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Objective: To examine the specificities and limitations of bilateral and unilateral tasks for the assessment of hip abductor and adductor strength with a commercially-available fixed-frame dynamometer., Design: Correlational/validity study., Methods: Maximal voluntary isometric strength of hip abductors and adductors was evaluated in 130 healthy participants using unilateral and bilateral tasks. Surface EMG activity of agonist and stabilizer muscles was concomitantly recorded in a subgroup of 15 participants., Results: For both muscle groups, bilateral tasks resulted in higher strength values than unilateral tasks (∼25%; p < 0.001). The correlation between left- and right-side data was higher for bilateral than unilateral tasks (p < 0.05), thereby resulting in lower interlimb asymmetries (p < 0.001). Agonist EMG activity was lower for unilateral than bilateral tasks (p < 0.01). Stabilizer EMG activity (external abdominal oblique) was higher for unilateral than bilateral tasks (p < 0.05) on the ipsilateral and contralateral side for hip abductors and adductors, respectively., Conclusions: A large (25%) and quasi-systematic bilateral facilitation of strength was observed for both hip abductors and adductors. Bilateral testing led to an underestimation of interlimb asymmetries, due to higher side equivalence than unilateral tasks. Unilateral testing resulted in lower agonist EMG activity and higher stabilizer activity than bilateral tasks, especially in weaker subjects., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: To investigate the intra-rater reliability and validity of belt-stabilized and tension dynamometry to assess hip muscle strength and power., Design: Repeated measures., Setting: Biomechanics laboratory., Participants: Seventeen uninjured adults (age = 22.0 ± 2.3y; 13 females)., Main Outcomes Measures: Peak torque (strength) and rate of torque development (RTD; power) were measured for hip abduction, internal rotation, external rotation and extension using an isokinetic dynamometer, and belt-stabilized and tension dynamometry., Results: For peak torque assessment, belt-stabilized and tension dynamometry showed good (Intraclass Correlation Coefficient [ICC] = 0.848-0.899) and good-to-excellent (ICC = 0.848-0.942) reliability, respectively. For RTD, belt-stabilized dynamometry showed fair reliability for abduction (ICC = 0.524) and good reliability for hip internal rotation, external rotation, and extension (ICC = 0.702-0.899). Tension dynamometry showed good reliability for all motions when measuring RTD (ICC = 0.737-0.897). Compared to isokinetic dynamometry, belt-stabilized and tension dynamometry showed good-to-excellent correlations for peak torque assessment (r = 0.503-0.870), and fair-to-good correlations for RTD (r = 0.438-0.674). Bland-Altman analysis showed that measures from belt-stabilized and tension dynamometry had clinically meaningful disagreement with isokinetic dynamometry., Conclusion: Tension dynamometry is reliable for assessing hip strength and power in all assessed motions. Belt-stabilized dynamometry is reliable for assessing internal rotation, external rotation, and extension. Validity of both methods is questionable, considering the lack of agreement with isokinetic dynamometry., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Lower limb injury rates have increased dramatically in line with increased female sport participation levels. Muscle strength is a modifiable lower limb injury risk factor, guiding performance monitoring and rehabilitation., Objectives: The aim of this study was to investigate the test-retest reliability of isokinetic and isometric lower limb peak torque to body mass of muscles acting on the hip, knee, and ankle in female team sport athletes. It was hypothesised the test-retest reliability would be good (intraclass correlation coefficients (ICC) ≥ 0.75)., Methods: Thirty-eight female athletes (Australian Rules Football = 18, netball = 12, soccer = 8) aged 16-35 years participated in this study. Participants performed isokinetic (60°/s and 120°/s) and isometric testing on a Biodex Isokinetic Dynamometer on three separate days., Results: Poor to good reliability was demonstrated for all joint movements (ICC = 0.38-0.88) with small to moderate effect sizes (0.00-0.43) and typical errors (5.65-24.49)., Conclusion: Differences in peak torque to body mass were observed between sessions one and two and/or one and three, demonstrating a learning effect. Therefore, three testing sessions, and/or the inclusion of a familiarisation session, is recommended for future assessments in populations unfamiliar with dynamometry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: To verify the effectiveness of the use of a modified position of the Copenhagen Adduction (CA) stage 1 compared to the original position., Design: Cross-sectional study., Setting: Laboratory., Participants: 31 healthy men aged 23.7 ± 1.9 years with no recent or chronic general pathology., Main Outcome Measures: Differences between EMG amplitudes for the adductor longus (AL), rectus femoris (RF) and semi tendinous (ST) during dynamic contractions and adductor maximal isometric voluntary contraction (MIVC) force values between CA stage 1 standard and modified positions were assessed with either Wilcoxon or paired t-test., Results: No significant differences were observed for EMG amplitudes of the AL (p-value = 0.724) and for the RF muscle (p-value = 0.337) and for the adductor force (p-value = 0.361) between the two positions. A significant difference was obtained for the ST (p-value<0.001) mainly explained by the adapted position of the non-dominant leg which unlocked the hip joint and generated less muscle activity in the hamstrings., Conclusions: Muscle activity of the AL muscle and adductor force being similar in both positions, the CA stage 1 modified position could be of interest for rehabilitation after adductor injury or strengthening of the adductors in elite athletes., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Despite the growing interest, information regarding the psychometric properties of maximal voluntary isometric toe plantarflexion force and rate of force development (RFD) is lacking. Hence, we investigate the test-retest reliability and measurement error of these outcome measurement instruments measured with a custom-built dynamometer. Twenty-six healthy adults participated in a crossed design with four sessions separated by 5-7 days. RFD was quantified using manual onset and calculating the impulse and the slope in the following time windows: 0-50 ms, 0-100 ms, 0-150 ms, 0-200 ms, 0-250 ms. We estimated the systematic bias of the mean, the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) from the agreement and consistency models. The ICC and the SEM agreement for maximal voluntary isometric toe plantarflexion force along the perpendicular axis were respectively 0.87 (95%CI: 0.76, 0.93) and 27 N (22, 32), while along the resultant of the perpendicular and anterior posterior axis they were 0.85 (0.73, 0.92) and 29 N (23, 35). The results of the consistency model were similar as the estimated variance for session was closer to zero. A systematic bias of the mean between session 1 and 3 was found. For the RFD variables, the ICC agreement ranged from 0.35 to 0.65. The measurement process was found to be reliable to assess maximal voluntary isometric toe plantarflexion force but not RFD. However, a familiarization session is mandatory and these results need to be confirmed in less coordinated (e.g. aging population) individuals., Competing Interests: Declaration of Competing Interest none., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Assess the validity of hand-held dynamometry (HHD) and the Tindeq Progressor (TP) in assessing peak isometric knee extension torque and limb symmetry index (LSI) versus isokinetic dynamometer (IKD)., Design: Prospective cross-sectional study., Setting: Laboratory., Participants: 31 individuals with unilateral knee disorders (21 female; 28.3 ± 11 years)., Main Outcome Measures: Peak isometric knee extension torque; Knee extension LSI., Results: Strong to almost perfect (p < 0.001) correlations (Cohen's Kappa k) with IKD were found for both devices for peak torque of the uninvolved limb (HHD [k = 0.84], TP [k = 0.91]) and involved limb (HHD [k = 0.93], TP [k = 0.98]). For LSI, moderate to strong (p < 0.001) correlations with IKD were found for HHD (k = 0.79) and TP (k = 0.89). Mean bias errors were equivalent for determining LSI (HHD = 0.02%; TP = 0.03%). Both HHD and TP were highly sensitive (96.2-100.0%) and specific (100.0%) at the 70% LSI threshold. TP showed higher sensitivity and specificity at the 90% LSI threshold., Conclusion: HHD and TP are valid in measuring isometric knee extension torque with the reference standard IKD. TP showed superior validity in identifying LSI. TP also shows greater specificity in identifying the 90% LSI threshold., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: The effects of stretching exercises on muscle strength have been widely researched in the literature, however, there are no studies investigating the effects of Pilates stretching., Objective: To compare the effects of static stretching and Pilates stretching on the concentric muscle strength of the knee extensors and flexors., Method: 102 trained young adults were randomized into three groups: static stretching (n = 33); Pilates stretching (n = 34); control (n = 35). Isokinetic evaluation of the knee extensor and flexor muscles was performed at 60°/s and 180°/s, pre and post acute intervention with stretching. Interventions in the static stretching and Pilates stretching groups occurred in 3 sets x 30 s for each body region considered (a-knee extensor muscles; b-knee flexor muscles). The control group did not perform any intervention., Results: No difference (p > 0.05) was observed between the groups after the intervention. There was only a significant intragroup improvement for the control group on the isokinetic muscle strength of the knee flexors at 180°/s, with a moderate effect size, considering the entire sample (p = 0.040; d = 0.42) and when considering only male gender (p = 0.010; d = 0.60)., Conclusion: Static stretching or Pilates stretching performed as a warm-up did not impair or enhance the concentric muscle strength performance of the knee extensors and flexors. In this way, both forms of stretching can be considered as preparatory exercises before muscle strength training., Competing Interests: Declaration of competing interest The authors Alex Lopes dos Reis, Letícia Siqueira Oliveira, Amanda Priscila Moreno da Silva, Bianca Barbosa, Laís Campos de Oliveira and Raphael Gonçalves de Oliveira declare that there is no potential conflict of interest related to this work., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To indicate the benefits and limitations of the isokinetic test results for the performance of the main shoulder joint movements in swimmers, considering the different competitive levels, swimming techniques, race distances, and sex., Methods: Search on the PubMed, CENTRAL, Medline, LILACS, and SCOPUS databases for the oldest records up to October 2022. Risk of bias, methodological quality, and level of evidence were evaluated based on the NHLBI checklist., Results: 29 articles met the criteria and were included in this study. The quality analysis classified three as "good" and 26 as "regular", with a KAPPA index of 0.87. The main benefits found involved assessments of the clinical condition of the shoulder joint complex, relationships with performance, and reliability studies. The limitations found point to the participant's positioning in the instrument, use of angular velocity above 180°/s, and sample size., Conclusion: The use of the isokinetic dynamometer allows verifying the levels of strength, endurance, balance, and asymmetries among swimmers of different techniques, distances, competitive levels, and sex. Thus, it helps in the analysis and monitoring of the clinical conditions of swimmers' shoulder joints, contributing to the decision-making process of physiotherapists and coaches., Competing Interests: Declaration of competing interest The authors state that there are no conflicts of interest regarding the publication of this review., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: To investigate the connection between the clinical severity of chronic venous insufficiency (CVI) and the biomechanics of the calf muscle pump (CMP)., Material and Methods: Through a cross-sectional observational study, we analyzed women on the age range between 30 and 80 years with chronic venous insufficiency, stratified according to the clinical classification. Ninety-nine women were assessed and classified into groups with different levels of severity: C1 (n = 22); C2 (n = 22); C3 (n = 22); C4 (n = 22); C5 (n = 8); C6 (n = 3). The main purpose was to investigate the strength of the calf muscle pump through total work (TW) and peak torque (PT), and the range of motion (ROM) of the ankle joint. For a secondary analysis, the fatigue index was assessed. All results were run through the Humac®/NORMT isokinetic dynamometer to obtain the data., Results: Our findings pointed out that as the clinical severity of CVI increases, there is a reduction on the PT, the TW, the maximum active ROM and the ROM at 120°/sec. As severity increased, there was a reduction of 24Nm in the TW at 30°/sec.and a reduction of 3Nm in the PT at 30°/sec., Outcomes: When increased, clinical severity of CVI may trigger downgrading in the strength of the CMP and the ROM in the ankle. These findings are of relevance to the clinician, since through these findings, individuals with venous insufficiency may be treated more precisely for each classification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objective: To examine the correlation of Single Leg Bridge Test (SLBT) scores with maximum isometric strength values obtained in handheld dynamometer (HHD) hamstring tests performed in a clinical setting., Design: Cross-sectional study., Setting: Physical therapy clinic., Participants: Fifty healthy and physically active men., Main Outcome Measures: Correlation between SLBT scores and force values found in three HHD hamstring tests: test 'A', volunteer in prone with hip in neutral position and the knee flexed at ∼90°; test 'B', volunteer in supine with hip and knee flexed at ∼90°; and test 'C', volunteer in the same position used to perform the SLBT., Results: The volunteers' SLBT score was 27.55 ± 7.81 repetitions. The SLBT scores were poorly associated with mean (r = 0.246) and peak (r = 0.321) results provided by HHD test 'A'. There were no significant correlations between the SLBT scores and mean or peak values obtained in tests 'B' and 'C' (p > 0.05). Similarly, the SLBT between-limb asymmetry was not associated with asymmetries found in HHD hamstring tests (p > 0.05)., Conclusions: HHD hamstring tests should not be replaced by the SLBT. We recommend for clinicians to applying such tests in a complementary way to assess the hamstring's functional status., Competing Interests: Declaration of competing interest Authors declared no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: Scapular protraction strength can be evaluated using a hand-held dynamometer (HHD). However, it is necessary to measure the reliability of HHD in individuals with shoulder pain and to minimize the limitations related to the evaluator and the low methodological quality cited in previous studies. This study assessed, with methodological enhancement, the intra- and interrater reliability of belt-stabilized HHD in the assessment of scapular protraction strength in individuals with shoulder pain., Method: Fifty individuals with unilateral symptoms of subacromial pain syndrome (20 men, aged 40.5 ± 15.3 years) were evaluated in two sessions using the belt-stabilized HHD for maximum isometric strength of scapular protraction with the individual in the sitting and supine positions. Reliability values were obtained using the intraclass correlation coefficient with the standard error of measurement (SEM and %SEM) and the minimal detectable change (MDC)., Results: The intra- and interrater HHD reliability were excellent for all measurements ranging from 0.88 to 0.96 (SEM = 2.0-4.0 kg; %SEM 12 to 17; MDC = 6-11 kg)., Conclusion: Belt-stabilized HHD is reliable for the assessment of scapular protraction strength in individuals with subacromial pain syndrome in both the sitting and supine positions., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: To investigate changes in angle-specific knee extensor torque between limbs from 4 to 12 months post-anterior cruciate ligament reconstruction(ACLR) in Division I collegiate athletes at two different isokinetic velocities., Design: Case-series study., Setting: Laboratory-based., Participants: Isokinetic knee flexion and extension assessments of 17 athletes (11 female) at 4, 8, and 12 months after ACLR with bone-patellar tendon-bone autograft were evaluated., Main Outcome Measures: Angle-specific curve analyses were performed using statistical parametric mapping for torque data obtained between 14 and 101° at 60°/s and 240°/s velocities., Results: At 60°/s, knee extensor torque of the operated limb increased between 4 and 8 months (18-101°,p < 0.001), 4 and 12 months (28-101°,p < 0.001), and 8 and 12 months post-surgery (62-70°,p = 0.002, and 79-90°,p < 0.001). Knee extensor torque was lower in the operated limb compared to the non-operated limb at 4 (47-97°,p < 0.001) and 8 months (65-90°,p < 0.001) for 60°/s, at 4 (21-89°,p < 0.001) and 8 months (50-77°,p < 0.001) for 240°/s, with no between-limb differences at 12 months post-ACLR for both velocities., Conclusions: Operated limb knee extensor torque increased throughout the majority of knee range of motion from 4 to 12 months post-ACLR at both isokinetic velocities, while non-operated limb torque only improved through a reduced arc of motion in greater knee flexion angles., Competing Interests: Declarations of competing interest No potential conflict of interest was reported by the author(s)., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: The criterion validity of the sphygmomanometer was evaluated, relative to the Force Frame strength testing system. Test-retest reliability was assessed for both hip adduction and abduction strength., Design: Test-retest reliability study and criterion validity study., Participants: 50 asymptomatic, field-sport athletes., Main Outcome Measures: Maximal isometric hip adduction and abduction strength were measured. Interclass correlation coefficient(ICC 2,1 ) with confidence intervals were calculated to evaluate reliability of peak strength values. A Pearson product-moment correlation coefficient(r) was calculated to examine criterion validity of the sphygmomanometer as a measure of force when compared to the ForceFrame., Results: Intra-rater reliability for bilateral adduction testing using both ForceFrame and sphygmomanometer values revealed good-excellent reliability for both the 0° (ICC 2.1  = 0.87-0.90) and 45° (ICC 2.1  = 0.81-0.91) positions. ForceFrame values revealed good-excellent reliability for 0° abduction position and 45° abduction position. A good-moderate relationship (Pearson's r = 0.63) for 0° adduction position, and poor relationship (Pearson's r = 0.40) for 45° adduction position, were found between adduction squeeze values on ForceFrame and sphygmomanometer., Conclusion: Excellent reliability in hip adduction squeeze strength testing for both modes. However, there exists a 'good to moderate'-'fair' relationship between the Force Frame and sphygmomanometer., Competing Interests: Declaration of competing interest None declared., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: To assess the reliability and the validity of a modified version of the Athletic Shoulder Test (M-AST), using a handheld dynamometer instead of a force plate., Design: Test-retest reliability and concordance between tools., Setting: University Motion Lab., Participants: Twenty healthy volunteers who practiced an upper limb sport for at least 5 h per week were recruited for the study., Main Outcome Measures: The concordance between the Athletic Shoulder Test (AST) and the Modified-Athletic Shoulder Test (M-AST) was assessed with intra-class correlation coefficients (ICC), paired T-Test and Bland-Altman plots. The inter-session reliability was assessed with intra-class correlation coefficients (ICC), SEM, MDC and paired T-Test., Results: A strong concordance was found between AST and M-AST values (ICC = 0.86-0.97; p > 0.05) in all the positions considered and for both sessions. Bland-Altman plots confirmed these results. However, the inter-session reliability was more variable for both AST and M-AST (ICC = 0.643-0.923; p < 0.05)., Conclusions: The M-AST seems to be a reliable, cheaper and easier to implement alternative to the AST to measure recovery status following matches or training sessions in upper limb athletes. As for the AST, familiarization trials will have to be performed before the assessment to have accurate measurements., Clinical Trials Registration Number: NCT05112380., Competing Interests: Declaration of competing interest The authors, their immediate families, and any research foundation with which they are affiliated did not receive any financial payments or other benefits from any commercial entity related to the subject of this article., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: The handgrip strength (HGS) is an indicator of muscle strength associated with several health outcomes in adolescents and adults. This cross-sectional study aimed to identify HGS levels and associated modifiable and non-modifiable risk factors in adolescents., Methods: The study included 971 adolescents (496 boys) aged 15-18 years. The HGS was measured by a dynamometer, and the maximum value of right and left hands were summed for a total score. Age, economic status, balanced diet, physical activity, and sedentary behavior were assessed by questionnaires, while body mass index was determined by measuring body weight and height. Multiple linear regression was carried out to examine the association., Results: 65.4% of the adolescents presented low levels of HGS (boys: 73.8%; girls: 56.6%). Low levels of HGS were associated with weight status and height in both sexes. In boys, low levels of HGS were associated with age, balanced diet, physical activity, and sedentary behavior., Conclusion: About six out of ten adolescentes presented low levels of HGS. The main predictors of low levels of HGS in boys were age, physical activity, sedentary behavior, and balanced diet, and weight status and height in both sexes., Competing Interests: Declaration of competing interest Author MAB declares that he has no conflict of interest. Author AAP declares that he has no conflict of interest. Author KSS declares that she has no conflict of interest. Author GSC declares that she has no conflict of interest. Author AP declares that she has no conflict of interest., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Inexpensive and practical equipment to assess muscle strength can disseminate objective measures, which can provide valid information to implement effective treatment and exercise training. The purpose of the study was to examine the instrumental validity of the hanging scale (HS) to assess the muscle strength during knee flexion and extension by comparing the peak force values to a standard equipment (laboratory-grade load cell [LLC]). Knee isometric strength was assessed on thirty-two subjects (16 women and 16 men, 22 [5] years, 171 [9] cm, 69 [15] kg, 23 [4] kg/m 2 ). The knee flexion was tested by placing the volunteer's body in prone with the knee flexed at 90°. Knee extension was assessed with the volunteer seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. No differences were observed comparing the isometric peak forces between a laboratory-grade load cell and a HS (p > 0.05). The intraclass correlation coefficient (ICC) 1,1 returned values above 0.90. The Cronbach's α test also returned values above 0.90 for all comparisons. Bland-Altman results showed high levels of agreement with low risk of bias. The HS appears to be a valid method to assess the knee isometric strength. The portability, the cost-effectiveness and the simple user-friendly system provides an effective way to assess the knee isometric strength., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Fencing is a combat sport, which depends of lower limbs muscular strength and neuromuscular function. Because of that, approximately half of all injuries occur in lower limbs, especially in ankle. Thus, the objective of this study was to verify the influence of a twelve-week proprioceptive training program on ankle muscular strength and muscular balance in fencers., Methods: The study was a clinical trial, with 19 fencing athletes from 14 to 35-year-old. The main outcome was ankle invertors, evertors, plantiflexors and dorsiflexors muscular strength and ankle muscle balance. The study was performed in six stages: familiarization of muscular strength test in isokinetic dynamometer; pre-intervention; intervention; post-intervention; three- and six-months follow-up. At pre-intervention stage, the muscular strength was evaluated. At intervention stage, the athletes performed 12-week proprioceptive training program, three times a week. At post-intervention, three- and the six-months follow-ups, same pre-intervention test was performed., Results: The proprioceptive training improved front leg ankle dorsiflexor strength at three- and six-months follow-ups compared to pre-intervention. Furthermore, training increased the front leg dorsiflexors/plantiflexors conventional ratio at three- and six-months follow-ups compared to pre-intervention; and evertors/invertors conventional ratio at three-months follow-up compared to pre-intervention; and evertors/invertors functional ratio at post-intervention and three- and six-months follow-ups compared to pre-intervention., Conclusions: The improvement and/or maintenance of ankle muscle strength occurred in intervention group seems to be due to stimulus provided by proprioceptive training, with ankle dorsiflexors being the most stimulated group., Competing Interests: Declaration of competing interest There are any perceived financial conflicts of interest related to the research reported in the manuscript., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: To compare the effectiveness of adding anteromedial versus posterolateral hip musculature strengthening to knee strengthening in women with patellofemoral pain (PFP)., Design: Randomized controlled trial., Setting: University physiotherapy clinic., Participants: Fifty-two women with PFP were randomized to receive either anteromedial (AMHG) or posterolateral (PLHG) hip musculature strengthening., Main Outcome Measures: The primary outcomes were pain intensity by the numeric pain rating scale and function by the Anterior Knee Pain Scale in six weeks. Secondary outcomes were pain and function at six months, global perceived effect at six weeks and six months, pain in step down, isometric torque of abductors, adductors and hip rotators measured with hand-held dynamometer, and dynamic knee valgus by step down in six weeks., Results: Both groups showed improvement in primary outcomes; however, no differences were found between groups in pain intensity and function in six weeks and the secondary outcomes. Group x time interaction found superior gains in abductor strength in the PLHG and increase in the strength of the adductors and internal rotators in AMHG., Conclusion: There was no difference between the addition of anteromedial or posterolateral hip musculature strengthening to knee strengthening in improving pain and function in women with PFP., Competing Interests: Declaration of competing interest None declared., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: To determine the validity, intra- and inter-rater, and absolute reliability of a return to sport testing battery for the shoulder in a healthy cohort., Design: Cross-sectional design. All participants completed a battery of strength (isokinetic, isometric, and repetition to failure) and functional assessments on two occasions. Concurrent validity to isokinetic testing was assessed, and intra-rater, inter-rater, and absolute reliability were established for all assessments., Setting: Controlled clinical environment., Participants: Thirty healthy adults active in recreational sports participated, mean age 24.0 ± 1.6 years; MAIN OUTCOME MEASURES: Correlations (Pearson's r), reliability (Intraclass Correlation Coefficient), Standard error of the measurement, Minimal detectable change., Results: Correlations to isokinetic assessments at 60° & 180°/second were moderate to strong for isometric (r: 0.68-0.80) and functional testing (r: 0.55-0.83) and weak for repetition to failure testing (r: 0.37-0.74). All isokinetic (ICC: 0.88-0.94), isometric (ICC: 0.83-0.94), and functional assessments (ICC: 0.80-0.92) had good to excellent intra-rater reliability, while repetition to failure testing had poor to moderate reliability (ICC: 0.48-0.57). The inter-rater reliability of the isometric assessments was moderate to excellent (ICC: 0.71-0.92) across movements. Expressed as a percentage of the mean, the standard error of the measurement ranged from 7% to 25% and the minimal detectable change ranged from 20% to 69% across all assessment methods., Conclusion: The isokinetic, isometric, and functional assessments used in this return to sports testing battery demonstrates acceptable validity and reliability. Further refinement to the methods used to assess muscular endurance is needed to improve reliability. This study offers clinicians information that can be utilized in clinical decision-making as it relates the testing battery's psychometric properties., Competing Interests: Declaration of competing interest None declared., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: The objective was to establish normative data for hip strength, flexibility, and stiffness in male soccer athletes and to investigate the effect of age and limb dominance on these variables., Design: Cross-sectional., Setting: Soccer team physical therapy department., Participants: A total of 293 asymptomatic male soccer athletes were assessed. Elite youth players aged 15-17 years and professional adult players aged 18-29 years old., Main Outcome Measures: Rectus femoris, iliopsoas, hamstring muscle flexibility, passive hip stiffness, and isometric hip strength were measured using a goniometer, inclinometer, and handheld dynamometer, respectively. Descriptive and mixed analyses of variance were used as statistical procedures., Results: The dominant limb had lower iliopsoas (P = 0.010) and rectus femoris (P = 0.003) flexibility and higher external rotators torque compared to the non-dominant limb (P = 0.006) in both age groups. In adult athletes, the dominant limb had lower hip stiffness than the non-dominant limb (P = 0.002). Adults had higher hip external rotator torque than younger athletes (P < 0.0001). No differences were observed for hamstrings flexibility and hip extensors torque., Conclusion: This study provided normative data of hip strength, flexibility, and stiffness for youth and adult male soccer athletes. In addition, there were no clinically relevant inter-limb differences., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: To investigate the relationship between one eccentric and two isometric tests commonly used to assess hamstring strength in professional soccer., Settings: Professional soccer club., Design: Cross-sectional study., Participants: Twenty male professional soccer players., Main Outcome Measures: Hamstring force was quantified during 3 tests (Nordic hamstring eccentric, 90:20 isometric posterior-chain strength and isometric 15° knee flexion) using a load cell, a handheld dynamometer and a force platform, respectively., Results: Poor relationships and low concordance were observed between isometric and eccentric tests, showing different ability to discriminate hamstring weakness and asymmetries. The Nordic hamstring test identified between-limb asymmetry >15% in 30% of the players, 25% in the 15° knee flexion and 5% in the 90:20 test. All players obtained different results in the three tests with only one showing asymmetry >15% in two tests., Conclusion: Results obtained in each test cannot inform the others. Mechanical outputs of these tests must be used for particular purposes during the prevention, rehabilitation and monitoring process of hamstring injury. Isometric testing might be preferable during the initial phases of the recovery process of a hamstring injury while the Nordic hamstring test might be used in the last stages or detect muscle weakness/asymmetries in non-injured players., Competing Interests: Declaration of competing interest None declared., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study was to examine the relationships between isometric handgrip (HG) strength and isokinetic strength data of the glenohumeral rotator muscles. Twelve (Female = 50%) Brazilian Sitting Volleyball (SV) national team players volunteered. Measures of maximal grip strength were obtained by a HG dynamometer Jamar® and isokinetic measures of peak torque (PT) and total work (TW) during shoulder rotations movements were obtained with a Biodex isokinetic dynamometer at speed of 60°/s and 180°/s. Pearson correlation coefficients between isometric HG and isokinetic strength data ranged between 0.23 and 0.72 for the PT and between 0.3 and 0.76 for the isokinetic TW. Results presented positive relationships between HG isometric strength and isokinetic strength of external rotators of the shoulder in SV players. We can suggest that in the absence of isokinetic dynamometers, HG isometric strength measurements could be used to measure strength levels of the external rotator muscles of elite SV players' shoulder, particularly in the TW values., Competing Interests: Declaration of competing interest The authors have no conflict of interest to declare., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: To systematically review the literature analyzing the reliability and characteristics of the protocols of isokinetic and isometric evaluation of the trunk flexor and extensor muscles with isokinetic dynamometer., Methods: This is a systematic review using PubMed, CENTRAL, LILACS, PEDro and SCOPUS databases, searching the oldest records up to December 2019. The risk of bias, the methodological quality and the level of evidence were evaluated using the COSMIN checklist., Results: Fourteen articles have met the criteria and have been included in this study. All the articles performed an isometric or isokinetic evaluation of the trunk muscles with the isokinetic dynamometer and presented an analysis of the protocol's reliability using the intraclass correlation coefficient. Five articles had excellent reliability (0.93-0.98). Most of the studies presented doubtful and inconsistent psychometric values for reliability, because they used a short period between tests. The level of evidence to the fourteen selected articles for reliability was moderate., Conclusions: Although the studies present limitations in methodological quality, it was possible to identify highly reliable patterns in the parameters employed and to present recommendations for the assessment of trunk flexor and extensor muscles in the isokinetic dynamometer, both for assessment in the sitting position and orthostatic., Competing Interests: Declaration of competing interest The authors state that there are no conflicts of interest regarding the publication of this review., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: To investigate the validity and intrarater and interrater reliability of eccentric strength testing of the shoulder abductors using a hand-held dynamometer (HHD) versus an isokinetic dynamometer., Design: Methodological., Setting: Research laboratory and athletic training room., Participants: Forty-seven asymptomatic shoulders of 25 participants were tested in 2 sessions by 2 physiotherapists., Main Outcome Measures: Eccentric strength of the shoulder abductors was measured from 120° to 30° scapular plane abduction using the HHD and isokinetic dynamometer. A gyroscope was used to validate the velocity. Spearman's rank correlation coefficients, intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated., Results: The measurement protocol showed excellent intrarater (ICC[3,3] = 0.987, SEM = 2.59 Nm and MDC = 7.18 Nm) and interrater (ICC[3,3] = 0.990, SEM = 2.28 Nm and MDC = 6.32 Nm) reliability. HHD and isokinetic dynamometer measurements were strongly correlated (rho = 0.760, p < .001). Velocities during HDD testing were similar to those of the isokinetic dynamometer (30°/s) (p > .050)., Conclusions: Eccentric strength testing of the shoulder abductors using an HHD is a valid and reliable method that can be used for research and clinical purposes when an isokinetic dynamometer cannot be used., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: To compare ankle, knee and hip isometric peak torque between young and middle-aged adults with CAI, copers and un-injured controls., Design: Cross-sectional., Setting: Research Laboratory., Participants: One hundred fifty-six young and middle-aged adults with or without CAI volunteered., Main Outcome Measures: A handheld dynamometer measured isometric dorsiflexion, plantarflexion, knee extension, hip extension and hip abduction peak force during a 5 s trial. Average peak torque was calculated and normalized to body mass., Results: A significant Age by Injury interaction for dorsiflexion suggest middle-aged un-injured controls (p < 0.001) and copers (p < 0.001) had lower isometric peak torque compared to their young adult counterparts, but there were no differences between young and middle-aged adults with CAI (p > 0.05). Significant Injury main effects suggest the CAI group had decreased plantarflexion (p = 0.004) and hip extension (p = 0.010) strength compared to un-injured controls, but not copers (p > 0.05). Significant Age main effects for all primary outcome measures were observed, indicating peak torque decreased with age (p < 0.05)., Conclusions: Regardless of age, isometric ankle and hip peak torque was lower in participants with CAI compared to un-injured controls, but not copers. These findings provide further evidence towards the impact of CAI in both young and middle-aged adults., Competing Interests: Declaration of competing interest None declared., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: Different angles and positions may influence the reliability and validity of hip strength dynamometry. This study examined the reliability and validity of hip strength measured with belt-stabilized handheld dynamometry (HHD) compared to isokinetic dynamometry (IKD) across multiple angles., Design: Repeated measures., Setting: Biomechanics laboratory., Participants: Thirty healthy participants completed 3 sessions., Main Outcome Measures: Hip torque was measured for hip abduction (ABD; -10°, 0°, 20°, and 40°), internal rotation (IR; -30°, -15°, 0°, 15°, and 30°), external rotation (ER; -30°, -15°, 0°, 15°, and 30°), and extension (EXT; -10°, 0°, 30°, 60°, 90°, and 120°)., Results: ABD was reliable (no intratester reliability differences p = 0.409-0.997; ICC = 0.624-0.900) and valid (no HHD-IKD difference p = 0.270-0.946; r = 0.556-0.624) measure. IR had questionable reliability (intratester reliability differences p = 0.001-0.043; ICC = 0.682-0.879) and validity (HHD-IKD differences p < 0.001; r = 0.393-0.771). ER was reliable (no intratester reliability differences p = 0.226-0.937; ICC = 0.731-0.876) but not valid (HHD-IKD differences p < 0.001-0.003; r = 0.194-0.651). EXT showed varying levels of reliability and validity; 30° was both reliable and valid. Peak torque occurred in a lengthened position for ABD, ER, and IR, and at 90° of hip flexion for EXT., Conclusions: HHD can be an effective tool for measuring strength under certain circumstances; however, IR/ER testing should be used with caution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Hand grip strength has been widely used as a lead measure in geriatric conditions such as frailty. However, diversity in assessment protocols and methodologies creates uncertainty in the comparison of outcome measurements. The aim of this study was to review the literature relating to the measurement of hand grip strength in older adults, in order to develop further consensus in relation to the use of existing protocols in clinical and community settings, with an emphasis on practicality and suitability for frail persons., Methods: Five electronic English databases were searched using keywords such as 'hand grip strength', 'clinimetric assessment', and their synonyms. Age-related trends in adults aged ≥65 years were assessed, and comparisons were made of the following variables: dynamometer model and handle setting, hand positioning, warm-up trials, grip duration, number of repeated tests, rest periods, laterality of tested hand, and whether encouragement was given to the subjects., Results: Thirty-four research papers met the inclusion criteria and were included. A Jamar hand dynamometer was most frequently used. Variations were found in the positioning of the subject and in the duration of the rest period, which ranged from 10 to 20 s to 1 min. Grip strength was typically measured three times in the dominant hand, with the strongest grip being recorded and no encouragement being provided during assessment., Conclusions: Based on the scoping review, we propose a detailed and standardised protocol that is suitable for the assessment of hand grip strength in frail older adults., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

1st MTP arthrodesis often alleviates pain in osteoarthritis of hallux, long term outcomes vary, yet there is little known about potentially modifiable changes in the small muscles of the foot and hallux. This study was performed to determine the changes in the size of the Intrinsic Foot Muscles (IFMs) after the arthrodesis of the 1st metatarsophalangeal (MTP) joint by comparing the cross-sectional area (CSA) and muscle thickness (MT) of Abductor Hallucis (AbH), Flexor Digitorum Brevis (FDB) and Flexor Hallucis Brevis (FHB) between surgical and non-surgical feet. A convenience sample of 18 feet of 9 subjects (age: 57.56±9.07, weight: 81.33±1.32kg, height: 163.26±11.03cm) with a unilateral history of 1st MTP arthrodesis was recruited. B-mode ultrasound images were collected during sitting and standing positions with a wireless 8-MHz transducer. Hand-held dynamometer was used to measure toe flexion strength. CSA and MT of the surgical feet were significantly lower (P<0.05) for AbH and FHB in both positions. For FDB, the significant difference (P<0.05) was smaller MT in standing. Significantly lower (P<0.05) toe strength was observed in involved toe compared to uninvolved. Greater correlations were seen between toe strength and CSA of FHB and AbH in uninvolved toes compared with involved toes. IFMs in the surgical foot exhibited reduced CSA and MT. Weak core muscles of the foot may result in transmission of shock and forces to the foot skeleton which can lead to skeletal problems such as metatarsalgia, IP joint arthritis etc. that are seen as post-surgical complications. There is nothing in literature that delineates the rehabilitation of foot in this group of patients after surgery. This directs surgeons and clinicians to integrate IFM training in the rehabilitation programs after surgery. Developing appropriate rehabilitation protocols for these patients may help in preventions of post-surgical complications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: To investigate the concurrent validity of the Modified Sphygmomanometer Test (MST) with fixed stabilization, compared to the portable dynamometer, and to verify its test-retest and inter-raterreliability., Methods: Methodological study. The muscle strength of the following groups was measured: flexors and extensors of the wrist, of the hip, and of the knee and plantar flexors. The Tycos® aneroid sphygmomanometer and the Microfet 2® dynamometer were used. Stabilization was performed using the Mullingan® belt. Descriptive statistics were performed for characterization of the sample. To determine the validity of the MST with fixed stabilization, comparing it with the portable dynamometer, we investigated the correlation between the measurements obtained with the two instruments using the Pearson correlation coefficient. Intraclass Correlation Coefficient (ICC) was used to investigate inter-examiner and test-retest reliability (α = 0.05)., Results: 59 individuals were included (1176 evaluations). A statistically significant correlation of moderate to high magnitude (0.58 ≤ r ≤ 0.81) was observed for concurrent validity of the MST with fixed stabilization versus the portable dynamometer for all muscle groups. Regarding inter-rater reliability, it was observed statistically significant ICC considered excellent to good (0.72 ≤ r ≤ 0.94) for all muscle groups. Regarding test-retest reliability, first evaluator presented good to excellent ICC (0.64 ≤ r ≤ 0.94), while second evaluator presented good to excellent ICC (0.74 ≤ r ≤ 0.96) for all muscle groups., Conclusion: The MST with fixed stabilization is valid and reliable for clinical measurement of muscle strength and can overcome previous limitations reported in the literature., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: Chronic pain is a debilitating condition that affects many people. Currently, there is no single treatment known to cure or assure relief from chronic pain. Accordingly, the management of patients' discomfort is an integral part of treating chronic pain. Such treatment, however, is not effective for many patients. We investigated whether mirthful laughter provided by comic relief can influence pain tolerance and muscle soreness in young healthy participants., Methods: Forty participants underwent a randomized controlled cross-over designed experiment. Each participant was exposed to a comedy video eliciting mirthful laughter and an uninteresting documentary. Delayed onset muscle soreness was induced in one leg at a time by eccentric exercise. Pain tolerance was tested using blunt force application and assessed subjectively using a visual analog scale., Results: Watching the comedy video elicited a significantly greater irregular breathing pattern compared with watching the documentary video (p < 0.001). After watching the comedy, the participants' positive affect was increased (Δ2 ± 1) while it was largely decreased (Δ-11 ± 2) after watching the documentary video (p < 0.001). Pain tolerance was decreased by 17 ± 5 N after viewing the documentary video (p < 0.001), but did not change significantly after watching the comedy., Conclusions: Thirty minutes of watching a comedy eliciting laughter favorably influenced pain tolerance in healthy humans. CLINICAL TRIAL NO.: #NCT02896075., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: This study compared the effects of 90 s of manual compressive therapy (MCT) on latent myofascial trigger points (LTPs) for 3 sessions per week for 4 weeks to determine changes in individual pressure pain threshold (PPT). A total of 30 (15 males, 15 females; age = 22 ± 4 y/o, height = 175 ± 18 cm, weight = 162.5 ± 57.5 kg) symptomatic subjects with LTPs volunteered for the study., Methods: PPT was measured at baseline and pre- and post-treatment for all 12 sessions with a pressure algometer across the 4-week treatment time frame. The MCT was applied to the control group on their LTP at pressure intended to provide a sham condition (1/10 on verbalized analog scale (VAS)). Two experimental groups had MCT applied either directly on the LTP (d-TP) or in close-proximity to their LTP (cp-TP) at moderate pressure (7/10 on VAS)., Results: There was a significant increase in PPT from the first through twelfth treatment sessions (p < 0.001, partial η 2  = 0.914). A significant increase in PPTs between treatment groups was acutely observed from pre- to post-therapy tests (p = 0.001, partial η 2  = 0.146). The differences between pre- versus post-treatment PPT measures indicated significant differences (d-TP vs. control, p < 0.001; cp-TP vs. control, p = 0.007). No differences were observed between experimental groups (p = 0.215)., Conclusions: PPT continued to increase after several weeks of MCT when applied directly on or within 2.5 cm of an identified LTP compared to control., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Producing the target force of a muscle group by using visual feedback and reproducing the same force fully blind are regarded as a common approach for quantifying the sense of force. Force sense error is considered to be the difference between the produced target force and reproduced force. The present study aimed to evaluate the effects of tactile sensory feedback in the lower leg on the perceived magnitude of force sense., Methods and Materials: In this cross-sectional study, 18 healthy men (mean age 24.31 ± 3.94 years) were selected based on a simple randomized method. First, the quantity of force sense error of the knee extensor muscle group was measured before and after manipulating the tactile inputs of the leg. Then, methods A, B, and C were applied to measure force sense errors. In addition, the tactile impulses were manipulated in methods B and C by placing a piece of thick foam between the distal portion of lower leg among the subjects and the dynamometer. The tactile inputs remained intact during method A., Results: The accuracy of the reproduced target force was significantly affected following the disturbance of tactile inputs in the lower leg in methods B and C, compared to method A (p < 0.05)., Conclusion: Altering tactile inputs in the lower leg can affect the force sense of the knee extensor muscles. The received somatosensory inputs across the lower leg can affect the whole process of force perception at this joint., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: To assess glenohumeral joint (GHJ) rotation strength across a rugby league season, since strength of rotator cuff musculature may protect against contact injuries to the shoulder., Design: A prospective cohort study was used to compare GHJ rotation pre-, in-, and post-season., Setting: Laboratory., Participants: Twenty-nine players from a professional European Super League club., Main Outcome Measures: Isokinetic dynamometry for concentric and eccentric muscle actions for shoulder internal and external rotation at 240°/s. Peak torque, traditional strength ratios, and dynamic control ratios were compared., Results: There were no significant differences between peak torque strength parameters at any time point. Similarly, differences in strength ratios failed to reach statistical significance across the season. Ipsilateral strength ratios were indicative of selective strengthening of internal rotators for concentric and eccentric muscle actions., Conclusions: The findings suggest that rugby league players are no more likely to sustain a shoulder injury in the latter stages of the season as a result of decreased GHJ rotation strength. Players were able to maintain strength across the season which is valuable to practitioners developing conditioning programmes to optimise performance and minimise the risk of injury. This may afford protection, particularly during forced external rotation following physical contact., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: To verify the intrasession reliability and the agreement between strength measurement of hip and knee muscles using hand-held dynamometer stabilized by a belt or by an examiner., Design: Test-retest design., Setting: Knee and hip muscles strength were measured bilaterally using hand-held dynamometer stabilized by a belt and by an examiner., Participants: 24 young and healthy participants., Main Outcome Measures: The reliability was verified by the intraclass correlation coefficient 2,1 and the standard error of measurement. Agreement between stabilization methods was verified by the Bland Altman's method., Results: Reliability was excellent for all muscle groups when stabilized by a belt (intraclass correlation coefficient = 0.78 to 0.95) and by the examiner (intraclass correlation coefficient = 0.83 to 0.97); standard error of measurement ranged between 1kgf to 4kgf at both methods, but they are proportionally lower when stabilized by the examiner. No agreement between both methods was identified for all knee strength measurements and for bilateral hip flexion, right internal and external rotation and left adduction., Conclusions: The hand-held dynamometer is reliable for hip and knee strength evaluation despite of the stabilization method. However, for the majority of the movements, greater strength and lower error are expected when the examiner stabilizes it., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: to assess intra/inter-operator reliability and agreement of maximum isometric abdominal and back muscle strength in a functional trunk and isolated lumbar protocol, using an isokinetic dynamometer, in healthy persons and persons with chronic nonspecific low back pain (CNSLBP)., Design: Test-retest., Setting: Participants performed two assessments consisting of two protocols on the Biodex 3 system, evaluating maximum isometric back and abdominal strength in a functional trunk and isolated lumbar position. During the first assessment, each protocol was executed twice, supported by different operators., Participants: Healthy persons (n = 20) and persons with CNSLBP (n = 20)., Main Outcome Measures: Intraclass Correlation (ICC), Standard Error of Measurement (SEM and %SEM), and Minimal Detectable Change (MDC) of muscle strength outcomes and seat positioning characteristics were calculated., Results: Intra/inter reliability of muscle strength outcomes was excellent (ICC: 0.94-0.98), while seat positioning characteristics varied from low to high (ICC: 0-0.94). For muscle strength outcomes, %SEM ranged from 4.7 to 9.2% and MDC ranged from 14.3 to 29.8 Nm in trunk flexion and 39.1-68.5 Nm in trunk extension., Conclusions: The Biodex 3 system can be used reliably to assess maximum isometric trunk muscle strength with the aforementioned protocols in healthy persons and persons with CNSLBP. All muscle strength outcomes showed comparable agreement (%SEM < 10%)., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: Determine how the strength and endurance of the plantar flexors are affected by Achilles tendinopathy and whether one muscle is more affected than another., Design: Case control study., Setting: University Laboratory., Participants: 39 Runners with mid-portion Achilles tendinopathy and 38 healthy runners participated in this study., Main Outcome Measures: Isokinetic dynamometry was completed bilaterally in two knee positions on all subjects to assess the torque and endurance capacity of the plantar flexors., Results: Subjects with Achilles tendinopathy were statistically weaker (by 26.1Nm Concentric 90°/sec, 14,8Nm Concentric 225°/sec and 55.5Nm Eccentric 90°/sec for knee extended testing and 17.3Nm, 10.1Nm and 52.3Nm for the flexed knee respectively) than healthy controls at all isokinetic test speeds and contraction modes irrespective of knee position (p value = <0.001). The endurance capacity of the plantar flexors was significantly reduced (Total work done 613.5Nm less) in subjects with Achilles tendinopathy when compared to the healthy controls (p value = <0.001)., Conclusions: Achilles tendinopathy is associated with large deficits in plantar flexor torque and endurance. The deficits are bilateral in nature and appear to be explained by a greater loss of the soleus force generating capacity rather than the gastrocnemius., (Copyright © 2019. Published by Elsevier Ltd.)

Objective: To investigate test-retest reliability of a hip strength assessment system (GroinBar)., Design: Test-retest reliability study., Setting: Laboratory., Participants: Twenty asymptomatic varsity soccer players., Main Outcome Measures: Maximal isometric hip strength (adduction, abduction, internal and external rotation, flexion and extension) was assessed using the GroinBar. Intraclass correlation coefficient (ICC) and relative standard error of measurement (SEM) were calculated to evaluate reliability of peak (ICC 3,1 ) (highest peak within 3 trials) and average peak (ICC 3,3 ) (average of 3 trials) force and rate of force development (RFD). Hotelling's T 2 , were also used to compare bilateral and reciprocal ratios between dominant and non-dominant leg., Results: ICC for both peak force and RFD values revealed moderate to good reliability (0.53-0.88 and 0.61-0.84, respectively), whereas reliability was good to excellent regarding their average values (0.77-0.95 and 0.81-0.92, respectively). SEM of average peak force and RFD values (4.1-9.4% and 8.2-13.9%, respectively) were lower than that of peak force and RFD values (5.7-13.0% and 10.7-19.1%, respectively). No significant difference was found in bilateral and reciprocal force ratios between dominant and non-dominant leg., Conclusions: The GroinBar is a reliable tool to assess hip muscle function in athletic populations and could be used for player screening and follow-up., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: To evaluate differences in clinical measures of hip abductor and extensor capacity (strength, endurance and power) in people with patellofemoral pain (PFP) compared to asymptomatic controls., Design: Cross-sectional., Settings: Laboratory., Participants: Thirty-two physically active people (16 with PFP and 16 controls)., Main Outcome Measures: Strength was evaluated isometrically using a hand-held dynamometer and dynamically using 10 repetitions maximum (10RM) tests. Power was assessed using a linear position transducer. Endurance was assessed using maximum number of repetitions., Results: The PFP group had significant deficits compared to the control group in isometric strength (21-25%) for hip abduction (ES = 0.98) and extension (ES = 0.85); in 10RM (15-18%) for hip abduction (ES = 0.72) and extension (ES = 0.85); and in power (24-31%) for hip abduction (ES = 0.80), and extension (ES = 0.94). No difference was identified for hip abduction and extension in endurance tests., Conclusion: Clinical assessments can identify deficits in isometric and dynamic hip strength, as well as power in people with PFP. Hip muscle capacity deficits in people with PFP including strength and power highlight a potential need for more progressive resistance training in this population., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: To identify whether baseline differences in hip and knee isometric strength exist among female runners who sustained a running related injury (RRI) and those that remained injury-free during a 16-week formalized training program., Design: Prospective Cohort., Setting: Laboratory Setting., Participants: 54 healthy female recreational runners enrolled in a formalized training program for half or full marathon. At the conclusion of the program, 50 female runners (age: 39.1 ± 9.4 years; height: 165.3 ± 7.4 cm; mass: 64.8 ± 11.9 kg) were included in analysis., Main Outcome Measures: Peak isometric torque of knee flexion and extension, hip flexion and extension, and hip abduction and external rotation were compared between runners who sustained an RRI and injury-free (INJF) runners., Results: 15 of the 50 participants developed an RRI during the observational period, no between groups differences existed for any demographic variable. Hip and knee isometric strength was not different prior to the start of a 16-week formalized training program between runners who sustained an RRI and those that remained injury-free., Conclusions: Hip and knee weakness does not appear to be a baseline characteristic among female recreational runners who sustained an RRI or remained uninjured while training for a half or full marathon., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Quadratus plantae (QP), one of the plantar intrinsic foot muscles, assist plantarflexion of the lesser toes. QP has medial and lateral muscle heads with different anatomical structures. The two heads of this muscle may have different roles in foot function. Ultrasound real-time tissue elastography (RTE) measurements have allowed quantitative assessment of deep-layer muscle elasticity. The purpose of this study was to determine the activity of the QP in flexion movements of the lateral four toes using RTE. Thirteen healthy subjects performed maximal voluntary contractions using a hand-held dynamometer with external belt fixation for each toe flexion movement. The elasticity of the muscles were measured using RTE during rest and flexion of each toe. The strain ratio of the muscle to that in an acoustic coupler was calculated as an index of muscle elasticity. Higher strain ratio values imply lower elasticity. The strain ratio of the medial head of QP for second toe flexion (0.10±0.11) was significantly stiffer than at rest (0.34±0.33). The strain ratios of the lateral head of QP for flexion of the second (0.32±0.19), third (0.41±0.37), fourth (0.33±0.26), and fifth (0.45±0.39) toes were significantly stiffer than at rest (1.02±0.68). These results suggest that the medial head of QP has a role in assisting second-toe flexion, and the lateral head has a role in assisting flexion of all four lateral toes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: To investigate the intra- and interrater reliability and agreement for field-based assessment of scapular control, shoulder range of motion (ROM), and shoulder isometric strength in elite youth athletes., Design: Test-retest reliability and agreement study., Setting: Eight blinded raters (two for each assessment) assessed players on field during two testing sessions separated by one week., Participants: 162 elite youth handball players with or without a history of previous shoulder pain within the preceding six months., Main Outcome Measures: Kappa (κ) and prevalence-adjusted bias-adjusted kappa (PABAK) coefficients for scapular control reliability, and 95% limits of agreement (LOA) for ROM and strength agreement., Results: Scapular control demonstrated substantial to almost perfect reliability (κ 0.67 to 0.84, PABAK from 0.68 to 0.88). Mean strength values ranged from 0.9 N/kg to 1.6 N/kg, and LOAs ranged from -0.7 N/kg to 0.8 N/kg. Rotational strength revealed additionally systematic bias between and within rater. No or acceptable systematic bias were evident for ROM and abduction strength measures. Mean values and LOAs for ROM ranged between 39.9° to 52.3°, and from -12.6° to 9.9°, respectively., Conclusions: Scapular control and ROM can be assessed on the field with acceptable reliability. The threshold for reliable measurements of isometric strength using handheld-dynamometers is high., (Copyright © 2018. Published by Elsevier Ltd.)

Objective: The aim of the study was to compare the dimensions of cervical multifidus muscle (CMM) in different conditions., Methods: Twenty five women with neck pain and 25 healthy subjects participated in this study. The dimensions of the CMM were measured at rest, 50% and 100% maximum isometric voluntary contraction (MIVC) at six directions of neck movements, using ultrasonography., Results: The size of multifidus was smaller in patients than healthy individuals at rest state (P < 0.05). A significant smaller CMM dimension was found in the affected side compared with unaffected side in patients group (P < 0.05). The result of ANOVA for MLD showed a significant difference for contraction levels (P < 0.001) and neck movements (P < 0.001) in both groups. The MLD of the CMM was significantly different between CMM at rest and 50%, and 100% MIVC (P < 0.001). No significant differences were found between the groups at 50% and 100% MIVC (P > 0.05 in both instances). The most prominent CMM size change was observed during neck extension, flexion, ipsilateral lateral-flexion, and ipsilateral rotation, respectively (P < 0.05)., Conclusions: Results of the present study indicate that the size of CMM was decreased in patients with neck pain in rest state. The size of CMM changes in all directions of neck movements, although the most prominent was during neck extension. This points out CMM stabilization role's in different directions of neck movements., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The purpose of this study was to clarify the relationship between the size of the cervical flexor muscles and craniocervical (CC) flexion torque. Thirty-eight healthy men participated in this study. Thickness of the deep cervical flexor (DCF) and sternocleidomastoid (SM) muscles were measured using ultrasonography. Maximal isometric CC flexion torque was measured using dynamometry. The DCF and SM muscle thickness and CC flexion torque were normalized relative to body weight. Correlations between normalized muscle thickness and normalized CC flexion torque were determined. A significant positive correlation was observed between normalized DCF muscle thickness and normalized CC flexion torque (r = 0.361, P = 0.028), whereas there was no significant correlation between normalized SM muscle thickness and normalized CC flexion torque (r = 0.233, P = 0.166). DCF muscle thickness appears to have potential clinical application in the performance of CC flexion., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To investigate the immediate effect of electrical stimulation of the common peroneal nerve on the maximum voluntary activation of the quadriceps muscle in patients with knee osteoarthritis., Methodology: Fifteen subjects with knee osteoarthritis (mean age: 50.5 ± 13 years) participated in this study. To measure the arthrogenic inhibition ratio of quadriceps, a burst of electrical stimulation was superimposed on the maximum voluntary contraction, and the percentage of change in the force production was computed. The same measurement was also performed with concurrent electrical stimulation of the common peroneal nerve., Results: All the patients with knee osteoarthritis showed significant arthrogenic inhibition of the quadriceps muscle. The stimulation of the common peroneal nerve was able to reduce this inhibition and increase the capacity of the muscle to produce a significantly higher knee extension force (p = 0.028)., Conclusions: Electrical stimulation of the common peroneal nerve concurrent with the maximum voluntary effort can remove the arthrogenic inhibition of the quadriceps muscle in patients with knee osteoarthritis. This finding could have clinical implications in the management of patients with knee disorders., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To estimate the prevalence of low handgrip strength (HGS) levels and sociodemographic characteristics, health behaviours and body fatness status related in adolescents., Method: Cross-sectional epidemiological study with 636 adolescents aged 14-19 years in a city in southern Brazil. HGS was measured by dynamometer. Sociodemographic and behavioural data were collected using self-report questionnaires. Body mass and height was measured by Body Mass Index., Results: Prevalence of low HGS levels was 47% (63.5% boys, 37.7% girls). Boys aged 14-16 years were more likely to have low HGS levels. Girls who were of higher socioeconomic status and who were less physically active were more likely to have low HGS levels. Overweight girls were less likely to have low HGS levels., Conclusions: High prevalence of low HGS levels was observed in adolescents. Increased HGS levels should be focused on younger boys and normal-weight girls with higher socioeconomic status and lower levels of physical activity., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To compare the knee performance and pain in athletes with patellofemoral pain syndrome (PFPS) before and after applying Kinesio Tape ® (KT) on vastus medialis obliquus (VMO) muscle., Participants: Fifteen participants (10 females, five males) with unilateral PFPS were examined and compared under taped and untaped conditions., Intervention: VMO of the involved leg was taped from origin to insertion, with 75% of KT's maximal length tension., Main Outcome Measures: Maximal eccentric and concentric peak torques of quadriceps were measured at 60 and 180°/s angular velocities by an isokinetic dynamometer. Functional performance and pain were evaluated by functional tests (step-down and bilateral squat) and visual analog scale, respectively., Results: Paired t-test showed statistically significant increase in VMO peak torque and also repetition of step-down test and bilateral squat after using KT. Pain intensity was also decreased significantly following KT application (p < 0.05)., Conclusions: KT application over VMO can decrease pain and improve the functional performance, generally and quadriceps muscle strength, particularly, in athletes with PFPS. However, more research is needed to evaluate the long-term effects of this therapeutic procedure., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: Pilates has been shown to be effective for increasing muscle strength in older adults, however, some variables have not yet been explored., Objective: Investigate the effects of Pilates on the isokinetic muscular strength of the knee extensors and flexors at 60°/s, in elderly women., Method: Thirty-two women were randomized into two groups: control group (CG, n = 16, age = 64.2 ± 0.8 years; BMI = 25.0 ± 1.2 kg/m 2 ), and experimental group (EG, n = 16, age = 63.6 ± 1.0 years, BMI = 24.7 ± 1.3 kg/m 2 ). Isokinetic evaluation of the knee extensor and flexor muscles was performed at 60°/s, pre- and post-intervention, considering the peak torque (N.m) and total work (J) for the right and left lower limbs. The CG participated in static stretching and the EG in Pilates sessions, twice a week for 12 weeks., Results: The results demonstrated that the EG presented a significant improvement (p < 0.01) in all tests performed, when comparing the pre- and post-intervention (intragroup), with an effect size (Cohen's d) reaching 2.03 and 1.33 for the knee flexor and extensor muscles respectively. Comparing the CG and EG (intergroup), post-intervention, a significant improvement was observed (p ≤ 0.01) in favor of the EG for all variables, with an effect size (Cohen's d) reaching 1.59 and 1.15 for the knee flexor and extensor muscles respectively., Conclusion: The results indicated that 12 weeks of Pilates increases the isokinetic muscular strength of the knee extensors and flexors in elderly women and can be considered for this purpose when prescribing physical exercise programs., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the rate of force development (RFD) and the rate of electromyography rise (RER) of global and local trunk muscles in women with and without low back pain., Design: Cross-sectional study., Setting: Laboratory setting., Participants: Twenty-eight women divided into low back pain (LBP, n = 14) and control groups (CG, n = 14) participated in this study., Main Outcome Measures: Subjects performed isometric contractions of trunk using an isokinetic dynamometer, and simultaneously the electromyography (EMG) signals were collected for global (rectus abdominis and longissimus thoracic) and local (internal oblique and multifidus) muscles. All variables were calculated using Matlab software., Results: Symptomatic subjects showed lower RFD during trunk extension and it was correlated to a reduced RER mainly in the trunk extensor musculature (p < 0.05). During trunk flexion, LBP exhibited a delayed time to reach peak RFD (p < 0.05) compared to CG. RER for global anterior muscle was higher than for local muscle (p < 0.05) and it was more persistent in asymptomatic women. CG also presented greater activation amplitude for both agonist and antagonist trunk muscles, mainly the global ones., Conclusion: Symptomatic women showed lower RFD and it was correlated to a reduced capacity of rapid muscle activation mainly in the trunk extensor musculature., (Copyright © 2017 Elsevier Ltd. All rights reserved.)