Search Results

Context: To assess the reliability of a remote 2D markerless motion tracking method (Kinovea) to quantify knee and hip angles during dynamic tasks. Methods: Fourteen healthy adults performed body weight squats and lateral lunges while video recording themselves at home. Knee and hip angles were quantified in the sagittal plane for the squats and in the frontal plane for the lateral lunges. Two students each performed the video analysis procedure twice, 2 weeks apart. Intraclass correlation coefficients were used to calculate the intrarater and interrater reliability for angles at maximum depth. The intrarater and interrater agreement over the joint angle–time signals were quantified using a validation metric; an acceptable agreement threshold was set at a validation metric of 0.803 or higher. Standard error of measurement (SEM) was also calculated. Results: Reliability was good to excellent (intraclass correlation coefficients = .80–.98) for all angle comparisons at maximum depth. The agreement over the entire joint angle–time signal was acceptable for all squat variables except for the interrater hip angle comparison (validation metric = 0.797). None of the lateral lunge variables met the threshold of acceptable agreement. The mean SEM across participants for all joint angle–time signal and for maximum depth was acceptable (<5°) for all measurements (SEM = 1.2°–4.9°). Conclusions: Overall, the reliability, agreement, and SEM quantified in this study support the integration of remote methods to quantify lower-extremity kinematics into research and clinical practice.

Context: Hip muscle imbalance, especially between gluteal muscles and tensor fasciae latae (TFL), is one of the risk factors for developing low back pain which should be considered in rehabilitation programs. This study compared the effect of exercises with gluteal-to-TFL muscle activation index above and below 50 on pain intensity, disability, and lower limbs’ range of motion (ROM) in patients with nonspecific chronic low back pain. Design: A semiexperimental intervention study with a pretest and posttest. Methods: A total of 45 patients with nonspecific chronic low back pain were randomly divided into 2 experimental groups of gluteal-to-TFL muscle activation index above 50 (n = 15), below 50 (n = 15), and a control group (n = 15). Pain intensity (visual analog scale), disability (Roland–Morris Disability Questionnaire), and lower limbs’ ROM including hip extension, hip abduction, hip external rotation, and knee extension (goniometer) were assessed at pretest and after 8 weeks of intervention. Results: Within-group comparison showed significant improvement of pain, disability, and ROMs in both experimental groups. No significant changes were observed in the control group. In between-group analysis, significant differences were observed in group of gluteal-to-TFL muscle activation index above 50 for only pain (P = .03) and disability (P = .01). For ROMs, although clinical improvement of lower limbs’ ROMs was higher in group of gluteal-to-TFL muscle activation index above 50, no statistically significant differences were found between 2 experimental groups. Both experimental groups were superior to the control group for all outcomes. Conclusions: Findings indicate the statistically and clinically superior effectiveness of exercises with a gluteal-to-TFL muscle activation index above 50 in the reduction of pain and disability. Based on the clinical significance of exercises with a gluteal-to-TFL muscle activation index above 50 for improving ROMs, utilizing specific exercises that more activated gluteal muscle compared to TFL is recommended for patient with restricted lower limbs’ ROMs.

Context: Current devices to assess strength performance in handball may not be sufficiently sports-specific and reliable methods. Functional electromechanical dynamometry is a new technology that allows the development of accurate strength tests in athletes. Purpose: To determine the absolute and relative reliability and to compare the reliability of the right and left side, and mean and peak force of 3 specific strength tests in handball players with a functional electromechanical dynamometer: unilateral pullover, standing lift, and step forward. Methods: Fourteen male handball players of the first Spanish division (28.79 [4.81] y; 10.38 [4.63] y of professional experience) performed a repeated-measurement design. Three testing sessions were performed (one per week). The first measurement consisted of 4 isometric tests (right and left unilateral pullover, and right and left standing lift) to obtain isometric peak force, and in the second and third sessions, 6 incremental tests until failure (right and left unilateral pullover, and right and left standing lift, right and left step forward) were performed. Results: The tests provided high reliability or acceptable reliability for mean and peak strength of unilateral pullover, standing lift and step forward (intraclass correlation coefficient = .83–.97; coefficient of variation = 3.90–11.57). Effect side was negligible in any of the parameters, except for a small effect side in the left peak force for unilateral pullover and a small effect side on the left side for a step forward. Significant differences in reliability (coefficient of variation ratio > 1.15) were found between the right and left sides and peak and mean force in all exercises except peak force in unilateral pullover and step forward. Conclusion: These results confirm that the tests could be applied to assess physical performance in handball at the same time as regular gym training. Moreover, this is an excellent opportunity to individualize the player’s weekly load.

Context: Decreased muscle strength and balance in patients with functional ankle instability (FAI) can be effectively improved by ankle strength training. Low-load blood flow restriction (LL-BFR) training increases muscle size and strength, but there is limited evidence from studies on muscle strength and balance in FAI patients. Objective: To study the effects of LL-BFR training versus high-load training (HLT) on muscle strength and balance in FAI patients. Design: Randomized controlled trial. Participants: Forty-six young adults with a history of FAI. Interventions: Participants in the LL-BFR and HLT groups performed 4 sets (30 × 15 × 15 × 15) of ankle training at 20% to 40% of the one-repetition maximum and 70% to 85% one-repetition maximum, respectively, twice a week for 6 weeks. Main Outcome Measure(s): Plantar flexion, dorsiflexion, inversion, and eversion muscle strength, and the Y-balance test scores were assessed at baseline and after 3 and 6 weeks; the thickness of the tibialis anterior, triceps surae, and peroneus longus muscles were assessed at baseline and after 6 weeks. Results: Inversion, eversion, dorsiflexion, and plantar flexion muscle strength; tibialis anterior, triceps surae, and peroneus longus thickness; and Y-balance test scores were significantly increased in the LL-BFR group after 3 and 6 weeks compared with baseline (P < .05), with no significant difference between the LL-BFR and HLT groups after 6 weeks (P > .05). However, at the end of 3 weeks, eversion muscle strength and Y-balance test scores were significantly higher in the LL-BFR group than in the HLT group (P < .05). Conclusions: Over 6 weeks, LL-BFR training was as effective as HLT in improving ankle muscle strength, muscle thickness, and balance in FAI patients, but LL-BFR training improved the ankle eversion muscle strength and dynamic balance more than HLT did in the early stages of the intervention. This finding will provide a new intervention strategy for the clinical rehabilitation of FAI patients.

Context: The Y Balance Test (YBT) is a simple, reliable, cost-effective screening test. It is used to evaluate dynamic balance as well as to determine the potential risk of injury of the lower limbs. The reliability of YBT has been widely reported in the general population. However, there are no studies evaluating the reliability of YBT use in athletes with intellectual disability (ID). The aim of the study was to examine the reliability of the YBT in runners with ID. Design: A reliability study. Methods: Twelve male runners (short-distance running) with ID (age 25.1 [4.50] y, height 169.1 [4.2] cm, weight 69.5 [5.5] kg, and intelligence quotient 60.8 [2.4]). The YBT was used to measure participants’ dynamic balance in the anterior, posteromedial, and posterolateral reach directions. The analysis used the normalized values to the relative length of the lower limbs. A 1-way (trial) repeated-measures (5) analysis of variance for each direction was used. Intraclass correlation coefficient, standard error of measurement, and minimal detectable change were computed to assess the reliability of the YBT between trials. Results: After 6 practice trials, 3 out of 5 consecutive ones achieved results stabilization for all directions and both legs (P < .05). The intraclass correlation coefficient, standard error of measurement, and minimal detectable change values for all trials ranged from .76 to .87, 5% to <7%, and 11% to <15%, respectively. Conclusion : The YBT is a highly reliable tool to measure the dynamic balance of male runners with ID. Therefore, it is recommended to perform 6 practice trials and 3 measurements in these runners.