Isokinetic Assessment Research Articles

Does combined anterior cruciate ligament and anterolateral ligament reconstruction improve return to sport?

Only 50-65% of patients return to their previous sporting level after ACL rupture. The literature reports a reduced rate of graft rupture when an anterolateral ligament reconstruction (ALLR) is associated with ACL reconstruction. ACL reconstruction combined with ALL allows a higher return to sport at pre-injury level than isolated reconstruction in patients playing pivot-contact sports. A retrospective, single-centre study between 2012 and 2020 comparing reconstruction by hamstring tendon technique, isolated ACLR vs ACL with ALLR. An isokinetic test was performed at 6months post-operatively and patients were re-contacted at a minimum 2-year follow-up to assess their level and delay to return to sport, graft rupture rate and functional evaluation. 83 patients were included, 42 in ACLR group and 41 in ACL + ALLR group. Four patients were lost to follow-up and 79 patients were analysed. No significant difference was found on the level of return to sport (28.2% vs. 42.5%; p = 0.18), return to competition (43% vs. 60%; p = 0.18), delay to sports return, isokinetic assessment, functional scores, but a significant difference was found on graft rupture rate in favour of ALLR (12.8% vs. 0%; p = 0.02). In our study, the addition of an ALL to ACL reconstruction did not improve pre-injury sports recovery or return to competition. Cohort study, level of evidence 4.

Characterization of Motor Performance in 200 Normal Ankles Through Isokinetic Evaluation

Category: Ankle; Sports Introduction/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 30º / sec and 10 repetitions for power (W) at a speed of 120º / 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 in 69 men and 31 women. In 78 participants, the dominant ankle was the right one. The non-dominant side was consistently stronger in all movements (p < 0.001). The mean values obtained for force in each movement were 29.9N/m for eversion, 34.8N/m for inversion, 48.6N/m for dorsiflexion and 140.2 N/m for plantar flexion. Such parameters for men and women were also obtained (p < 0.001) and there was no correlation between age or BMI with the maximum torque through Spearman's Correlation. The ratio of eversors/inverters was 88.8% and that of dorsiflexors/plantar flexors was 36.1%. The Muscle Deficiency Index showed a balance between the sides for each movement, with an average global difference of less than 10% between them. 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.

The Effect of an Exercise Program on the Biomechanics of the Shoulder Girdle in Overhead Shooting in High-level Handball Players

Handball athletes are subjected to high loads, especially during the process of throwing or shooting overhead. These athletes often complain of pain and report unexplained loss of throwing velocity and throwing control. Shoulder dyskinesia and overuse syndrome have been identified as risk factors among elite handball athletes. Understanding the dynamics and kinematics of the throwing phase is vital for the exercise professional. This study evaluates the effect of an interventional exercise program on shoulder girdle biomechanics and overhead shooting. The sample consisted of 20 high level handball athletes from Greece. The athletes were divided into two groups: 10 in the study group, who were given the exercise program, and 10 in the control group, who only engaged in in-team handball training. Before and after the program, the following measurements were performed: a) angular measurements of abduction, adduction, flexion and extension of the shoulder; b) isokinetic evaluation of abduction flexion and adduction extension of the shoulder joint, at three angular velocities (60°/sec, 180°/sec and 300°/sec). Inferential statistics showed that there was a statistically significant difference in angular measurements with a reduction in range of motion for 10 of the study group. In the isokinetic assessment there was a statistically significant difference, in the 180°/sec velocities in flexion and extension, and in the deficit of flexion of both shoulders. In conclusion, the interventional exercise program had, to some extent, a beneficial effect on muscle strengthening of the shoulder girdle. The results of this study may suggest training guidelines, provide important information to exercise professionals, and provide feedback to handball athletes.

Differences in Strength and Fatigue Resistance of Scapular Protractors and Retractors Between Symptomatic and Asymptomatic Dyskinesis.

Scapular dyskinesis is a shoulder dysfunction that can be asymptomatic or associated with pain or weakness. Reduced strength and fatigue resistance of the scapular protractor and retractor muscles that stabilize the scapula might contribute to dyskinesis. To determine the strength and fatigue resistance profiles of participants with symptomatic or asymptomatic scapular dyskinesis and compare them with healthy control (HC) individuals using isokinetic assessment. Cross-sectional study. University hospital. Twenty HC individuals and 21 overhead athletes with symptomatic (n = 10) or asymptomatic (n = 11) scapular dyskinesis. Strength (peak torque, maximum work), fatigue resistance (total work), and protraction:retraction ratios measured during a closed chain isokinetic protocol (40 repetitions in concentric mode at 24.4 cm/s). The scapular protractors' strength and fatigue resistance were higher (P < .01) in HC individuals (peak torque = 5.0 ± 0.9 N/kg, maximum work = 2.4 ± 0.5 J/kg, total work = 72.4 ± 0.6 J/kg) than in asymptomatic (peak torque = 3.4 ± 0.7 N/kg, maximum work = 1.7 ± 0.4 J/kg, total work = 50.0 ± 13.7 J/kg) or symptomatic (peak torque = 3.8 ± 0.6 N/kg, maximum work = 1.8 ± 0.3 J/kg, total work = 58.1 ± 12.9 J/kg) dyskinetic participants. The symptomatic dyskinetic group presented the highest retractor strength and fatigue resistance (P < .01) values (peak torque = 5.2 ± 0.6 N/kg, maximum work = 2.9 ± 0.8 J/kg, total work = 87.7 ± 22.7 J/kg), followed by the HC individuals (peak torque = 4.7 ± 1.0 N/kg, maximum work = 2.1 ± 0.5 J/kg, total work = 65.3 ± 17.9 J/kg) and the asymptomatic dyskinetic participants (peak torque = 3.9 ± 1.0 N/kg, maximum work = 1.9 ± 0.6 J/kg, total work = 58.6 ± 18.5 J/kg). The protraction:retraction ratios showed a gradual decrease (P < .001) from the HC individuals (1.1) to the asymptomatic (0.9) and symptomatic (0.7) dyskinetic participants. Scapular dyskinesis is characterized by weaker scapular protractors and reduced agonist:antagonist ratios, especially when patients are symptomatic. Targeting the scapular protractors to achieve a better balance of scapular musculature in rehabilitation and strengthening programs may improve shoulder symptoms and function, but more interventional studies are required.

Post-Operative Modified All-Inside ACL Reconstruction Technique's Clinical Outcomes and Isokinetic Strength Assessments.

Anterior cruciate ligament (ACL) injuries are very common among the athletic population. ACL reconstruction (ACLR) performed because of these injuries is one of the procedures performed by orthopedic surgeons using different grafting methods. This study aims to compare the data related to post-operative 6-month isokinetic strength values, strength-related asymmetry rates, time parameters, and joint angle in athletes who underwent ACLR with the Modified All-inside (4ST) technique, on both the healthy knee (HK) and the ACLR-applied sides. A total of 20 athletes from various sports on whom the 4ST ACLR technique had been applied by the same surgeon were evaluated retrospectively. Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores of the patients were obtained pre-operative and at 6 months post-operative. Isokinetic knee extension (Ex) and flexion (Flx) strengths on the HK and ACLR sides of the patients were evaluated with a series of four different angular velocities (60, 180, 240, and 300°/s). In addition to peak torque (PT) and hamstring/quadriceps ratio (H/Q) parameters, the findings were also evaluated with additional parameters such as joint angle at peak torque (JAPT), time to peak torque (TPT), reciprocal delay (RD), and endurance ratio (ER). There was a significant improvement in the mean Lysholm, Tegner, and IKDC scores after surgery compared with pre-operative levels (p < 0.05). As for PT values, there were significant differences in favor of the HK in the 60, 180, and 300°/s Ex phases (p < 0.05). In terms of the H/Q and (hamstring/hamstring)/(quadriceps/quadriceps) (HH/QQ) ratios, there were significant differences at 300°/s (p < 0.05). In terms of JAPT, there were significant differences in the 300°/s Ex and 180°/s Flx phases (p < 0.05). In terms of TPT, there were significant differences in the 300°/s Ex phase (p < 0.05). In terms of RD and ER, no significant difference was observed between the HK and ACLR sides at any angular velocity. Although differences were observed in PT values, particularly in the Ex phase, this did not cause a significant change in H/Q ratios. Similar results were observed for additional parameters such as JAPT, TPT, RD, and ER. The results show that this ACLR technique can be used in athletes in view of strength gain and a return to sports.

The Influence of Isokinetic Trunk Flexor and Extensor Strength on Dynamic Balance in Children

This study assessed whether trunk flexor and extensor strength were predictors of time to stability (TTS) and center of pressure (CoP) during hop and hold tasks in children. Seventeen boys (age, 10.1 ± 1.6 years; height, 1.45 ± 0.11 m; mass, 26.7 ± 7.83 kg) undertook isokinetic strength assessments of concentric and eccentric trunk flexors/extensors at 60°/s, and anterior/medial hop tasks. Hierarchical multiple regressions determined whether concentric and eccentric trunk flexor/extensor peak torques predict TTS using a composite score (CompX CompY CompZ) and CoPX and CoPY. Concentric trunk flexors were the strongest predictor for TTS CompXY, with concentric flexion and eccentric extension predicting TTS CompY. All muscle actions were also strong predictors for CoPY during hop tasks. These findings have implications for the assessment of trunk musculature strength and measures of postural control within a young healthy population. The development of trunk musculature strength may aid improvements in dynamic balance tasks in children, with implications for fall and injury risk. To improve trunk musculature strength and the potential to maintain postural control, a combination of concentric and eccentric exercises with other training modalities appears relevant due to the increased relevance to the demands of balance maintenance.

Isokinetic Training After A Matrix-Induced Autologous Chondrocyte Implantation Procedure: A Case Study

BACKGROUND: Matrix-induced autologous chondrocyte implantation (MACI) is an effective surgical procedure to repair defective cartilage. CASE PRESENTATION: This case study examined the influence of an isokinetic training program on muscle strength, size, and vertical jump performance for a young female adult after a MACI procedure. The subject completed an isokinetic training program 3 days/week for 12 weeks. Weekly assessments included isometric and isokinetic assessments of thigh muscle strength and power, ultrasound assessments of quadriceps and hamstrings muscle size, and force plate assessments of bilateral and unilateral vertical jump performance. OUTCOME AND FOLLOW-UP: Thigh muscle size 15% to 23%. Thigh muscle strength increased from 19% to 105%, whereas power increased from 29% to 121%. Bilateral and unilateral vertical jump performance increased from 6% to 93%. DISCUSSION: This study demonstrates that a 12-week isokinetic training program appears effective for increasing muscle strength, size, and vertical jump performance within the year following a MACI procedure. JOSPT Cases 2023;3(3):150-157. Epub: 20 June 2023. doi:10.2519/josptcases.2023.11617

Isokinetic strength assessment of trunk muscle and its relationship with spinal-pelvic parameters in patients with degenerative spinal deformity.

The incidence rate of degenerative spinal deformity (DSD) has gradually increased in the elderly. Currently, the relationship between the functional status of trunk muscle and the spinal-pelvic parameters of DSD patients remains unclear. This paper aims to explore the relationship between the two factors and provide new clues for exploring the mechanism of the occurrence and development of DSD. A total of 41 DSD patients treated in our hospital (DSD group) and 35 healthy volunteers (control group) were selected. Muscle strength was evaluated using an IsoMed-2000 isokinetic dynamometer, and the trunk flexor and extensor peak torque (PT) of subjects was measured at a low, medium, and high angular velocity of 30∘/s, 60∘/s, and 120∘/s, respectively. Hand grip strength (HGS) was assessed using an electronic grip dynamometer and Surgimap software was used to measure the spinal-pelvic parameters, including the sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence rate (PI), and PI-LL, and the relationship between trunk muscle function and various parameters was analyzed. Under the three angular velocities, the flexor and extensor PT values in the DSD group were lower than those in the control group, and only the extensor PT showed a statistically significant difference (P< 0.05). There was no significant difference in HGS between the two groups (P> 0.05). In the DSD group, the extensor PT at 30∘/s was significantly negatively correlated with SVA (P< 0.05). At 60∘/s and 120∘/s, the extensor PT was significantly negatively correlated with SVA and PT (P< 0.05). Trunk extensor strength is significantly lower in DSD patients than in normal controls. The decline in trunk extensor strength in DSD patients is a type of local muscle dysfunction more closely related to the deformity, which is likely involved in the compensatory mechanism of DSD and may reflect the overall imbalance of the trunk.

Isokinetic Assessment of Knee Flexor and Extensor Strength and Lower Extremity Flexibility Assessment of an NCAA Division III Men's Soccer Team.

Strength imbalances and flexibility deficits of the hamstrings and hip flexors have been identified as potential risk factors for hamstring injuries, but research on athletes at the Division III level are limited, potentially due to a lack of resources and technology. The purpose of this study was to conduct isokinetic and flexibility assessments to screen male soccer athletes at risk of sustaining a hamstring injury. Observational cohort. Standardized isokinetic testing of concentric muscle performance, measured by peak torque of the quadriceps and hamstrings and hamstring-to-quadriceps ratios, was conducted using a Biodex isokinetic dynamometer at speeds of 60 and 180°/sec.Additionally, the Active Knee Extension (AKE) test and the Thomas test were performed bilaterally to objectively measure flexibility. Paired sample t-tests were used to compare left and right lower extremities for all outcomes, with the level of significance set at p<0.05. Participants were ranked for risk and given a set of exercises sourced from the FIFA 11 Injury Prevention Program. At 60°/sec, the mean PT/BW bilateral deficit was 14.1% for extension and 12.9% for flexion. At 180°/sec, the mean deficit was 9.9% for extension and 11.4% for flexion. The team's average for left and right H:Q ratios for each speed were 54.4 and 51.4 at 60°/sec and 61.6 and 63.1 at 180°/sec, respectively. The team's average AKE range of motion was 158° for the left leg and 160° for the right leg. The mean Thomas test measurements were 3.6° away from the neutral position on the right and 1.6° on the left, with nine positive tests. There were no statistically significant differences between left and right knee extension or flexion PT/BW or H:Q ratios at either speed. There was no significant difference between left and right AKE measurements (p=0.182). The results of this screening suggest that isokinetic testing and flexibility testing may be useful to identify non-optimal strength ratios and flexibility deficits in male collegiate soccer players. The benefits of this research have direct implications, as participants received both their screening data and a set of exercises aimed to help decrease their injury risk, in addition to the offering data that is useful for determining what normative values for flexibility and strength profiles might look like for Division III male soccer players. Level 3.

Age-, Sex-, and Graft-Specific Reference Values From 783 Adolescent Patients at 5 to 7 Months After ACL Reconstruction: IKDC, Pedi-IKDC, KOOS, ACL-RSI, Single-Leg Hop, and Thigh Strength.

OBJECTIVE: To describe age-, sex-, and graft source-specific reference values for patient-reported, physical function, and strength outcome measures in adolescents at 5 to 7 months after anterior cruciate ligament reconstruction. DESIGN: Cross-sectional study. METHODS: Data were collected at 3 universities and 2 children's hospitals. The participants completed at least one of the International Knee Documentation Committee (IKDC) Subjective Evaluation Form, Pediatric IKDC (Pedi-IKDC), Knee Injury and Osteoarthritis Outcomes Score (KOOS), and Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale. Participants also completed single-leg hop tests and/or isokinetic quadriceps and hamstrings strength assessments (at 60°/s). Reference values were summarized using descriptive statistics and stratified for age, sex, and graft source. RESULTS: Reference values were reported for common patient-reported outcomes and measures of physical function and strength from 783 participants (56% females, age = 16. 4 ± 2.0 years) who were in early adolescence (12-14 years, N = 183, 52% females), middle adolescence (15-17 years, N = 456, 58% females), or late adolescence (18-20 years, N = 144, 55% females). Three hundred seventy-nine participants (48.4%) received a bone-patellar tendon-bone autograft, 292 participants (37.3%) received hamstring tendon autograft, and 112 participants (14.3%) received autograft or allograft from an alternative source. CONCLUSION: Reference values for common patient-reported outcomes and measures of physical function and strength differed depending on a patient's age, sex, and graft source. Using patient-specific reference values, in addition to previously described age-appropriate cutoff values, may help clinicians monitor and progress patients through rehabilitation and return to physical activity after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 2023;53(4):1-8. Epub: 23 January 2023. doi:10.2519/jospt.2023.11389.

Characterization of Static Strength, Vertical Jumping, and Isokinetic Strength in Soccer Players According to Age, Competitive Level, and Field Position.

Muscular strength is strongly related to speed and agility tasks, which have been described as the most decisive actions preceding goals in the soccer game. This study aimed to characterize the players' strength indicators and to analyze the variation associated with age, competition level, and positional role. Eighty-three male soccer players from A team (n = 22), B team (n = 17), U-23 (n = 19), and U-19 (n = 25) participated in this study. Handgrip strength was assessed using a hand dynamometer (Jamar Plus+), countermovement jump (CMJ) and the squat jump (SJ) were evaluated using Optojump Next, and a Biodex System 4 Pro Dynamometer was used to assess the isokinetic strength of knee extension/flexion. Team A players showed increased lower-body strength compared to their peers, mainly through their increased vertical jumping capacity (i.e., CMJ and SJ; ps < 0.019), and superior performance in isokinetic assessments (i.e., peak torque, total work, and average power). Overall, older players outperformed their younger peers regarding vertical jumping, static strength, and average power in isokinetic strength (ps < 0.005). This study emphasizes the superior strength levels of professional soccer players compared with their lower-division peers, even after controlling by age. This information is of great value to sports agents and coaches, underlining the need to design and include strength-specific content during soccer training.

Predictors of linear sprint performance in professional football players.

The purpose of this study was to analyze the relationship between sprint performance (time), and strength and power capabilities in football players. A total of 33 professional Portuguese football players performed isokinetic strength assessments, countermovement jumps (CMJ), squat jumps (SJ), and 10, 20 and 30 m sprints. Pearson's correlation (r) was used to determine the relationships between variables. Concentric knee extensor torque at 180° · s-1 was largely-to-very largely correlated with 10 m (r = -0.726), 20 m (-0.657) and 30 m sprints (r = -0.823). Moderate inverse correlation were observed between CMJ (r = -0.425 and r = -0.405) and SJ height (r = -0.417 and r = -0.430), and 20 m and 30 m sprint performance, respectively. Multiple linear regression combining KEcon 180° · s-1 and KFcon 180° · s-1 demonstrated that the model was significant for predicting 10 m sprint time (F (2, 8) = 5.886; R 2 = 0.595). The model combining SJ, CMJ and KEcon 180° · s-1 was also significant for predicting 20 and 30 m sprint times (F (3, 7) = 2.475; R 2 = 0.515 and F (3, 7) = 5.282; R 2 = 0.562; respectively). In conclusion, peak torque at higher velocities and vertical jump performance correlates significantly with linear sprint performance (time). For practitioners seeking to improve linear sprint performance in football players, evaluation of high speed strength and vertical jump indices should be undertaken.

Pre- and Post-Operative Hamstring Autograft ACL Reconstruction Isokinetic Knee Strength Assessments of Recreational Athletes.

Background and Objectives: Anterior cruciate ligament (ACL) injuries are common injuries with a high incidence among people with high physical activity levels. Therefore, ACL reconstruction (ACLR) is one of the most common surgical procedures performed in sports medicine. This study aims to compare the pre- and 6-month post-operative isokinetic knee strengths in healthy (HK) and ACL knees of patients who underwent semitendinous/gracilis (ST/G) ACLR. Materials and Methods: A retrospective cohort of 21 recreational athletes who underwent ST/G ACLR by the same surgeon were evaluated. The pre- and 6-month post-operative isokinetic knee extension (Ex) and flexion (Flx) strengths of the HK and ACLR patients were evaluated in a series consisting of three different angular velocities (60, 180 and 240°/s). Of all the findings, peak torque (PT) and hamstring/quadriceps (H/Q) parameters were evaluated. Results: There was a significant improvement in post-operative Lysholm, Tegner and IKDC scores compared to pre-operative scores (p < 0.05). There were significant differences in pre-operative and post-operative knee Ex and Flx strengths at angular velocities of 60°, 180° and 240°/s in both the ACLR and HK groups (p < 0.001). There was no significance at 240°/s Flx for ACLR (p > 0.05). As for H/Q ratios, there was a significant difference between pre- and post-operative values only at 60°/s angular velocity in both ACLR and HC (p < 0.005). Conclusions: The pre-operative and 6-month post-operative results of the ST/G ACLR showed that there was a high level of recovery, particularly in quadriceps strength, while the increase in strength was less in the hamstring. The significance observed at 60°/s in H/Q ratios was within normal ranges. It can be argued that the ST/G ACLR method is feasible for people with high physical activity levels and for athletes.

Reliability of isokinetic hip abductor and adductor strength measurements: A systematic review and meta-analysis

The aims of this study were to: (I) examine the reliability of the abduction and adduction isokinetic strength measurements in healthy subjects and athletes; (II) determine which position is the most valid and reliable for strength measurement; and (III) determine the most reliable velocity to assess hip abductor and adductor strength. The databases used were Web of Science, SCOPUS, MedLine and PubMed. The metafor package of R software was used to conduct meta-analysis. A total of 767 studies were identified through a search of electronic databases, of which 10 were included in this meta-analysis. The main finding of the study revealed; (I) the reliability of isokinetic force measurement is good in abduction (ICC = 0.83) and adduction (ICC = 0.81); (II) standing position presents good reliability in abduction (ICC = 0.83) and adduction (ICC = 0.79); (III) the lateral position presents good reliability in abduction (ICC = 0.83) and adduction (ICC = 0.82); (IV) the velocity of 60°/s (ICC = 0.84), 90°/s (ICC = 0.84) and 120°/s (ICC = 0.86) show good reliability for abduction, and; (V) the velocity of 30°/s (ICC = 0.76), 60°/s (ICC = 0.83), and 120°/s (ICC = 0.89) show good reliability for adduction. Many factors influence the reliability of isokinetic assessments of the hip abductors and adductors, the best known of which are body position, isokinetic velocity, and type of muscle contraction. And although most of the researchers opt for the evaluation in lateral position, and at low velocities, our results conclude that the standing position, at a velocity of 120°/s is a better alternative to evaluate these movements (ABD-ADD), and not only because of its good reliability, but also because of the similarity of the evaluation with the gestures developed within the sport.

Shoulder Internal Rotator Strength as Risk Factor for Shoulder Pain in Volleyball Players.

The aim of this study was to identify the intrinsic factors that could increase risk of shoulder pain in adolescent volleyball players. Twenty-eight young male volleyball players (between 14 and 18 years old) participated in this study. Athletes were submitted to: isokinetic muscle strength assessment of shoulder rotator muscles, ball service speed assessment, anterior and posterior drawer test, apprehension test, groove sign and scapular dyskinesia test. Athletes were followed for 16 weeks to monitor the presence of shoulder pain. All athletes were submitted to the same training protocol. During the 16 weeks, 28.5% of the athletes (n=8) experienced shoulder pain in the dominant limb higher than 3 according to Numerical Rating Scale criteria; 71.5% of the athletes (n=20) did not experience pain, or pain equal or lower than 3. The main result of our study was that the odds of feeling pain higher than 3 was significantly higher among players who presented higher values for internal rotation peak torque (OR=1.113, CI 95%=1.006 to 1.232 and p=0.038). The odds of feeling pain increased by 11% for every N·m of the internal rotator muscles. Pre-season isokinetic rotator strength assessments can help identify adolescent volleyball players at increased risk of a shoulder injury.

Acute effects of NIV on peripheral muscle function and aerobic performance in patients with chronic obstructive pulmonary disease: a pilot study

BackgroundNon-invasive ventilation (NIV) reduces respiratory load and demands on peripheral muscles.MethodsThis study aims to evaluate the acute effects of bi-level NIV on peripheral muscle function during isokinetic exercise and aerobic performance in chronic obstructive pulmonary disease (COPD) patients. This is a pilot crossover study performed with a non-probabilistic sample of 14 moderate to very severe COPD patients. Procedures carried out in two days. Dyspnea, quality of life, lung function, respiratory muscle strength, functional capacity (6-min walk test—6MWT), and isokinetic assessment of the quadriceps were assessed. Blood samples (lactate, lactate dehydrogenase, and creatine kinase concentration) were also collected. Right after, NIV was performed for 30 min (bi-level or placebo, according to randomization) followed by new blood sample collection, 6MWT, and isokinetic dynamometer tests. Before and after evaluations, the subjective perception of dyspnea and fatigue in the lower limbs was quantified. After a wash-out period of seven days, participants returned, and all assessments were performed again.ResultsNIV showed improvements in perceived exertion and dyspnea after isokinetic exercise (p < 0.02 and p < 0.05, respectively).ConclusionsNIV improves the perception of dyspnea and fatigue during the isokinetic exercise.

Effects of a Thorstensson fatiguing protocol on isometric and isokinetic performance

OBJECTIVE: Having participants perform 50 maximal isokinetic contractions, as introduced by Thorstensson and Karlsson (1976), is to this day one of the most commonly used fatigue protocols. Purpose: To determine to what extent a Thorstensson fatiguing protocol affects isokinetic and isometric performance characteristics. METHODS: Twenty-five college-aged men performed an isokinetic fatigue protocol consisting of 50 maximal elbow flexions at a moderate speed (180∘⋅s-1). Pre- and post-tests were used to calculate fatigue indices (FI%) for the following variables: isometric and isokinetic peak torque (PT), isometric rate of torque development (RTD), and maximum acceleration (ACCmax). RESULTS: Each of the four dependent variables significantly decreased with fatigue (each demonstrated p&lt; 0.001), but not of the same magnitude. Isometric PT FI (-18.7%) was significantly less than isokinetic PT FI (-45.1%, p⩽ 0.001) and ACCmax FI (-26.3%) was significantly less than isometric RTD FI (-54.9%, p⩽ 0.001). There was a significant positive relationship between isometric and isokinetic PT FI% (r= 0.60, p&lt; 0.002) as well as between isometric PT FI% and RTD FI% (r= 0.40, p&lt; 0.046). There was no significant relationship observed between RTD FI% and ACCmax FI% nor between isokinetic PT FI% and ACCmax FI%. CONCLUSIONS: This investigation observed different patterns of response in maximal strength between isometric and isokinetic assessments following a isokinetic fatigue protocol. Additionally, the ability to rapidly generate strength and velocity had significantly different responses to fatigue between isometric and dynamic assessments. Due to these different responses, we recommend that assessments of fatigue at least include the same testing modality as the modality of the fatigue protocol.

Isokinetic Evaluation in a Large Cohort of Normal Ankles

Category: Ankle; Sports; Other Introduction/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 30o / sec and 10 repetitions for power (W) at a speed of 120o / 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) in 69 men and 31 women. In 78% of participants, the dominant ankle was the right one. The non-dominant side was consistently stronger (higher peak torque) in all movements (p&lt;0.001 - Wilcoxon Test). The mean values obtained for force in each movement were 29.9N/m for eversion, 34.8N/m (CI 1.6) for inversion, 48.6N/m (2.0) for dorsiflexion and 140.2 N/m for plantar flexion. Such parameters for men and women were also obtained (p&lt;0.001) and there was no correlation between age or BMI with the maximum torque (N/m) through Spearman's Correlation. The ratio of eversors / inverters was 88.8% (CI 3.1) and that of dorsiflexors / plantar flexors was 36.1% (1.3). Limb symmetry Index were &gt;= 90% between sides in all four moviments (91,99% for eversion, 98,57% for inversion, 96,96% for dorsiflexion and 94,72% for plantarflexion). Conclusion: The non-dominant side was stronger in this evaluation of the two hundred healthy ankles. However, this difference was within the expected range for the limb symmetry index and for the MDI, showing that limb dominance is not relevant for the isokinetic assessment of the ankle. In the studied sample, the demographic variables (except gender) did not show any correlation with the evaluated parameters, especially with the maximum torque. Normative values of torque forces and agonist/antagonist balances were proposed. The results have implications for rehabilitation protocols and criteria for returning to sports.

Effect of pulsed electromagnetic field as an intervention for patients with quadriceps weakness after anterior cruciate ligament reconstruction: a double-blinded, randomized-controlled trial

BackgroundThe ultimate goal of anterior cruciate ligament reconstructions (ACLR) is to fulfil the return-to-play (RTP) criteria. Quadriceps muscle strength is one of the key determinants for a patient’s successful return-to-play after ACLR. Quadriceps muscle atrophy can persist beyond the completion of the rehabilitation program in almost half the patients and the reason behind this is still unknown. There are emerging evidences showing that pulsed electromagnetic field (PEMF) can modulate mitochondrial activities for muscle gain. PEMF exposure on top of regular exercise training may promote muscle regeneration and tissue healing.MethodsThis is a double-blinded, randomized controlled trial to investigate the effects of PEMF treatment during the postoperative period on quadriceps muscle strength in ACL injured patient. Adult patients (aged 18–30) with a unilateral ACL injury, total quadriceps muscle volume is equal or more than 7% deficit on involved leg compared with uninvolved leg, sporting injury with a Tegner score of 7+, and both knees without a history of injury/prior surgery will be recruited. To estimate the improvement of patients, isokinetic muscle assessment, ultrasound imaging and MRI for quadriceps muscle thickness, self-reported outcomes with questionnaires, KT-1000 for knee laxity and biomechanical analysis, and Xtreme CT for bone mineral density will be performed. To investigate the mechanism of PEMF therapy on increasing quadriceps strength, samples of blood serum will be drawn before and after intervention.DiscussionThis is the first trial evaluating the effects of PEMF on quadriceps muscle recovery after ACLR. The proposed study addresses a huge research gap by evaluating practical use of PEMF as part of rehabilitation. The proposed study will provide much needed scientific support in the use of this noninvasive treatment modality to facilitate recovery of quadriceps strength after PEMF.Trial registrationClinicalTrials.gov NCT05184023. Registered on 5 January 2022

Sarcopenia in knee osteoarthritis: the association with clinical and sonographic findings, physical function, and nutrition.

The purposes of this study were to examine to (1) the relation between OA and sarcopenia and to identify the most practical, easily accessible, and inexpensive method for investigating sarcopenia; (2) evaluation of sarcopenia risk factors in patients with OA. One hundred two patients with clinical and radiological diagnosis of knee osteoarthritis and 33 healthy control subjects were included in the study and all subjects were evaluated for sarcopenia. Dual-X-ray absorptiometry (DEXA) is used to measure body composition parameters and muscle thickness measurements with ultrasonography for diagnosis of sarcopenia. The mean age of the group with sarcopenia was statistically higher than the other two groups (p < 0.001). The weight, body mass index (BMI), waist circumference, upper-mid-arm circumference, thigh, and leg circumference of osteoarthritis (OA) patients with sarcopenia were statistically lower than those of non-sarcopenic and control group (p < 0.01, p < 0.001). Body composition parameter results showed that sarcopenic patients had statistically lower values as fat mass, lean body mass, and skeletal muscle index (p < 0.001, p = 0.001, p < 0.001, respectively) than those of non-sarcopenic and control group and fat mass index values (p = 0.012) are lower than the non-sarcopenic group. With respect to sarcopenia, the effect of adiponectin and leptin levels were not detected. It was determined that body composition values measured with DEXA, ultrasonographic measures, isokinetic muscle strength assessment, handgrip strength, and gait speed had predictive values for sarcopenia. We found that patients with sarcopenic OA were older, weaker, undernourished, and restricted in their level of physical activity in the study. Among the methods of determining sarcopenia, ultrasound becomes prominent with its practical, cheap, and easily accessible features. We think that our results will increase the awareness of the presence of sarcopenia in OA patients.