or less dehydrated)/absolute VO2max control group * 100; VO2LT: Absolute VO2LT experimental group absolute VO2LT control group/ absolute VO2LT control group * 100. STATISTICS Random-effect model for mean weighted summary estimates; Random-effect meta-regression for relationships between variables and analog to the ANOVA (both method-of-moments technique) for subgroup analyses; Variance and inverse variance calculated for all performance-related variables; When provided, the standard error (SE) of the score differences were used; When not provided, SE was calculated from the exact p value provided; When only p ≤ X was reported, p was considered equal to X, where X is any p value ≤ 0.05; When only p > 0.05 was reported, ES was estimated with the formula (√(SD (A) + SD (B)) – (2 x R x SD (A) x SD (B)))/√N. Where SD is standard deviation. R was taken as 0.89 (average of the results of 4 studies included in the analysis); 95% CIs were calculated and results were considered non-significant when the CI included 0; Unless otherwise notes, results are presented as mean ± SD; All statistics were computed with Comprehensive Meta-Analysis software version 2.2.048, SPSS version 12.0.0 and SPSS macros provided by Dr. David B. Wilson. RESULTS EP and VO2LT Percent change in PO and VO2LT did not differ between studies with BW losses ≤ 4% or > 4%; Meta-regression analyses did not establish significant relationship patterns between BW losses and percent changes in PO or VO2LTs. VO2max Percent change in VO2max in studies with BW losses ≤ 4% was significantly lower than in those with BW losses > 4%; As shown in the Figure below, VO2max was found to decrease by 2.9% for each percent loss in BW above a threshold loss of 3.1% (P = 0.007). CONCLUSIONS Results indicate that PEH ≥ 3% BW decreases EP (-3%), VO2LT (-6%) and VO2max (-2%) in a significant and practically important manner. Studies are required to establish how PEH in the 15% BW range affects EP during prolonged, endurance exercise. Studies are needed to determine whether EID and PEH affect EP in a different manner. ACKNOWLEDGEMENTS As shown in the forest plot below, VO2LT decreased by 5.63 ± 4.5% (95% CI: 2.8 to 8.4%) in hypohydrated group relative to control. The authors wish to thank Dr. Robert Kenefick, Ph.D., and Dr. Samuel Cheuvront, Ph.D., from the USAREIM, for their critical and insightful review of the abstract. Computation of the % Changes in EP Time-trial-type tests with mean power output (PO) provided: POexp POcon/POcon * 100; Time to exhaustion tests: (timeexp timecon/timecon * 100)/(%VO2max/6.4); Incremental tests to exhaustion: (timeexp timecon/timecon * 100) * (1 fraction of the PO the test started). Interpretation of the % Changes in EP A 1% change in PO equals a change of: a) 1% in running time-trial speed or time; b) 0.4% in road cycling time-trial time and; c) 0.3% in rowing-ergometer time-trial time. Mean exercise test times among those studies was 21 ± 15 min; As shown in the forest plot below, mean PO fell by 3.2 ± 1.5% (95% CI: 2.4 to 4.0%) with PEH, compared with the control group. -25 -20 -15 -10 -5 0 5 Change in power output with PEH (%) Caldwell et al. (1984a) Caldwell et al. (1984b) Cheuvront et al. (2005) Dengell et al. (1992a) Dengell et al. (1992b) England et al. (1984) Kenefick et al. (2002) Koslowski et al. (1966) Moquin et al. (2000) Olivier et al. (2007) Saltin et al. (1964a) Saltin et al. (1964b) Saltin et al. (1964c) Webster et al. (1990) Weighted mean effect Black squares represent % changes in PO for each included study. The bars represent the 95% CIs. PEH = Pre-exercise hypohydration. The white diamond represents the weighted mean effect. -30 -25 -20 -15 -10 -5 0 5 10 Change in VO2LT with PEH (%) Caldwell et al. (1984a) Caldwell et al. (1984b) Dengell et al. (1992a) Dengell et al. (1992b) Kenefick et al. (2002) Moquin et al. (2000) Papadopoulos et al. (2008a) Papadopoulos et al. (2008b) Webster et al. (1990) Weighted mean effect England et al. (1989) Black squares represent % changes in VO2LT for each included study. The bars represent 95% CI. PEH= Pre-exercise hypohydration. The white diamond represents the weighted mean effect. As shown in the forest plot below, VO2max decreased by 2.4 ± 2.3% (95% CI: 1.1 to 3.8%) with PEH, relative to control; -25 -20 -15 -10 -5 0 5 10 Change in VO2max with PEH (%) Caldwell et al. (1984a) Caldwell et al. (1984b) Dengell et al. (1992a) Dengell et al. (1992b) Kenefick et al. (2002) Koslowski et al. (1966) Moquin et al. (2000) Saltin et al. (1964a) Saltin et al. (1964b) Saltin et al. (1964c) Webster et al. (1990) Weighted mean effect Black squares represent % changes in VO2max for each included study. The bars represent 95% CI. PEH= Pre-exercise hypohydration. The white diamond represents the weighted mean effect. -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 -6 -5 -4 -3 -2 Bodyweight loss (%) C h a n g e i n V O 2 m a x (% ) y = 2.95x + 9.18, p < 0.01

Vertical jump (VJ) height is a critical aspect of the blocking and attacking performance of the volleyball player. Creatine supplementation (CrS) has been purported to improve jumping performance. However, it has never been previously investigated whether and to which extent CrS affects jumping performance among highly-trained volleyball players. In such athletes with highly-developed jumping abilities the effect of CrS may be more subtle. PURPOSE: To report the results of a pilot study which examined the effect of 4 weeks of CrS on 1 RM VJ attack and repeated VJ block capacity among players of a University level volleyball team. METHODS: All twelve male athletes (age: 22 ± 1.5 yrs; body mass: 84 ± 8 kg) of the Sherbrooke University volleyball team agreed to participate in this study. Using a randomized and double blind protocol, participants were either supplemented with creatine (4-day loading phase + maintenance phase (5g creatine + 30g dextrose/sucrose/day)) or a placebo (dextrose/sucrose only) for 28 days. Participants were familiarized with the blocking and attacking VJ tests. Before and after the interventions, subjects first performed a 1 RM VJ attack test. Then, they completed 10 series of 10 VJ blocks, with a 3 sec interval between jumps and a recovery interval between series of 2 min. STATISTICS: Conventional and magnitude-based inferential statistics were used. RESULTS: Two participants abandoned the study due to injuries and the results of two others were eliminated as they were ± 3 SD outside the sample mean values. CrS did not significantly increase body mass compared with placebo. Over the 100 VJ blocks, CrS increased performance by a mean of 1.9% (95% CI: ± 3.7%, 70% possibly beneficial) compared with placebo. Over the first two VJ block series, the effect of CrS was unclear. For series 3 to 6, mean VJ blocking performance improved with CrS by 2.1% (95% CI: ± 3.6%, 75% possibly beneficial) compared with placebo. With respect to series 7 to 10, CrS increased VJ blocking performance by a mean of 1.7% (95% CI: ± 3.6%, 66% possibly beneficial) compared with placebo. The effect of CrS on 1 RM VJ attack performance was trivial. CONCLUSIONS: Our results indicate that, in volleyball players, CrS is likely to reduce the decay in VJ performance in situations of fatigue and encourage the conduct of further studies on the topic. BACKGROUND Creatine monohydrate has been widely used by athletes and with success for increasing skeletal muscle mass and improving strength, power and anaerobic capacity; Vertical jump (VJ) height is a critical aspect of the blocking and attacking performance of the volleyball player; Creatine supplementation (CrS) has been purported to improve jumping performance; However, it has never been previously investigated whether and to which extent CrS affects jumping performance among highly-trained volleyball players; In such athletes with highly-developed jumping abilities the effect of CrS may be more subtle and therefore difficult to detect; The effect that CrS may have on jumping performance among volleyball players of a same team has never been researched and could provide very important information to coaches. OBJECTIVE OF THE STUDY To report the results of a pilot study in which we examined the effect of 4 weeks of CrS on 1 RM VJ attack and repeated VJ block capacity among players of a University-level volleyball team. With the approbation of the team head coach, all 12 male subjects of the Universite de Sherbrooke volleyball team were recruited and agreed to participate in this pilot study.

A recent systematic review reported that pre-exercise hypohydration (PEH) impairs skeletal muscle performance. The extent to which PEH influences muscular performance-related outcomes remains to be quantified using standard meta-analytic procedures. PURPOSE: To determine the magnitude of the effects of PEH on leg and arm muscle strength, muscle endurance and anaerobic capacity, and jumping ability using a meta-analytic approach. METHODS: Studies were located via database searches and cross-referencing. Inclusion criteria: standard measures of muscular performance; hydration level in the euhydrated control group 1% BW and > 0.5% than control BW. Exclusion criteria: diureticsand caloric restriction-induced BW loss. Results were analyzed using a random-effect model for mean weighted summary effects and a random-effect (method-of-moments) analog to the ANOVA for subgroup analyses. RESULTS: Thirty-seven research articles were retrieved, among which 12, 5, 7 and 5 met the inclusion criteria for muscle strength, muscle endurance, anaerobic capacity and jumping ability, respectively, providing 32, 8, 11 and 16 effect estimates. Mean BW decrease in experimental groups was 3.0 ± 1.3%, 3.2 ± 0.4%, 3.2 ± 1.2% and 2.5 ± 1.2% for muscle strength, muscle endurance, anaerobic capacity and jumping ability, respectively (range: 1.0 to 5.7%). Mean muscle strength fell by 5.2% (95% CI: 3.6 to 6.7%) with PEH relative to control, with leg (5.8%, 95% CI : 3.2 to 8.5%) and arm (4.8%, 95% CI: 2.9 to 6.8%) strength declining similarly. PEH resulted in a mean decrease in muscle endurance of 12.7% (95% CI: 1.7 to 23.7%) and a decline in anaerobic capacity by 5.7% (95% CI: 1.5 to 9.9%). When pooled together, results of studies indicated that the decline in muscular performance is not significantly different between studies with BW losses ≤ or > 3%. PEH did not alter jumping ability compared with control. CONCLUSIONS: PEH of 1.0 to 5.5% BW does not affect jumping ability, but decreases leg (-6%) and arm (-5%) muscle strength, as well as muscle endurance (-13%) and anaerobic capacity (-6%) in a significant and practical manner. BACKGROUND Muscle strength, endurance and anaerobic capacity all play major roles in the athletes’ capacity to perform high-intensity-related exercise; A recent systematic review reported that pre-exercise hypohydration (PEH) impairs skeletal muscle performance; How PEH influences jumping ability has never been systematically evaluated and could have important implications in sports involving jumping movements; The extent to which PEH influences muscular performance-related outcomes remains to be quantified using standard meta-analytic procedures. OBJECTIVE OF THE STUDY To determine the magnitude of the effects of PEH on maximal leg and arm muscle strength, muscle endurance and anaerobic capacity and jumping ability using a meta-analytic approach. METHODS Location of Articles PUBMED and SPORTDiscus database searches and cross referencing from key research articles, especially that of Judelson et al. (Sports. Med., 2007. 37: 907.). The last literature search was completed on May 1, 2010. Inclusion Criteria Standard and recognized measures of muscular performance; Hydration level in the euhydrated control group 1% BW and > 0.5% than control BW. Diureticsand caloric restriction-induced BW loss. Exclusion Criteria Equation for Calculating % Change in Performance % change in performance: Hypohydrated performance (Experimental group) Euhydrated performance (Control group)/Euhydrated performance x 100. STATISTICS Random-effect model for mean weighted summary estimates; Random-effect meta-regression for relationships between variables and analog to the ANOVA (both method-of-moments technique) for subgroup analyses; Variance and inverse variance calculated for all performance-related variables; When provided, the standard error (SE) of the difference between scores was used; When SE not provided, it was calculated from the exact p value provided; When only p ≤ X was reported, p was considered equal to X, where X is any p value ≤ 0.05; When only p > 0.05 was reported, ES was estimated with the formula (√(SD (A) + SD (B)) – (2 x R x SD (A) x SD (B)))/√N. Where SD is standard deviation. R was taken as 0.50; 95% CIs were calculated and results were considered non significant when the CI included 0; Unless otherwise noted, results are presented as mean ± SD; All statistics were computed with Comprehensive Meta-Analysis software version 2.2.048, SPSS version 12.0.0 and SPSS macros provided by Dr. David B. Wilson. RESULTS 37 manuscripts identified: 12, 5, 7 and 5 met the inclusion criteria for muscle strength, muscle endurance, anaerobic capacity and jumping ability, respectively, providing 32, 8, 11 and 16 effect estimates; 180 athletes represented (8% women, 92% men). Age, weight and height of subjects 23 ± 2 yrs, 76 ± 7 kg and 177 ± 5 cm, respectively; Mean sample size was 8 ± 2 subjects; Mean BW decrease across all experimental groups was 3.0 ± 1.2% (range 1.0 to 5.7%); When pooled together, results of studies indicated that the decline in muscular performance was not significantly different between studies with BW losses ≤ or > 3%; Meta-regression results showed no association between % BW loss and any of the performance-related outcomes. Muscle Strength Mean muscle strength fell by 5.2 ± 4.5% (95% CI: 3.6 to 6.7%) with PEH relative to control (Figure 1.) Black and green squares represent % changes in arm and leg strength, respecdtively, for each included study. The blue bars represent 95% CIs. The red diamond represents the weighted mean effect. Mean muscle endurance fell by 12.7 ± 15.9% (95% CI: 1.7 to 23.7%) with PEH, compared with the control group (Figure 3). Figure 1. Black and green squares respectively represent % changes in arm and leg strength for each included study. The blue bars represent 95% CIs. The red diamond represents the weighted mean effect. Muscle Endurance Figure 3. Green squares represent % changes in muscle endurance for each included study. The blue bars represent 95% CIs. The green diamond represents the weighted mean effect. Muscle Anaerobic Capacity Mean muscle anaerobic capacity decreased by 5.7 ± 7.1% (95% CI: 1.5 to 9.9%) with PEH, compared with the control group (Figure 4). Figure 4. Green squares represent % changes in anaerobic capacity for each included study. The green bars represent 95% CIs. The green diamond represents the weighted mean effect. Jumping Ability Mean jumping ability decreased non-significantly by 0.34 ± 3.60% (95% CI: -2.10 to 1.42%) with PEH, compared with the control group. CONCLUSIONS PEH of 1.0 to 5.5% BW does not affect jumping ability, but does impair leg (-6%) and arm (5%) muscle strength, as well as muscle endurance (-13%) and anaerobic capacity (-6%) in a significant and practical manner. ACKNOWLEDGEMENTS -50 -30 -10 10 30 50 Change in muscle strength (%) Weighted mean effect 0 Leg and arm muscle strength declined significantly with PEH, but the extent of the decrease between muscle groups did not differ significantly (P = 0.55) (Figure 2).