Isokinetic Variables Research Articles

Changes in isokinetic trunk muscle strength and endurance after two different restoration programs in people with chronic low back pain: A longitudinal retrospective study

BackgroundMultidisciplinary functional restoration programs (FRPs) aim to improve pain and function in people with chronic low back pain (CLBP). The intensity and content of FRPs varies; the benefits of one program over another are unclear. ObjectiveTo assess changes in trunk muscle strength and endurance after an intensive (IFRP) (for people on sick leave for >6 months with high levels of fear-avoidance beliefs about physical activity and work) or semi-intensive (SIFRP) (for people working) FRP in people with CLBP. MethodsLongitudinal retrospective study from March 2016 to December 2019. Setting: rehabilitation department of a tertiary care center. Trunk flexor and extensor muscle strength (60°.s−1) and endurance (120°.s−1) were measured with the Humac NORM isokinetic dynamometer at pre and post FRP. Change in isokinetic variables (peak torque, total work and flexor/extensor ratio) after each program was assessed with a paired t-test (p < 0.05). Pearson's rho and multiple linear regression assessed associations between changes in isokinetic and clinical variables and demographic characteristics. Results125 individuals, 63.2 % female, age 43.5 (10.3) years, were included. Mean low back pain intensity was 49.8 (24.9) and 37.2 (25.8)/100 and mean activity limitation (QBPDS) was 38.8 (16.4) and 32.0 (14.6)/100 in the IFRP and SFRP groups, respectively. Trunk extensor peak torque, flexor total work, extensor total work and flexor/extensor peak ratio improved significantly in both FRPs, p < 0.001. The flexor/extensor total work ratio improved in the IFRP group only, p = 0.003. Trunk extensor endurance increased more in the IFRP than the SIFRP group, the absolute pre-post differences for extensor total work [95%CI] N.m were 611.7 [495.2; 728.3] in the IFRP group and 380.0 [300.8; 459.3] in the SIFRP group. No variables were correlated and none predicted improvement in extensor total work in either group. ConclusionThis study highlights the short-term independence of clinical and trunk muscle strength and endurance changes.

A hop testing alternative for functional performance following anterior cruciate ligament reconstruction.

The purpose of this work was to provide a simple method to determine reactive strength during the 6-meter timed hop test (6mTH) and evaluate its association with isokinetic peak torque in patients following anterior cruciate ligament reconstruction (ACLR). Twenty-nine ACLR patients who were at least four months from surgery were included in this analysis. Participants were brought into the laboratory on one occasion to complete functional testing. Quadriceps and hamstring isokinetic testing was completed bilaterally at 60, 180, and 300 deg∙s-1, using extension peak torque from each speed as the outcome measure. The 6mTH was completed bilaterally using a marker-based motion capture system, and reactive strength ratio (RSR) was calculated from the vertical velocity of the pelvis during the test. An adjustment in RSR was made using the velocity of the 6mTH test to account for different strategies employed across participants. Repeated measures correlations were used to determine associations among isokinetic and hop testing variables. A two-way mixed analysis of variance was used to determine differences in isokinetic and hop testing variables between operated and non-operated legs and across male and female participants. Moderate positive associations were found between RSR (and adjusted RSR) and isokinetic peak torque at all speeds (r = .527 to .577). Mean comparisons showed significant main effects for leg and sex. Patients showed significant deficits in their operated versus non-operated legs in all isokinetic and hop testing variables, yet only isokinetic peak torque and timed hop time showed significant differences across male and female groups. Preliminary results are promising but further development is needed to validate other accessible technologies available to calculate reactive strength during functional testing after ACLR. Pending these developments, the effects of movement strategies, demographics, and levels of participation on RSR can then be explored to translate this simple method to clinical environments.

Hip Stability Isometric Test (HipSIT): Concurrent Validity and Reference Values for CrossFit® Participants.

The Hip Stability Isometric Test (HipSIT) is a practical clinical assessment of posterolateral hip muscle performance. There is no information regarding the validity of the HipSIT in participants exposed to high-intensity training, such as CrossFit®. The purpose of this study was to investigate the Hip Stability Isometric Test (HipSIT) concurrent validity with the isokinetic assessment in CrossFit® participants. A secondary purpose was to characterize posterolateral hip muscular performance with HipSIT according to sex and lower limb dominance in athletes who participate in CrossFit®. Cross-sectional. One-hundred and eleven CrossFit® participants were evaluated. The posterolateral hip muscles were evaluated using the HipSIT with a hand-held dynamometer. The hip extensors and abductors' peak torque and maximum work were assessed with the Biodex System® 4 Pro isokinetic dynamometer at 60º/s. Concurrent validity between measurements was assessed with the Spearman correlation coefficient and Bland-Altman analyses. The comparison of results between sexes and between limbs was also performed. Spearman analyses indicated a significant positive correlation with medium effect size between HipSIT and isokinetic variables ( = 0.36 to 0.49). Bland-Altman analyses showed that most measures were within the 95% limits of agreement. The HipSIT was greater in males than females (p < 0.001) and greater in the dominant than non-dominant limb (p = 0.03). The findings support using HipSIT in the clinical assessment of CrossFit® participants. Clinicians can use the data as reference values for athletes who participate in CrossFit® and should consider the difference between sexes and lower limbs. 3.

Upper Limb Strength and Performance Deficits after Glenohumeral-Joint-Stabilisation Surgery in Contact and Collision Athletes.

The primary aim was to identify and quantify differences in interlimb asymmetry magnitudes across a battery of upper extremity strength and performance tests at four and six months after glenohumeral-joint-stabilisation surgery shoulder stabilisation in contact and collision athletes compared to an un-injured group. A secondary aim was to investigate if identified asymmetry magnitudes changed from four months to six months post glenohumeral-joint-stabilisation. The third aim was to explore associations within the different performance and strength variables. Fifty-six male contact and collision sport athletes who had had undergone unilateral glenohumeral-joint-stabilisation were tested at 4 and 6 months post-surgery. An un-injured control group (n = 39 for upper extremity performance tests, n = 47 for isokinetic dynamometry) were tested on a single occasion. Three upper extremity force platform-based performance tests and angle-specific concentric internal and external isokinetic shoulder rotational strength were assessed, and inter-limb asymmetries were compared between the two groups. At four months post-surgery, the glenohumeral-joint-stabilisation group demonstrated significantly higher absolute interlimb asymmetry values than the un-injured group for almost all the performance test variables. In the ballistic upper-body performance tests, the glenohumeral-joint-stabilisation group achieved only half the body elevation reached by the un-injured (counter-movement push-up jump height (η2 = 0.50) and press-jump jump height (η2 = 0.39)). At 6 months post-surgery absolute inter-limb asymmetries reduced for the performance tests variables but some asymmetry persisted. The glenohumeral-joint-stabilisation group had significantly greater absolute inter-limb asymmetries for five out of the eight isokinetic variables. Contact and collision athletes who may be cleared to return to sport at four to six months after glenohumeral-joint-stabilisation surgery shoulder stabilisation continue to demonstrate upper limb strength and performance deficits when compared to their un-injured limb and to their un-injured counterparts.

Kinesio Taping Versus Athletic Taping in Managing Chronic Golfer’s Elbow in Male Athletes

Medial epicondylalgia is a repetitive stress condition. The aim of this study was to assess whether Kinesio taping offers any superiority over athletic taping for chronic medial epicondylalgia management. The results show statistically significant differences in isokinetic and patient self-reported variables between each group: (a) Group A: Kinesio tape with rehabilitation; (b) Group B: athletic taping with rehabilitation; and (c) group C: only rehabilitation. Although no significant differences in preintervention group assessments (p &gt; .05) were found, only Group (A) showed statistically significant posttreatment improvements. Kinesio taping over athletic taping appears effective for treating chronic medial epicondylalgia and facilitating pain reduction and isokinetic improvements.

The Associations Between Quadriceps Tendon Graft Thickness and Isokinetic Performance

Background: Anterior cruciate ligament reconstruction (ACLR) using the quadriceps tendon is an increasingly popular technique. Both partial-thickness quadriceps tendon (PT-Q) and full-thickness quadriceps tendon (FT-Q) graft depths are employed. Hypothesis/Purpose: This study was designed to assess isokinetic peak torque, average power, and total work during knee extension in patients with FT-Q or PT-Q grafts for ACLR. We hypothesized that both groups would show lower isokinetic values for the operated side, with greater deficits in the FT-Q group than in the PT-Q group. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 26 patients who underwent ACLR with either an FT-Q or PT-Q graft were recruited between June 2021 and November 2021. Patients underwent isokinetic knee extension testing at > 1 year after surgery. Mixed repeated-measures analysis of covariance with least square difference post hoc testing was used to determine significant differences or interactions for all variables. Results: Peak torque was significantly lower for the operated limb than the nonoperated limb in the FT-Q group (mean difference [MD] ± standard error [SE], −38.6 ± 8.3 Nċm [95% CI, −55.7 to −21.5 Nċm]; P < .001; d = 0.90) but not in the PT-Q group (MD ± SE, −7.3 ± 7.7 Nċm [95% CI, −23.2 to 8.5 Nċm]; P = .348; d = 0.20). Similarly, average power for the operated limb was lower than that for the nonoperated limb in the FT-Q group (MD ± SE, −53.6 ± 13.4 W [95% CI, −81.3 to −26.9 W]; P < .001; d = 0.88) but not in the PT-Q group (MD ± SE, –4.1 ± 12.4 W [95% CI, −29.8 to 21.5 W]; P = .742; d = 0.07), and total work was lower for the operated limb compared with the nonoperated limb in the FT-Q group (MD ± SE, −118.2 ± 27.1 J [95% CI, −174.3 to −62.2 J]; P < .001; d = 0.96) but not in the PT-Q group (MD ± SE, −18.3 ± 25.1 J [95% CI, −70.2 to 33.6 J]; P = .472; d = 0.15). Conclusion: The FT-Q group showed significant deficits in the operated limb compared with the nonoperated limb for all isokinetic variables. In contrast, no significant differences were found between the nonoperated and operated limbs for the PT-Q group.

Are Previous Joint Injuries Associated with Muscle Performance in Volleyball Athletes?

Objective The aim of the present study is to determine whether previous shoulder and knee injuries were associated with isokinetic fatigue index and agonist/antagonist ratio of shoulder internal/external rotators and knee flexors/extensors in male volleyball athletes. Methods The current study is a cross-sectional investigation of 49 male elite volleyball players competing at a high level in Brazil. Isokinetic fatigue index and agonist/antagonist profiles were assessed during the preseason. Additionally, in order to record previous injuries, the athletes answered a standardized questionnaire. We conducted a receiver operating characteristic (ROC) curve analysis to determine the association strength and the clinically relevant cut-off point for variables presenting statistical significance for the area under the curve (AUC) (α = 0.05). An independent t-test was used to compare isokinetic variables between athletes with and without previous injury (α = 0.05). Results The results of the ROC curve analysis indicated that hamstring fatigue index values at 300 o /s were associated with the presence of previous knee injury (area under the curve [AUC] = 73%, p = 0.004), and shoulder external rotators fatigue index values at 360°/s were not associated with the presence of previous shoulder injury (AUC = 68%, p = 0.053). Conclusions Elite volleyball athletes who reported previous knee injuries were prone to a higher fatigue index than those reporting no injuries. Knee flexor resistance training might be useful for those athletes who reported knee injuries in the previous season.

Effectiveness of a Cucumber Extract Supplement on Articular Pain in Patients with Knee Osteoarthritis: A Randomized Double-Blind Controlled Clinical Trial

This 8-week randomized double-blind placebo-controlled study aimed to assess the effectiveness of supplementation with an extract of Cucumis sativus L. (20 mg/day) on pain and other variables in patients with knee osteoarthritis (OA) over 40 years. The change in pain intensity using a 1–10 cm visual analog scale (VAS) was the primary endpoint. Fifty-five patients (mean age 50.6 ± 8.6 years) were included (experimental group, n = 29; placebo, n = 26). VAS scores for pain decreased significantly in both study groups, but decreases were higher in the experimental group (between-group p = 0.013). Improvements in pain, stiffness, and physical function according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were also significantly higher in the experimental group. The Timed Up and Go test result also decreased significantly in the experimental group. An improvement in muscle function was associated with significant increases in isokinetic and isometric dynamometry variables, particularly for isometric 60°·s−1 and 180°·s−1 knee flexion exercises in the experimental group. Plasma levels of interleukin-1-beta (IL-1β) and matrix metalloproteinase-3 (MMP-3) also decreased significantly in the experimental group. Based on the beneficial effects of cucumber on symptomatology and inflammatory and cartilage degradation biomarkers in knee OA, cucumber extract supplementation may a useful natural approach to maintain healthy joints.

RELATIONSHIP BETWEEN ISOKINETIC STRENGTH, VERTICAL JUMP, SPRINT SPEED, AGILITY AND YO-YO INTERMITTENT RECOVERY TEST PERFORMANCE IN SOCCER PLAYERS

The current study investigated the relationship between isokinetic knee strength, jump performance, agility, linear and repeated sprinting capacity and Yo-Yo IR1 test performance and the fatigue indices of some of these variables in semi-professional soccer players. Twenty semi-professional soccer players participated in this study, performing 6 tests: bilateral concentric isokinetic strength tests of the knee extensors and flexors (60◦.s-1 and 300◦.s-1), jump tests (countermovement, squat and repeated jumping), linear sprints (10 and 30 m), agility (Illinois test), Bangsbo repeated sprints (7 x 34.2 m), and Yo-Yo IR1 tests. While no isokinetic variables were significantly correlated with field test results, some jump test results correlated with AgiWB, 10- and 30-m sprint times, RSTMEAN and FIRS. Furthermore, the knee isokinetic strength (60◦.s-1 and 300◦.s-1) indices and jump capacities demonstrated moderate to strong relationships with each other. In addition, AgiWB correlated with the 10-m sprint times and RSTMEAN, 30-m linear sprint times correlated with 10-m sprint times and AgiWB, and FIRS and RSTMEAN correlated with the Yo-Yo IR1 test results. The results suggest that power output during CMJ and RJ tests and not isokinetic knee strength are informative in determining field conditioning parameters for semi-professional soccer players.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0587/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

Angle-Specific Isokinetic Shoulder Rotational Strength Can be Reliably Assessed in Collision and Contact Athletes.

An increased understanding of rotational strength as a potential prognostic factor for injury in contact and collision athletes may be important in planning return to sport. The aim of this study was to (1)determine the test-retest reliability of clinically relevant, angle-specific rotational and peak torque measurements in a cohort of uninjured collision and contact athletes; (2)develop a normal descriptive profile of angle-specific rotational torque measurements in the same cohort; and (3)examine the effects of direction and joint angle on shoulder rotational strength interlimb asymmetries. Twenty-three collision and contact athletes were recruited for the interday reliability substudy and 47 athletes were recruited for the remaining substudies. We used intraclass correlation coefficients with 95% confidence intervals to quantify interday reliability of all variables. We used a 2-way repeated-measures analysis of variance to analyze differences in absolute interlimb asymmetries. Interday reliability for the isokinetic strength variables was good to excellent (0.78-0.90) on the dominant side and moderate to good (0.63-0.86) on the nondominant side. Maximum angle-specific torque (as well as peak torque) can be measured reliably in internally and externally rotated positions. A normal profile of clinically relevant, angle-specific shoulder rotational torque measurements for collision and contact athletes has been established which provides a reference when assessing shoulder strength in this population.

Clinical shoulder measurements related to joint loads in collegiate pitchers

Pitchers are prone to upper extremity injury due to repetitive high joint loads. Clinical measures of shoulder strength and range of motion (ROM) have shown links to injury risk in pitchers, however, these factors have rarely been studied in relation to throwing joint loads. The purpose of this study was to identify which clinical ROM and isokinetic strength variables were related to peak shoulder and elbow joint torques in collegiate pitchers. Thirty-three healthy collegiate pitchers participated in this study. Fastball velocity, shoulder concentric and eccentric strength, and passive shoulder ROM variables were analyzed using a Lasso regression to determine what factors influenced shoulder internal rotation torque and elbow varus torque. Fastball velocity was selected by the Lasso as indicator of increased shoulder and elbow torque. Passive shoulder external rotation ROM was also selected as an important factor in joint loading with increased shoulder external rotation ROM being related to lower joint loads. The bilateral ratio of shoulder internal rotator concentric strength was related to peak shoulder and elbow torques with an increase in the bilateral ratio of shoulder strength leading to reduced joint torques. Increases in the eccentric external rotator to concentric internal rotator strength (functional ratio) of the dominant arm and increases in dominant arm eccentric internal rotator strength were both related to increases in each joint torque. Results from the study indicate that pitch speed, passive shoulder external rotation ROM, and the isokinetic shoulder strength profile including internal rotator strength and functional strength ratio of pitchers are related to joint loading during the pitch and may be important to monitor in relation to injury risk and/or during rehabilitation. These results provide insight into the role that both shoulder ROM and rotator cuff strength play in the dynamic stabilization of the elbow and shoulder during pitching.

Association between Concentric and Eccentric Isokinetic Torque and Unilateral Countermovement Jump Variables in Professional Soccer Players.

Isokinetic tests have been highly valuable to athletic analysis, but their cost and technical operation turn them inaccessible. The purpose of this study was to verify the correlation between unilateral countermovement jump variables and isokinetic data. Thirty-two male professional soccer players were subjected to the isokinetic testing of both knee extensors and flexors in concentric and eccentric muscle contractions. They also executed unilateral countermovement vertical jumps (UCMJ) to compare maximum height, ground reaction force, and impulse power with isokinetic peak torque. Data analysis was conducted through Pearson correlation and linear regression. A high correlation was found between dominant unilateral extensor concentric peak torque and the UCMJ maximum height of the dominant leg. The non-dominant leg jump showed a moderate correlation. No other variable showed statistical significance. Linear regression allowed the generation of two formulae to estimate the peak torque from UCMJ for dominant and non-dominant legs. Although few studies were found to compare our results, leading to more studies being needed, a better understanding of the unilateral countermovement jump may be used in the future as a substitute to the expensive and technically demanding isokinetic testing when it is unavailable, allowing the assessment of lower limb physical asymmetries in athletic or rehabilitation environments.

Specificity of isokinetic assessment in noncontact knee injury prevention screening: A novel assessment procedure with relationships between variables in amateur adult agility-sport athletes

ObjectivesTo present a new knee isokinetic assessment procedure linked to noncontact knee injury mechanisms and examine correlations between variables relevant to noncontact knee injury prevention screening (peak torque [PT, Nm], time-to-peak torque [TTPT, ms], angle-of-peak torque [APT, °], mean PT [MPT, Nm]). DesignCross-sectional. SettingSports medicine laboratory. ParticipantsThirty-four agility-sport athletes (male/female n = 18/16, age 24.1 ± 3.5yr, height 171.8 ± 9.6 cm, mass 70.6 ± 12 kg). Main outcome measuresPearson's/Spearman's correlation (r/rs), coefficient of determination (r2/rs2). ResultsMost correlations were statistically non-significant or statistically-significant with only weak-to-moderate coefficients. For both knee extension and flexion, PT and MPT were significantly and strongly correlated (r = 0.99, r2 = 0.98, p = 0.001). Graphical analyses revealed two datapoint clusters for knee flexion TTPT and APT. One cluster indicated some participants could generate knee flexor PT rapidly (<150 ms) at low knee flexion angles (<45°) and the other cluster indicated that other participants could not (>200 ms, >50°). ConclusionsIn this study, most isokinetic variables represented distinct knee neuromuscular characteristics. For both knee extension and flexion, only PT or MPT need be used to represent isokinetic maximal strength. Knee flexion TTPT and APT may have utility in noncontact knee injury prevention screening with amateur adult agility-sport athletes.

Bilateral Differences in Anthropometric Measurements and Isokinetic Strength Variables of Female University Netball Players

The unilateral demands on the dominant (D) limbs in netball players, may lead to developments and changes that differs from that of the non-dominant (ND) limbs. An individual who is constantly exposed to unilateral movements or repeated use of the D limb, can also develop bilateral differences between the D and ND limbs. The purpose of the study was to determine if any significant bilateral differences in anthropometric and isokinetic strength measurements occurred between the D and ND limbs of the upper and lower parts of the body in female university netball players.

Bilateral Differences in Anthropometric Measurements and Isokinetic Strength Variables of Female University Netball Players

The unilateral demands on the dominant (D) limbs in netball players, may lead to developments and changes that differs from that of the non-dominant (ND) limbs. An individual who is constantly exposed to unilateral movements or repeated use of the D limb, can also develop bilateral differences between the D and ND limbs. The purpose of the study was to determine if any significant bilateral differences in anthropometric and isokinetic strength measurements occurred between the D and ND limbs of the upper and lower parts of the body in female university netball players.

Acute effect of different duration times of application of myofascial release on quadriceps femoris strength: A randomized clinical trial

ObjectivesTo evaluate the effect of Miofascial Release (MFR) on knee extensors strength, at different duration times of application. Method51 healthy individuals were randomly assigned to one of three groups (3min, 5min or placebo) in this randomized clinical trial. The knee extensors strength was assessed in two conditions: pre and post-intervention, using an isokinetic dynamometer, at speeds of 60° and 120°/s. MFR was applied on the anterior surface of the thigh for 3min or 5 min, according to the experimental groups. The placebo group underwent through the application of a non-therapeutic gel, associated with 3min of a light touch on the skin. Peak torque, total work and mean power were the isokinetic variables analyzed through a multivariate analysis of variance (MANOVA) with p ≤ 0.05. ResultsOur findings suggest a main effect and interaction between moments (pre and post-intervention) and speeds (60° and 120°/s) for total work and mean power (p < 0.01). Likewise, main effect and interaction of speed were observed for peak torque (p < 0.01). There were no significant differences for the other analyzed variables. ConclusionNo significant main effect of MFR were detected in any of the proposed application time on peak torque, total work and mean power, in the knee extensors, compared to the placebo group.

Impaired muscle capacity of the hip and knee in individuals with isolated patellofemoral osteoarthritis: a cross-sectional study.

Aims:The aims of this study were to compare the capacity of the knee and hip muscles between individuals with and without isolated patellofemoral osteoarthritis (PFOA) and to evaluate the impact of PFOA on pain, stiffness, and physical function.Methods:This cross-sectional study evaluated muscle capacity of the hip and knee using an isokinetic dynamometer. The isokinetic variables used in the statistical analysis were peak torque, total work, and average power. Pain, stiffness, and physical function were assessed using questionnaires.Results:A total of 26 individuals participated in the study (13 with PFOA and 13 controls). The PFOA group exhibited lower peak torque, total work, and average power for knee extension and flexion in the concentric mode (p ⩽ 0.01) as well as lower peak torque and total work for knee extension (p ⩽ 0.005) and lower total work for knee flexion (p = 0.05) in the eccentric mode. The PFOA group exhibited lower peak torque of the extensor, abductor, adductor, and internal rotator muscles of the hip (p ⩽ 0.05), less total work of the abductor and adductor muscles (p ⩽ 0.04), and lower average power of eccentric adduction of the hip (p = 0.01) compared with the healthy controls. Compared with the control group, the PFOA group had a higher level of pain, stiffness, and compromised physical functioning self-reported (p ⩽ 0.005).Conclusion:Participants with PFOA exhibited impairments regarding muscle capacity of the hip and knee, higher level of pain and stiffness as well as compromised physical functioning in comparison with healthy controls.

Association between the handgrip strength and the isokinetic muscle function of the elbow and the knee in asymptomatic adults.

Background:The handgrip strength is a practical, valid, reliable, low-cost tool that presents strong correlations with several health conditions. However, handgrip strength may be inaccurate to prospectively predict the variability of muscular function since the decrease in muscular strength over the years varies according to a muscular group or between upper and lower limbs. Our hypothesis is that the handgrip strength cannot explain the variance of muscle function prospectively.Purpose:The aim of this study was to evaluate the cross-sectional and prospective association between handgrip strength and isokinetic muscle function of the knee and elbow in 780 asymptomatic adults.Methods:In a sample of 780 adults, we obtained handgrip strength and elbow and knee muscle function (for both flexion and extension at 60°/s and 300°/s) using, respectively, a hydraulic dynamometer and an isokinetic dynamometer. In a cross-sectional analysis, we analyzed the data obtained from baseline assessment. Then, we calculated the absolute change as a result of the variation data between the baseline and the 1-year follow-up assessment of each participant. The correlations were analyzed using Pearson or Spearman coefficients. We used multivariate models to investigate the association between handgrip strength and isokinetic muscle function.Results and Discussion:The cross-sectional correlations were significantly moderate-to-strong (r = 0.41–0.71, p < 0.01), but became weak-to-moderate (r = 0.26–0.34, p < 0.01) prospectively. In the cross-sectional analysis, the handgrip strength was selected as a strong predictor for isokinetic variables (∆R2 = 0.171–0.583, p < 0.05) as expected. Although handgrip strength was also selected as a significant predictor in prospective analysis, it explained only a little variance in isokinetic muscle function of the knee (∆R2 = 0.7–0.117, p < 0.05). Regarding the predictive models for the elbow, handgrip strength was not selected prospectively.Conclusion:The 1-year absolute change of the handgrip strength cannot explain the variance of the isokinetic muscle function. Thus, specific measures are required for assessing muscle function in epidemiological studies.

High Levels of Physical Activity May Promote a Reduction in Bone Mineral Density in Peritoneal Dialysis.

Background and objectives: Peritoneal dialysis (PD) patients are expected to present lower levels of physical activity, unhealthy changes at the body composition level, and low levels of strength. Firstly, this study aimed to report the sex differences in physical activity, body composition and muscle strength and the relations among these variables. Secondly, we analyze the relationship between physical activity and biochemical parameters. Materials and Methods: Thirty-four patients (13 women and 21 men) participated in this study. Body composition was assessed by bioimpedance and dual-energy X-ray absorptiometry (DXA), and maximum isokinetic unilateral strength, analytical parameters and physical activity levels were evaluated. Results: The men showed higher values for weight, height, lean body mass, bone mineral content, bone mineral density (BMD) and total body water, while women showed higher values for the percentage of fat mass and hydration of lean body mass (p < 0.05). No differences between the sexes were found in different levels of physical activity; however, males registered significantly higher values for isokinetic strength variables except for knee extensor strength. BMD was positively related to sedentary activity and negatively related to moderate and vigorous activity (r = 0.383 and r = −0.404, respectively). Light physical activity was negatively correlated with albumin (r = −0.393) and total protein (r = −0.410) levels, while moderate/vigorous activity was positively correlated with urea distribution volume (r = 0.446) and creatinine clearance (r = 0.359) and negatively correlated with the triglyceride level (r = −0.455). Conclusions: PD patients with higher levels of physical activity present better results in terms of body composition and biochemical parameters. Additional studies should be conducted to clarify the relation between physical activity level and BMD.

Acute application of photobiomodulation does not bring important gains for the muscular performance and functionality of diabetic individuals.

Photobiomodulation therapy (PBMT) has been used to improve the physical performance of individuals with advanced age; however, there are no studies in the literature that support the application of light-emitting diode (LED) therapy for the muscular performance of individuals with diabetes mellitus who show a decline in functionality. The aim of the study was to analyze the acute effects of PBMT on strength and functional performance in type 2 diabetic individuals. Sixty-three volunteers were recruited and randomized into five groups: control (C), sham (S), red LED (R), infrared LED (IR), and red LED + infrared LED (R + IR). On the first day, the volunteers were evaluated using the time up and go (TUG), the 6-min walk test (6MWT), and isokinetic dynamometer of the ankle. In the following 3days, groups R, IR, R + IR, and S returned for application of PBMT bilaterally, with 180J of energy on each leg. On the fifth day, a reassessment was performed. There was no statistical difference between groups for the variables of the isokinetic dynamometer, TUG, and 6MWT. Analysis of the size of the clinical effect for the isokinetic variables showed that there was no pattern among the effects observed. There is a moderate effect in favor of R, IR, and R + IR in relation to C for the TUG and a moderate effect of R + IR in relation to C for the 6MWT. The PBMT applied for a short period does not bring important gains for the muscular performance and functionality of diabetic individuals.