Isokinetic Assessment Research Articles

Feasibility And Responsiveness Of Isokinetic Quadriceps Function In Patients With Chronic Obstructive Pulmonary Disease

Peripheral muscle dysfunction has been associated with impaired health status and increased mortality in patients with chronic obstructive pulmonary disease (COPD). This highlights the importance of assessing and targeting peripheral muscle strength and endurance during pulmonary rehabilitation (PR). However, information regarding the feasibility and responsiveness of isokinetic quadriceps function following PR is limited. PURPOSE: To evaluate whether and to what extent the isokinetic evaluation of quadriceps muscle function meets the pre-defined test criteria in COPD patients; to determine the response to PR of isokinetic quadriceps muscle function. METHODS: A retrospective analysis of 2033 COPD patients (age: 65 ± 9 years, 52% male, forced expiratory volume in 1st second: 49 ± 22% predicted) following PR was performed. Individualized exercise training consisted of endurance, interval and strength straining and/or neuromuscular electrical stimulation. Isokinetic quadriceps function assessment consisted of 30 maximal extension-flexion contractions with a full range of motion at a fixed angular speed of 90°/s (computerized dynamometer). Criteria for a correct test performance were: completion of all 30 repetitions, peak torque reached within first five repetitions, and presence of work fatigue. Differences between pre and post PR were tested using paired t-tests. RESULTS: Pre PR, 27% of the patients did not fulfil one or more of the predefined test-criteria. In patients with a correct pre and post PR isokinetic test (n = 989), isokinetic quadriceps peak torque (∆ = 8 ± 12 Nm) and total work (∆ = 229 ± 234 J) were responsive to PR (both p-values<0.001). There was no change in work fatigue index following PR. CONCLUSION: Based on the current test criteria, three in four patients with COPD performed the isokinetic quadriceps test correctly during a baseline PR assessment. PR has a beneficial effect on isokinetic quadriceps peak torque and total work, but not work fatigue index, in patients with COPD. Supported by Lung Foundation grant (#5.1.18.232).

Traditional and Additional Isokinetic Knee Strength Assessments of Athletes; Post-Operative Results of Hamstring Autograft ACL Reconstruction.

Background and Objectives: Anterior cruciate ligament (ACL) injuries are common injuries in athletes, and, accordingly, ACL reconstruction (ACLR) is one of the most common orthopedic surgical procedures performed on athletes. This study aims to compare the 6-month post-operative isokinetic knee strength evaluations of the semitendinous/gracilis (ST/G) ACLR technique performed on healthy (HK) and ACLR knees of athletes. Materials and Methods: A retrospective cohort of 29 athletes from various sports branches who underwent ST/G ACLR technique by the same surgeon were evaluated. The isokinetic knee extension (Ex) and flexion (Flx) strength of the patients on the HK and ACLR sides were evaluated with a series consisting of three different angular velocities (60, 180, and 240°/s). In addition to the traditional evaluations of peak torque (PT) and hamstring/quadriceps (H/Q) parameters, the findings were also evaluated with additional parameters such as the joint angle at peak torque (JAPT), time to peak torque (TPT), and reciprocal delay (RD). Results: There was a significant improvement in the mean Lysholm, Tegner, and IKDC scores after surgery compared with preoperative levels (p < 0.05). As for the isokinetic PT values, there were significant differences in favor of HK in the 60°/s Flx, 180°, and 240°/s Ex phases (p < 0.05). In addition, there was a significant difference in the 60° and 180°/s Flx phases in RD (p < 0.05). In H/Q ratio, TPT, and JAPT values, no significant difference was observed between HK and ACLR at all angular velocities. Conclusions: The findings showed that the ST/G 6-month post-operative isokinetic knee strength in athletes produced high results in HK, and, when evaluated in terms of returning to sports, the H/Q ratios on the ACLR side were sufficient to make the decision to return to sports. It was found that the ACLR side was slower than the HK side in the reciprocal transitions, particularly in the Flx phase. We believe that this results from the deformation of the hamstring muscle after reconstruction of the ST/G ACLR side.

Inter-limb asymmetries and kicking limb preference in English premier league soccer players.

The aims of this study were: (1) to quantify interlimb asymmetries in EPL soccer players in the context of kicking limb preference and (2) to establish the relationship between interlimb asymmetries and measures of physical performance. Twenty-two players (age: 21.8 ± 4.4 years) from an EPL club performed a running gait assessment (20 km/h) and unilateral countermovement jumps, a CoD assessment (modified 505 test), and an isokinetic knee extension/flexion protocol using each leg. Asymmetries were quantified using the percentage difference method and Pearson's correlations were used to quantify the association between variables. Players displayed the greatest level of asymmetry in isokinetic strength measures (5.9–12.7%) and lower levels of asymmetry in gait (1.6–7.7%), jump (0.9–7.0%) and CoD (1.9–3.5%) assessments. The influence of the preferred kicking limb was most evident in the isokinetic assessment with the players showing dominance in the preferred limb for knee flexor strength and in the non-preferred limb for knee extensor strength. These manifested in the asymmetry values calculated for the hamstring:quadricep (H:Q) ratios at 60°/s (8.80 ± 7.82%) and 240°/s (11.22 ± 7.04%) and in the functional H:Q ratio (12.67 ± 8.25%). The asymmetry values for peak extensor moment at 240°/s showed a significant correlation (ρ = −0.55, p = 0.034) with 10 m time in the CoD assessment. These findings provide benchmark asymmetry data for soccer practitioners and reveal that kicking limb preferences may bring about interlimb differences in the H:Q ratio which raises important considerations in the design of testing batteries and injury reduction interventions.

Use of hand hydraulic dynamometers as an overall evaluation of the upper-limb weakness in patients with thoracic outlet syndrome.

Patients with neurogenic thoracic outlet syndrome report pain and upper-limb weakness. They complain about weakness occurring on the entire upper-limb, especially at the hand and the shoulder levels. Hydraulic dynamometers can reliably assess the strength of the hand, and isokinetic shoulder testing can provide accurate and reliable evaluations of the rotators strength. Yet, isokinetic proximal assessment needs expensive tools, whereas hydraulic hand dynamometers are cheap and easy to use. We aimed to assess the correlation between the isokinetic shoulder strength and the hand grip and the key pinch strength. The grip strength was evaluated with a hydraulic hand dynamometer and the key pinch with a pinch gauge. Isokinetic rotators strength tests were performed using a Humac Norm® dynamometer at 60 and 180°/s. One-hundred and thirty patients had been included, 72% of women, mean age of 39.8 ± 9.5. Symptomatic hands presented a strength deficit of 12.2% on the grip (p < 0.0001) and 10% on the key pinch (p = 0.01). Isokinetic strength was lower on the symptomatic shoulders at 60 and 180°/s concerning medial rotators [−10.3 and −8.8%, respectively (p = 0.02)] and lateral rotators [−10.8 and −10%, respectively (p = 0.04 and p = 0.03)]. There was a moderate correlation between the grip strength of the symptomatic upper-limbs and the isokinetic rotators strength (p < 0.001). The key pinch strength was moderately correlated to the isokinetic medial and lateral rotators strength at 60°/s (p < 0.001). Hand dynamometers could prove useful during medical consultations or in outpatient management to assess upper-limb overall weakness, but isokinetic measurement remains the gold standard for a precise evaluation.

Relevant Strength Parameters to Allow Return to Running after Primary Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft.

After anterior cruciate ligament reconstruction (ACLR), a progressive process is followed from rehabilitation to the return to sport including a crucial step known as the return to running. Return to running (RTR) can be predicted by an isokinetic knee strength assessment at 4 months post-surgery. All patients who had primarily undergone ACLR with a hamstring autograft procedure between 2010 and 2020 were included in this study. Four months after surgery, patients were evaluated using an isokinetic knee strength test. Patients were monitored until the 6th month post-surgery to see if they had returned to running. Comparisons were carried out between the two groups—the RTR and the no-RTR. A multivariate logistic regression analysis was used to predict the RTR status from explicative parameters. Receiver Operating Characteristic (ROC) curves were established to identify cutoffs with their characteristics. A total of 413 patients were included and 63.2% returned to running at 4 months post-surgery. The mean Lysholm score, knee complication rate, and isokinetic parameters were statistically different between both groups. Using a multivariate logistic regression model and ROC curves, the best isokinetic parameter to assist with the decision to allow an RTR was the quadriceps limb symmetry index at 60°/s with a cutoff of 65%. The hamstring LSI at 180°/s could be added (cutoff of 80%) to slightly increase the prediction of an RTR. Quadriceps strength normalized to body weight at 60°/s is a useful parameter (cutoff: 1.60 Nm/kg) but measurements on both sides are necessary. Isokinetic parameters are objective parameters to allow a return to running at 4 months after ACLR with a hamstring procedure.

Persistent quadriceps muscle atrophy after anterior cruciate ligament reconstruction is associated with alterations in exercise-induced myokine production

PurposePersistent quadriceps muscle atrophy is observed in a subset of patients following anterior cruciate ligament reconstruction (ACLR) despite the completion of comprehensive rehabilitation. Critically, quadriceps muscle atrophy correlates with muscle weakness and quadriceps strength deficits. The aim of this study was to examine the effect of resistance exercise on myokine levels and muscle atrophy status in ACLR patients with persistent quadriceps muscle atrophy. MethodsSixteen participants between the ages of 18–39 with a Tegner score of >6 and who had undergone ACLR with hamstring graft were recruited for the study. Quadriceps muscle thicknesses were ascertained by ultrasonography and isokinetic strength assessments were made prior to commencing a single bout of resistance exercise training (RET). Blood samples were taken before and after RET and assayed for myokine expression. Self-reported activity level and knee function questionnaires were completed and recorded. ResultsClustering by quadriceps muscle size measurements created a non-atrophy group of 9 subjects and an atrophy group of 7 subjects. There were no significant between-group differences in anthropometric measurements, time post operation and knee function questionnaires, but the atrophic group comprised of patients with lower pre-injury sporting levels. The atrophy group exhibited significant lower side-to-side muscle thickness ratios and a decreasing trend in quadriceps strength deficits. Serum brain-derived neurotrophic factor (BDNF) was up-regulated in response to RET in non-atrophy group, but a negative fold change was detected in the atrophy group. ConclusionThe dysregulation in myokines plays an important role in patients failing to regain muscle mass after ACLR leading to persistent quadriceps muscle atrophy, which may potentiate greater strength deficits and poor functional recovery.

Isokinetic Assessment of Shoulder Joint Strength Ratios in Male Recreational Weightlifters: A Cross-Sectional Study.

Background Isokinetic strength imbalance is a risk factor for movement dysfunctions and injuries related to shoulder complex. The effects of recreational weightlifting on developing the imbalances between the shoulder muscles are not yet known. Objectives To investigate the isokinetic concentric shoulder muscle strength values (peak torque normalized to body weight) in recreational weightlifters (RWL) and to compare the shoulder muscles agonist/antagonist ratios with nonweightlifters. Methods Thirty male RWL with mean age, weight, height, and body mass index (BMI) of 21.56 years, 84.25 kg, 175.34 cm, and 26.51 kg/m2, respectively, matched with nonweightlifters served as a control group. The normalized concentric peak torque values of shoulder flexors, extensors, abductors, adductors, and internal and external rotators were measured at angular velocity 120°/sec by using Biodex isokinetic system. Moreover, the agonist/antagonist strength ratio for all muscle groups were calculated. Results The normalized peak torques of RWL group were significantly greater than the control group (p < 0.05). The abductor/adductor and external rotator/internal rotator ratios of the RWL were significantly lower than the control group (p = 0.008 and 0.009, respectively). Conversely, there was no significant difference between both groups in relation to the flexor/extensor ratio (p = 0.259). Conclusion These results suggested that the recreational weightlifting exercises place trainees at risk of muscle imbalances. Therefore, the restoration of a normal concentric abductor/adductor and external rotator/internal rotator strength ratios may decrease the risk of possible shoulder injury.

Isokinetic assessment of shoulder muscle strength for tennis players

Isokinetic assessment of shoulder muscle strength for tennis players

Test-Retest Reliability of Isokinetic Strength Measurements in Lower Limbs in Elderly.

Simple SummaryStrength is a critical factor for maintaining the quality of life of elderly. The gold standard is isokinetic dynamometry. Thus, this study intended to measure intra-session reliability in lower limbs. The results provide excellent values and data on what can be considered a real change after an intervention.Strength is essential for carrying out the usual activities of daily life. As there is a loss of strength in elderly, many treatments are based on delaying the loss of strength or maintaining it. Isokinetic dynamometry is the gold standard for assessing strength. It is essential that studies are conducted to allow us to identify the reliability of isokinetic strength assessments in older people. This study aimed to test the absolute and relative intra-session reliability of peak torque and work of a concentric knee extension-flexion performed at 60°/s in elderly. Fifty-two elderly subjects performed three repetitions of bilateral concentric knee extension-flexion at 60°/s using an isokinetic dynamometer. The relative and absolute reliability were calculated between the second and third repetition. The intra-class correlation coefficient values were between 0.94 and 0.98 for peak torque and work in all measures, which is considered “excellent”, except for left leg flexors in women, with values between 0.85 and 0.88, which is considered “good”. The standard error of measurement (SEM) percentage oscillated from 3.9% to 10.5%, with a smallest real difference (SRD) percentage of 10.9% to 29.2% for peak torque. The relative reliability of peak torque and work were excellent for all measures except flexors in women, evidencing the utility of isokinetic dynamometry for monitoring lower limb maximal muscle strength and work of concentric knee extension-flexion at 60°/s/s in the elderly. In addition, an SRD > 19.9% in peak torque and an SRD > 23.1% in work is considered a true change.

Consequences of Patellar Tendinopathy on Isokinetic Knee Strength and Jumps in Professional Volleyball Players.

Patellar tendinopathy (PT) in professional volleyball players can have an impact on their careers. We evaluated the impact of this pathology in this specific population in terms of isokinetic strength and jumping performances. Thirty-six professional male volleyball players (mean age: 24.8 ± 5.2) performed isokinetic knee assessments, single-leg countermovement jumps and one leg hop test. They filled out the Victorian Institute of Sport Assessment-Patella (VISA-P) score. Two groups were assessed: “PT group” (n = 15) and “control group” (n = 21). The VISA-P score was lower in the PT group (p < 0.0001). No difference was found between the isokinetic strength limb symmetry index and the jump performance limb symmetry index. The healthy legs of the control group were compared with the affected (PT+) and the unaffected legs (PT−) of the PT group. Compared with the healthy legs, both PT+ and PT− legs showed decreased values of quadriceps and hamstring strengths. Only PT+ legs scored lower than healthy legs in countermovement jumps and hop tests. No differences were found between PT+ and PT− legs for muscle strengths and jumps. A low correlation existed between quadriceps strength and jumping performances (r > 0.3; p < 0.001). Volleyball players with PT showed a decrease in the isokinetic knee strength. This strength deficit was found both on the symptomatic legs and the asymptomatic ones. Jumps were only significantly altered on the pathological legs. Highlighting that the unaffected limbs were also impaired in addition to the affected limbs may help provide a better adaptation of the rehabilitation management.

Knee Strength Outcomes in Adolescents by Age and Sex During Late-Stage Rehabilitation After Anterior Cruciate Ligament Reconstruction

Background:The incidence of anterior cruciate ligament (ACL) injuries have been consistently increasing in adolescents, with those who return to competitive sport having up to a 32% risk of a secondary ACL injury. There is limited evidence regarding knee strength outcomes in young adolescents following ACL reconstruction during late-stage rehabilitation when compared to older patient groups.Purpose:The purpose of this study was to 1) establish normative knee strength values according to age group in adolescent female and male patients during late-stage rehabilitation following ACLR and 2) determine whether strength differences exist between age groups.Methods:A retrospective review of adolescent patients who underwent primary ACL reconstruction was performed. Patients completed a standardized isokinetic (60°/sec) knee extension and flexion strength assessment during late-stage rehabilitation. Peak torque was normalized to the patient’s body mass (Nm/kg) and used to calculate Limb Symmetry Index (LSI). Analyses were conducted separately for female and male cohorts and grouped by early (11-14 years) and middle (15-17 years) adolescence. An independent samples t-test examined strength differences between age groups.Results:130 females (age=15.4 ± 1.4 years; days since surgery=239.0 ± 84.4) and 112 males (age=15.4 ± 1.5 years; days since surgery= 232.6 ± 91.2) were included. Normalized knee extension peak torque on the involved limb was reported for female (1.5 Nm/kg) and male (1.8 Nm/kg) cohorts. Differences between age groups in knee extension peak torque were found on the surgical and nonsurgical limbs in female (p = 0.02 – 0.05) and male (p<0.001 – 0.002) cohorts. No differences were found between age groups for either cohort when normalized to body mass (p = 0.30 – 0.89). Post hoc power analyses revealed 67% statistical power in the female cohort and 97% in the male cohort with an alpha level set to 0.05 based on the observed effect size for the differences in isokinetic knee extension/flexion peak torque between age groups.Conclusion:Early adolescents produced less knee extension and flexion peak torque compared to middle adolescents after ACLR, but no differences were found between age groups when normalized to body mass for female or male cohorts. Normalized knee extension strength in young adolescents may differ from older patients and should be considered in the rehabilitation process.TABLE 1:Patient Demographics - FemalesTABLE 2:Patient Demographics - MalesTABLE 3:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Females)TABLE 4:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Males)

The influence of angle-specific torque of the knee flexors and extensors on the angle-specific dynamic control ratio in professional female soccer players

ABSTRACT The purpose of this study was to assess whether dynamic torque ratios (DCR) from isokinetic strength assessments of eccentric knee flexors (eccKF) and concentric knee extensors (conKE) display differences when stratified into specific angle-specific DCR (DCRAST) groups. Fifty-two professional female soccer players (age 21.30 ± 4.44 years; height 166.56 ± 5.17 cm; mass 61.55 ± 5.73 kg) from the English Women’s Super League completed strength assessments of both lower limbs on an isokinetic dynamometer at 60°∙s−1. Angle-specific torque (AST) were used to calculate DCRAST to create sub-groups using clustering algorithms. The results identified for the dominant side that the Medium DCRAST group elicited significantly higher conKE AST when compared to Low and High DCRAST groups at increased knee extension (P ≤ 0.05). For the non-dominant side, the High DCRAST group had significantly higher and lower eccKF and conKE AST compared to the Low DCRAST group at increased knee extension (P ≤ 0.05). This study highlights that the inclusion of AST data may subsequently help practitioners to prescribe exercise that promotes strength increases at targeted joint angles. In turn, these approaches can be used to help reduce injury risk, identify rehabilitation responses and help inform return to play.

The Impact of 120 Minutes of Soccer-Specific Exercise on Recovery

ABSTRACT Purpose: The extra-time (ET) period of soccer is competed during fixture congested schedules with often limited recovery time between matches. The aim of this study was to assess muscle damage recovery following 90- and 120-min (i.e., incorporation of ET) of simulated soccer match-play. Methods: Twelve semiprofessional soccer players completed 90 and 120-min treadmill-based soccer-specific exercise in a counterbalanced order. Creatine kinase (CK), creatinine, urea, aspartate aminotransferase, perceived muscle soreness, pain pressure threshold, reactive strength index, countermovement jump height, and isokinetic strength assessments of eccentric knee flexors at 60, 180 and 270 deg‧s−1 were taken at baseline and immediately-, 24, 48 and 72-hr post-exercise to assess recovery. Results: No significant between-trial interactions except for CK were found. Pairwise comparisons detected a 53% increase in CK at 24-hr (455 ± 29 μ∙L−1) following 120-min of simulated match-play vs. the corresponding post 90-min time-point (299 ± 29 μ∙L−1; p < .01). The 120-min trial caused a 58% higher CK response at 72-hr (244 ± 25 μ∙L−1) vs. post 90-min comparisons (154 ± 29 μ∙L−1; p = .02). No interaction effects were detected for any other recovery variables. Creatine kinase and perceived muscle soreness remained elevated up to 72-hr in both trials (p < .01). Conclusions: These data indicate that 120 min of simulated soccer match-play delays the time-course of CK recovery up to 72-hr post-match. However, 120 min of simulated soccer has no additional impact on functional recovery and perceived muscle soreness vs. 90 min. Recovery should be investigated following 90- and 120-min of actual match-play.Trial registration The study was pre-registered on the Open Science Framework (DOI: 10.17605/OSF.IO/VGU6T Date: 10/06/2019).

Validity and reproducibility of the PPLP score in the follow-up of anterior cruciate ligament reconstruction in athletes

Objectives:In a context where psychological scores appear to have an increasing influence on the resumption of sports, it would also appear to be essential to evaluate the relevance of global scores with multiple criteria. The PPLP score (Psychological Physical Ligament Predictive score) enables an analysis of subjective, clinical and isokinetic muscle assessment items.Methods:We prospectively followed anterior cruciate ligament (ACL) reconstructions in several series for which we analyzed the validity of the score (763 patients), the reproducibility, the sensitivity to change, the relevance in the follow-up of ligamentoplasty (3,296 ligamentoplasties followed postoperatively) as well as the predictive nature in the resumption of sports (258 patients). The PPLP score has two parts: one (PPLP1) based on 100 points for postoperative follow-up and the other also based on 100 points (PPLP2) which is added to the first score for follow-up at a certain period of time after surgery to determine a new score of 200 points. We also tried to identify correlations with other scores in the literature (OAK, Lysholm, Tegner, KOOS, Arpeggio, IKDC Subjective and the Psychovitality Test).Results:We demonstrated the distinction of the items (r coefficient of 0.20) for construct validity. Intra-examiner and extra-examiner reproducibility was excellent, ranging from 0.92 to 1. The PPLP score changed in a statistically significant way during hospitalization and according to the operating lead time with phases of higher variation. Complicated clinical changes manifested in a low score, in particular neuro-algodystrophies (1.9%) with a mean PPLP1 of 80.33 while changes without complications (80.8%) had a mean score of 94.28 with a significant difference (p < 0.0001). The PPLP2 score correlated significantly with the resumption of competition (p = 0.012). A high score was associated with faster recovery. The optimal cut-off score was 176 (sensitivity 79.7% and specificity 49.3%). The results of the PPLP score were correlated with the other scores.Conclusion:The PPLP score was validated in terms of construction, reproducibility, and sensitivity in the follow-up of ACL ligamentoplasties. It provides indications on the quality of change and the possibilities of resuming sports. It is the only score that incorporates isokinetic assessments.

Reliability of Isokinetic Strength Assessments of Knee and Hip Using the Biodex System 4 Dynamometer and Associations With Functional Strength in Healthy Children.

BackgroundThis study aimed to analyze the reliability of concentric isokinetic strength assessments (knee and hip) using the Biodex System 4 in healthy children and assess the association with functional strength tests (sit-to-stand [STS], lateral-step-up [LSU]).Methods19 children (6–12 years) were included. Knee and hip flexion and extension, and hip abduction and adduction were tested at 60 and 90°/s.ResultsRelative and absolute reliability at 60°/s tended to show better results compared to those at 90°/s. Intra class correlations (ICCs) of knee flexion and extension at 60°/s were good (0.79–0.89). For hip flexion, extension, abduction and adduction at 60°/s ICCs were moderate to good (0.53–0.83). The smallest detectable change (SDC) values (expressed in %) were highly variable. The SDC% for knee flexion and extension and hip abduction at 60°/s were around 50%. Positive associations were found between hip extension and abduction isokinetic strength and the STS test.ConclusionConcentric isokinetic strength assessments in healthy children using the Biodex System 4 were found reliable for knee flexion and extension and hip abduction. Limited associations were found between concentric isokinetic strength tests and functional strength tests.

Knee and hip dynamic muscle strength in individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy: A case-control study

BackgroundThe primary aim of this study was to compare knee and hip dynamic muscle strength of individuals with femoroacetabular impingement (FAI) syndrome scheduled for hip arthroscopy with healthy controls. Our secondary aim was to compare hip and knee muscle strength between male and female patients with FAI syndrome.MethodsOne hundred and thirty-four individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy and 134 healthy controls matched for sex and age (within 5 years range) underwent an isokinetic assessment of knee extension and flexion and hip abduction, adduction, external rotation and internal rotation dynamic muscle strength. Two MANOVAs were conducted to compare isokinetic peak torque and total work between groups and sexes.FindingsIndividuals with femoroacetabular impingement syndrome demonstrated lower values of all variables representing knee and hip isokinetic peak torque and total work measures when compared to healthy controls, with differences ranging from 0.09 Nm/kg (95%CI: 0.06–0.12 Nm/kg) to 0.64 Nm/kg (95%CI: 0.49–0.79 Nm/kg). Female participants from both FAI syndrome and control group showed less knee and hip muscle strength compared to male participants. There was no significant interaction between group and sex regarding knee or hip isokinetic peak torque and total work (p > 0.05).InterpretationIndividuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy present impairments in knee or hip dynamic muscle strength when compared to controls. Female participants present less knee and hip muscular strength compared to male participants, these between-sex differences are similar for both FAI syndrome and control group participants.

The Hamstring and ACL Injury Incidence during a Season Is Not Directly Related to Preseason Knee Strength Ratios in Elite Male Soccer Players

Background and Objectives: The aim of this study was to identify preseason isokinetic strength differences in the knee flexors and extensors and their ipsilateral/bilateral ratios and, furthermore, to compare the results among players who subsequently overcame a hamstring strain injury (HSI) or anterior cruciate ligament (ACL) rupture during the season and those who did not. Materials and Methods: A total of 134 professional soccer players underwent isokinetic strength assessment at a velocity of 60°·s−1 (knee flexors and extensors) for the dominant and non-dominant lower limb to determine preseason peak torque values and bilateral and ipsilateral strength ratios. Subsequently, the incidence of injuries during the season was recorded, and players were divided into groups according to ACL rupture injuries (n = 10), hamstring strains (n = 10), and a control group of non-injured players who were selected on a random basis (n = 20). A retrospective approach was used to analyze and compare the preseason strength characteristics and whether some variance among groups was relevant among the injured leg and non-injured leg groups. Results: The results of our study show that low-angular velocity preseason testing did not result in a player’s HSI or ACL injury during the season. The difference between the monitored groups ranged from 1.5% to 3%. The comparison showed low evidence for significant differences. Conclusions: An angular velocity of 60°·s−1 within concentric muscle contraction alone was not linked to subsequent injury of the hamstring or anterior cruciate ligament and acted as an insufficient factor of injury risk in adult professional soccer players.

Associations of serum IL-6 with muscle, bone, and adipose tissue in women

This cross-sectional study examined the associations between serum interleukin-6 (IL-6) and muscle, bone, and fat parameters in recreationally active women. One-hundred forty-five women (48.7 ± 17.8 years; 164.4 ± 7.1 cm; 66.8 ± 10.7 kg; and 24.7 ± 3.9 kg/m2) underwent dual energy x-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) assessments to determine total and regional muscle, bone, and fat parameters. Muscle performance of the knee extensors was examined via isometric, isotonic, and isokinetic dynamometry assessments, and serum IL-6 was measured via enzyme linked immunosorbent assay. Serum IL-6 was inversely associated with thigh muscle cross-sectional area (mCSA, r = -0.28, p < 0.01); isometric strength (r = -0.19, p < 0.05); hip areal bone mineral density [aBMD] (r = -0.18, p < 0.05); trochanter aBMD (r = -0.23, p < 0.01); total body aBMD (r = -0.20, p < 0.05); cortical volumetric bone density at 38 and 66% tibia (r = -0.18 and r = -0.19, respectively, both p < 0.05), and 66% cortical thickness (r = -0.17, p < 0.05). These associations were present after adjusting for age, BMI, and physical activity. Thigh mCSA was significantly lower in the tertile possessing the greatest IL-6 compared to the lowest tertile (p < 0.01); after adjusting for age, body mass index, and physical activity. Collectively, these observations indicate that IL-6 is inversely associated with skeletal muscle and bone parameters independent of relevant confounders. These observations bolster the prognostic value of serum IL-6.

Characterization of Motor Performance in 200 Normal Ankles Through Isokinetic Evaluation

Category:Ankle; SportsIntroduction/Purpose:The isokinetic test has been used diffusely as a way to evaluate the functional results after the rehabilitation of musculoskeletal injuries. In the ankle, in particular, most studies are related to lateral ligament injuries and Achilles tendon's injuries. However, different protocols are used and a lack of normative values is observed in the literature. The aim of this work is to perform a global isokinetic evaluation on healthy ankles in order to propose reference values for future patients.Methods:We evaluated 100 participants (200 ankles) using the Biodex 3 System for the eversion, inversion, dorsiflexion and plantar flexion movements of the ankle. The sample consisted of individuals aged 20-60 years, with an active life and practice of recreational physical activity (non-athlete) and without previous injuries. Five repetitions for strength (N / m) and work (J) at a speed of 30° / sec and 10 repetitions for power (W) at a speed of 120° / sec were performed in our protocol. Agonist / antagonist ratio and the Muscle Deficiency Index, which globally assesses the balance between the sides for each movement, were also evaluated, as well as the demographic variables. Different statistical analyzes were performed for each parameter.Results:The mean age was 38.5 years and BMI 25.8 (CI 2.7 and 0.8 respectively). The non-dominant side was consistently stronger (higher peak torque) in all movements (p <0.001 -). The mean values obtained for force in each movement were 29.9N / m (CI 1.4) for eversion, 34.8N / m (CI 1.6) for inversion, 48.6N / m (2.0) for dorsiflexion and 140.2 N / m (CI 6.1) for plantar flexion. There was no correlation between age or BMI with the maximum torque (N / m). The ratio of eversors / inverters was 88.8% (CI 3.1) and that of dorsiflexors / plantar flexors was 36.1% (1.3). The Muscle Deficiency Index showed a balance between the sides for each movement (p 0.062), with an average global difference of less than 10% between them (eversion 8.66 [CI 3.17], inversion 4.2 [3, 48], dorsiflexion 3.41 [3.04] and plantar flexion 5.18 [2.51].Conclusion:As far as we know, this is the largest isokinetic assessment of normal ankles ever performed. The sample, although not stratified, was considered homogeneous (coefficient of variation <50%), which allows to propose several normative values for a non-athlete population in the isokinetic evaluation. It would be interesting to compare these data in the future with the functional results in patients after the treatment of certain injuries.

Isokinetic and functional shoulder outcomes after arthroscopic capsulolabral stabilization

IntroductionShoulder stability is secured by dynamic and static stabilizers. Rotator cuff is responsible for dynamic stabilization. In cases of shoulder instability their activity is disturbed. Capsulolabral repair restores mainly static stabilization. This surgery treatment technique of shoulder instability was first described by Bankart in 1923. His idea, with further modifications, is commonly used up to this day. Evaluation of muscle shoulder recovery after stabilization should be one of the important criteria to allow patient to return to sport and work. However, not much isokinetic assessment after capsulolabral repair was described. The aim of this study were the following: the comparative assessment of the shoulder rotatory strength in patients following arthroscopic capsulolabral repair of unilateral anterior traumatic instability and clinical assessment with comparison of pre and post-operative results.Material and methodsForty-five patients, 14 women and 31 men, with an average follow-up of 4.4 years were tested bilaterally for internal and external rotation strength at four angular velocities. ASES and UCLA tests were collected before and after surgery.ResultsThe values of peak moment and muscle power parameters were slightly lower for an operated shoulder in comparison to a healthy shoulder for the external rotation. Total work parameter in external rotation was significantly lower for the operated shoulder in comparison to the non-operated side. The internal/external muscle group balance was lower for the operated shoulder in comparison to reference values in the women group. Furthermore, both ASES and UCLA scores were significantly higher after operation.ConclusionsAfter arthroscopic capsulolabral shoulder stabilization, slight differences in isokinetic evaluation, especially in external shoulder rotation, occur. It affects rotators muscle balance. In functional evaluation significant improvement in shoulder function occurs.