Hamstring Muscle Strength Research Articles

The effectiveness of vitamin D supplementation in patients with end-stage knee osteoarthritis: Study protocol for a double-blinded, randomized controlled trial.

Osteoarthritis (OA) knee is one of the most common chronic degenerative conditions that imposes clinical and economic burdens on individuals and societies worldwide. Previous studies showed vitamin D levels correlated positively with lean muscle mass and grip strength, implying that vitamin D supplementation may improve muscle health in knee OA subjects. This randomized controlled trial (RCT) aims to compare the effects of vitamin D supplementation on knee muscle strength, physical function, pain, and sarcopenia status in patients with end-stage knee OA. Patients and outcome assessors will be blinded to group allocation. Fifty-six end-stage knee OA patients with vitamin D insufficiency fulfilling our inclusion criteria will be invited to participate in this study. Patients will be randomly assigned to take vitamin D supplementation (4,000 IU capsule daily) or placebo for six months. Measurements will be taken at baseline, three and six-month after the commencement of the vitamin D supplement, and 6-month after the interventional period. The primary outcome includes the isometric quadriceps and hamstring muscle strength measured by a hand-held dynamometer. Secondary outcomes include pain, performance-based and self-reported physical function and sarcopenia status. The success of this study will provide scientific evidence of whether the relatively cheap and well-tolerated vitamin D supplement can improve quadriceps muscle strength, physical function, pain symptoms, and sarcopenia status of this increasingly large population for end-stage knee OA patients. The study has great clinical significance given Hong Kong's lengthy and growing waiting list for complete knee replacement procedures. Trial registration: The trial was registered on clinicaltrials.gov (NCT05981534) on 31st July 2023.

Comparison of quadriceps and hamstring muscle strength ratios between dominant and non-dominant legs in Saudi under-17 and under-19 premier league football players: A cross-sectional study

Football’s global popularity is often overshadowed by frequent lower limb injuries, particularly hamstring strains, which are linked to imbalances in the strength ratio of hamstring-to-quadriceps (H/Q). Research on these factors among Saudi Premier League players, specifically in Madinah City, is limited. Our study is a cross-sectional study that assessed 42 male professional football players from Ohoud Football Club, divided into Underage 17 (UD- 17) and Under age 19 (UD-19) of age groups. The Strength of muscle for hamstrings and quadriceps, as well as the H/Q ratio, was measured using handheld dynamometers (HDD), and demographic data were analyzed using SPSSv26. Results showed that UD-19 players had significantly greater quadriceps strength on both dominants (dominant and non-dominant) sides compared to UD-17 players, with no significant differences in strength of hamstring. The ratio of hamstring to quadriceps was significantly higher in UD-17 players on the dominant side compared to UD-19 players, but statistically significant differences were not found on the non-dominant side. These results suggest that quadriceps strength develops with age and training, potentially reducing injury risk, while the strength of hamstring stabilizes earlier. Tailored training programs focusing on quadriceps strength and balanced hamstring development are recommended for improving injury prevention and performance. Future research involving larger and more diverse samples could further validate these findings and provide a deeper understanding of muscle dynamics in young football players.

Tale of quadriceps and hamstring muscle strength after ACL reconstruction: a systematic review with longitudinal and multivariate meta-analysis

ObjectiveThis study aimed to investigate how knee extensor and flexor strength change over time after anterior cruciate ligament reconstruction (ACLR).DesignSystematic review with longitudinal meta-analysis.Data sourcesMedline, Embase, CINAHL, Scopus, Cochrane CENTRAL...

Y-Balance Test after ACL Reconstruction: the relationship with knee and hip muscle strength, ankle dorsiflexion range of motion and postural stability

BackgroundY-Balance Test (YBT) assesses postural stability. When is applied to patients after anterior cruciate ligament reconstruction (ACLR), it is not clear which variables influence its result. ObjectiveTo connect YBT and postural stability, quadriceps, hamstring, and gluteus complex muscle strength, ankle dorsiflexion range of motion (ADFROM). Study designCross-sectional. MethodsFifty-nine participants (52 males and 7 females) with ACLR ≥ 6 months were evaluated. YBT anterior, posterolateral, posteromedial, and composite, isokinetic peak torque of the knee, strength of the gluteal complex with Hip Stability Isometric Test, ADFROM with Weight-Bearing Lunge Test, postural stability with Stability Index of Biodex Balance System® were applied. ResultsIn the ACLR limb, the multivariate regression linear models pointed out an association between the quadriceps muscle strength and ADFRM with anterior, posteromedial and composite reaches (R2= .30; .23; .26). Hamstring muscle strength and ADFRM with posterolateral (R2=.13). In the uninjured limb, overall stability index and ADFRM with anterior reach (R2=.25), strength of gluteal complex with posteromedial (R2=.31), hamstring muscle strength, Overall and lateromedial stability indexes with posterolateral (R2= .20), hamstring muscle strength, Overall stability index, ADFRM and strength of gluteal complex with composite (R2=.32). ConclusionsThe quadriceps muscle strength and ADFRM are important variables for YBT performance in the ACLR limb. In the uninjured limb, ADFROM, the strength of the gluteal complex and hamstring, overall and lateromedial stability indexes are associated with YBT performance. We question the utility of the YBT to measure postural stability given the lack of association with other postural stability measures.

Understanding How Eccentric Hamstring Strength Affects Football Performance: The Scientific Secret To Fast Running

This study aimed to investigate the impact of eccentric hamstring strength, identified as a significant factor in the risk of hamstring injury, on maximum sprinting speed. Twenty-three football players competing in the Turkish Super League, with an average age of 25.12±3.22, were included in the study. The eccentric hamstring muscle strength of the athletes was measured using the N3 Nordic Hamstring Curl Exercise device. The maximum sprinting speeds of the players were determined by a GPS analyst. It was found that there was no significant relationship between eccentric hamstring strength on both dominant and non-dominant sides and maximum sprinting speed. Similarly, no significant relationship was found between the difference in eccentric hamstring strength between the two sides and maximum sprinting speed values (p>0.05). The study concluded that there is no association between eccentric hamstring muscle strength parameters and maximum sprinting speed in football players. As confirmed in this study, isolated maximum eccentric hamstring muscle strength alone does not appear to be the sole determinant parameter for horizontal force production during sprinting. However, further research is needed in this area.

Stair-Climbing Training with Interferential Electrotherapy Improves Knee Muscle Strength, Dynamic Postural Stability, Pain Score, and Physical Activity in Patients with Knee Osteoarthritis.

Background/Objective: This study aimed to compare the functional outcomes, such as knee muscle strength, dynamic postural stability, pain scores, and physical activity, in patients with knee osteoarthritis (OA) on stair climbing training with and without interferential electrotherapy (IFE) for 12 weeks. Methods: A total of 40 knee OA patients with Kellgren-Lawrence (K-L) grade ≤ 2 were enrolled (20 stair-climbing training with IFE vs. 20 stair-climbing training without IFE). The knee quadriceps and hamstring muscle strengths were measured using an isokinetic device. The dynamic postural stability was assessed using postural stabilometry. The pain score was evaluated using the visual analog scale (VAS). Physical activity was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: The WOMAC score was significantly different (p < 0.019) between stair-climbing training with and without IFE in patients with knee OA, while knee muscle strength, dynamic postural stability, or pain score were not (all p > 0.05). Conclusion: Stair-climbing training with IFE was more beneficial for physical activity recovery than stair-climbing training without IFE. Therefore, clinicians and therapists should be aware that stair climbing, which can be practiced in daily life for the management of patients with knee OA, and the addition of IFE may improve physical activity.

In the medium term, more than half of males report kinesiophobia after anterior cruciate ligament reconstruction

ObjectivesAnterior cruciate ligament rupture is a serious trauma with long-term consequences for the patient. Psychological and physiological factors may negatively affect patient recovery after anterior cruciate ligament reconstruction (ACLR), and development of kinesiophobia is possible. The aim of this study was to examine the presence of kinesiophobia and lower-leg muscle strength recovery in both sexes after ACLR. Methods140 ACLR patients agreed to participate in the study. Kinesiophobia was assessed using the Tampa Scale of Kinesiophobia (TSK). The Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS) and Tegner Activity Scale (TAS) were used for patient-related outcome measurements. In both legs quadriceps and hamstring muscle strength at 60°/s and 180°/s were measured with an isokinetic dynamometer. For dynamic balance and leg function, the Y-balance test and single-leg hop test were used. Results100 (71%) males and 40 (29%) females—mean age 32.5 (±8.3)—were examined 5.5 (±1.25) years after ACLR. 68/140 patients (48.6%) reported a TSK kinesiophobia score equal to or higher than 37 points: 54/100 (54%) males and 14/40 (35%) females (p ​= ​0.04). Patients with kinesiophobia had significantly lower KOOS values (p ​< ​0.001). In terms of the TAS no significant differences were found between those with or without kinesiophobia. Knee strength deficiency at 180°/sec and 60°/sec was significantly higher in the kinesiophobia group in knee extension in males (p ​= ​0.009) and knee flexion in females (p ​= ​0.001). Normalized body weight isokinetic average peak torque strength tests were significantly better in males compared to females in both groups (p ​< ​0.001). ConclusionBoth sexes reported high rates of kinesiophobia, but males are at higher risk of developing kinesiophobia than females in the medium term after ACLR. Furthermore, patients with kinesiophobia have significantly lower total KOOS scores, and females were significantly weaker than males in knee flexion and extension according to normalized body weight muscle strength tests. Also, a longer time from injury to surgery increases the risk of kinesiophobia in females. Level of evidenceLevel IV. Type of studyRetrospective case series study. Clinical trial registrationTrial registration in ClinicalTrials.gov. Identifier: NCT05762809.

Low-Load Resistance Exercise With Blood Flow Restriction Versus High-Load Resistance Exercise on Hamstring Muscle Adaptations in Recreationally Trained Men.

Kamiş, O, Gürses, VV, Şendur, HN, Altunsoy, M, Pekel, HA, Yıldırım, E, and Aydos, L. Low-load resistance exercise with blood flow restriction vs. high-load resistance exercise on hamstring muscle adaptations in recreationally trained men. J Strength Cond Res XX(X): 000-000, 2024-Low-load resistance exercise with blood flow restriction (BFR-RE) has been suggested as a viable alternative exercise for traditional high-load resistance exercise (HL-RE). However, very little is known about hamstring muscle thickness, stiffness, and strength after BFR-RE. This study aimed to compare the effects of 6 weeks of BFR-RE and HL-RE on hamstring muscle thickness, stiffness, and strength. Twenty-nine recreationally trained men were pair matched and randomly assigned to the BFR-RE (n = 15) and HL-RE (n = 14) groups. The BFR-RE groups performed bilateral lying leg curl exercise (30-15-15-15 reps, 30-second rest between the sets, 30% 1RM) with BFR cuffs (60% of limb occlusion pressure), whereas HL-RE performed the same exercise (3 × 12 reps, 90-second rest between the sets, 70% 1RM) without BFR cuffs. Hamstring muscle thickness, muscle stiffness, isokinetic muscle strength, and 1RM were assessed at baseline and follow-up after completing a 6-week resistance exercise program (3× a week). Hamstring muscle thickness was assessed by ultrasonography, whereas muscle stiffness was evaluated by shear wave elastography. Isokinetic dynamometry and a 1RM strength test were used to determine muscular strength before and after the exercise program. Statistical significance was set at p < 0.05. No significant effect was found for hamstring muscle strength, thickness, and stiffness for group and group × time interaction, and only a significant main effect of time (p < 0.001) was observed for all outcomes. Both groups experienced significant improvements for all outcomes from baseline to follow-up without any between-group differences. In conclusion, results revealed that BFR-RE can provide similar hamstring muscle strength, thickness, and stiffness compared with HL-RE.

The predictors to self-reported and performance-based physical function in knee osteoarthritis patients: a cross-sectional study.

Osteoarthritis (OA) knee patients have limited ability in physical function, or difficulties with physical tasks and activities may develop disability. This study aimed to observe the predictors of self-reported and performance-based physical function in patients with knee OA by analyzing the impacts of demographic, pathological, and muscle impairment factors. 135 knee OA patients participated in this study to complete self-reported questionnaires using Knee Injury and Osteoarthritis Outcome Score (KOOS). When measuring performance-based physical function, a 6-meter gait speed (6MGS) test was measured to evaluate their mobility, and a 5-time Sit-to-Stand test (5STS) was assessed to evaluate their balance. Pain intensity, knee extensor and flexor muscle strength, age, body mass index (BMI), durations of symptoms, and radiographic severity were also collected. Spearman correlation and stepwise multiple linear regression were used to explore the association and predictors in self-reported and performance-based physical function. BMI and durations of symptoms did not indicate any significant correlation with either self-reported or performance-based physical function. Age is significantly negatively associated with 6MGS (r 2 = -0.383, p < 0.01), while knee extensor muscle strength has a moderate correlation with 5STS (r 2 = -0.528, p < 0.01). In the stepwise multiple linear regression models, pain intensity (β = 0.712, p < 0.001), knee flexor muscle strength (β = 0.112, p = 0.042) were significantly associated with self-reported physical function in daily activities and contributed to 55.0% of the variance in KOOS-PF score. Knee muscle strength, including knee extensor (5STS: β = -0.428, p < 0.001) and flexor muscle strength (6MGS: β = 0.367, p < 0.001), were the main predictors with performance-based physical function. Pain intensity was the leading risk factor of self-reported physical function, and knee flexor muscle strength contributed as well. The severity of knee OA, durations of symptoms and BMI did not contribute to physical function. However, knee extensor and flexor muscle strength were the main predictors of performance-based performance. Our results show that strengthening of weak knee muscles in both quadriceps and hamstring muscle strength should be considered a priory consideration in knee OA no matter if people are in the early or end-stage of knee OA.

Operative Repair of Hamstring Injuries From the Jackling Position in Rugby.

The jackling position within rugby has not been previously described as a mechanism for proximal hamstring injuries. Acute surgical repair of proximal hamstring avulsion injuries sustained from the jackling contact position enables a return to a previous level of sporting activity with low risk of recurrence. Case series; Level of evidence, 4. This study included 54 professional rugby players (mean age, 26 ± 4.8 years) who underwent acute primary surgical repair of complete, proximal hamstring avulsion injuries. The mean follow-up time was 17 months (range, 12-24 months). Mean isometric hamstring strength and function testing was performed at 3 months and 1 year after repair. Of the 54 players, 51 (94.4%) returned to their preinjury level of sporting activity. The mean time from surgical repair to full sporting activity was 7 months (range, 4-12 months). No patients had recurrence of the primary injury. At 1 year postoperatively, patients had significantly restored mean isometric hamstring muscle strength when compared with the uninjured leg at 0° (98.4% ± 2.8%), 15° (95.9% ± 2.9%), and 45° (92.9% ± 4.1%); improved Lower Extremity Functional Score (78.0 ± 2.0); and improved Marx activity rating score (14.3 ± 1.5) (P < .001 for all). Acute surgical repair of proximal hamstring avulsion injuries caused by the contact jackling position produced a high return to preinjury level of sporting activity, increased muscle strength, and improved functional outcome scores, with a low risk of recurrence at short-term follow-up.

Tibiofemoral bone configuration is not associated with hamstring muscle strength in male and female patients with ACL reconstruction.

Previous evidence indicated that the tibiofemoral bone configuration might elevate the risk of an anterior cruciate ligament (ACL) injury. Furthermore, a low hamstring-to-quadriceps muscle ratio predisposes especially females to unfavourable knee kinematics. The primary objective of the present study was to investigate sex-specific associations between tibiofemoral bone geometry and isokinetic knee flexion torque in patients with primary ACL injury followed by ACL reconstruction. N = 100 patients (72 = male, 28 = female, age = 31.3 ± 10.2, body mass index = 25.3 ± 3.6) with primary ACL rupture with isokinetic knee flexion torque assessments before and 6 months after ACL reconstruction surgery were analysed. Magnetic resonance imaging scans were analysed for medial posterior tibial slope (MPTS) and lateral posterior tibial slope, notch width index (NWI) and lateral femoral condyle index (LFCI). Additionally, isokinetic knee flexion torque (60°/s) and hamstring-quadriceps ratios were evaluated. Subsequently, functional parameters were correlated with imaging data for gender subgroups. The findings showed that presurgical isokinetic knee flexion torque was not associated with any marker of femoral or tibial bone geometry. Further, while significant differences were observed between female (0.883 ± 0.31 Nm/kg) and male (1.18 ± 0.35 Nm/kg) patients regarding preoperative normalized knee flexion torque (p < 0.001), no significant sex differences were found for percentage increases in normalized knee flexion torque from presurgery to postsurgery. Generally, female patients demonstrated significantly higher MPTS magnitudes (p < 0.05) and lower LFCI values (p < 0.05) compared to men. The present results demonstrated no association between tibial or femoral bone geometry and muscle strength of the hamstrings in patients with ACL reconstruction, indicating an important mismatch of muscular compensation to deviations in bone geometry. There were no sex-specific differences in tibiofemoral bone parameters. Level III.

The effect of chronic leg press exercises on hamstring muscle length and different vertical jump performance

Background and Study Aim. As it is known, chronic resistance exercises cause limitations in some joints and this negatively affects the normal range of motion. In the present study, it was aimed to analyse the quadriceps-hamstring balance by analysing different vertical jump performances after six weeks of leg press exercise. Material and Methods. Eleven university students aged between 18-30 years were included in this study. The hamstring muscle length, 1 repetition maximum (1-RM) leg press performance were analysed before and after six weeks of leg press exercise. In addition, the vertical jump performances of the participants were analysed with My Jump 2 software programme. In this study, counter movement jumps (CMJ) and squat jump (SJ) performances of the participants were determined. Results. According to the findings, 1 repetition maximum (1-RM) leg press performance and hamstring length of the participants improved significantly (t=-7.609, ES: -2.29, p&lt;.001; t=-2.540, -0.76, p=.029, respectively). CMJ and SJ parameters of the participants did not change (p&lt;0.05). It was concluded that the lengthened hamstring length after the leg press exercise programme had a positive relationship with vertical jump height (r=0.656, p=0.028), flight duration (r=0.663, p=0.026), speed (r=0.657, p=0.028), and average speed (r=0.669, p=0.024). These relationships were observed among CMJ parameters following the exercise programme. Likewise, a positive correlation was found between hamstring length, which lengthened after the leg press exercise programme, and vertical jump height (r=0.625, p=0.040), flight duration (r=0.646, p=0.032), speed (r=0.646, p=0.032), and average speed (r=0.637, p=0.035). These correlations were identified among the SJ parameters after the exercise. Conclusions. As a result, it was determined that chronic leg press exercises positively affected hamstring muscle length and muscle strength. Different vertical jump performances such as CMJ and SJ did not change. However, the relationship between hamstring length and vertical jump parameters is interesting.

Effectiveness of a sensorimotor exercise program on proprioception, balance, muscle strength, functional mobility and risk of falls in older people.

Sensory systems provide the necessary information for a motor response to be provided. In this sense, the objective of this study is to evaluate the effectiveness of a sensorimotor exercise program on proprioceptive acuity, balance, muscle strength, functional mobility and risk of falls in institutionalized elderly. 56 participants (84.6 ± 8.4years) were randomly distributed between the control (CG, n = 28) and intervention groups (IG, n = 28). The CG performed a protocol based on warm-up, muscle strengthening and warm down and the IG performed the same intervention, with the addition of sensorimotor exercises. Joint Position Sensation (JPS) was evaluated in both limbs at angles of 20° and 45°, balance, functional mobility, fear of falling in the elderly and muscle strength of quadriceps, hamstrings, adductors and abductors in both limbs, before and after the 12weeks of intervention. Both groups showed gains in muscle strength. When analyzing functionality through Timed Up and Go (TUG), before and after for each group separately, both showed a significant difference (CG p = 0.002; IG p < 0.001). For the Short Physical Performance Battery (SPPB) variable, there were significant differences in IG in balance (p < 0.001), gait speed time (s) (p = 0.004) and sit-to-stand (p = 0.002). In JPS, significant differences were recorded for Absolute Error 45° Non-Dominant (p = 0.045) and Relative Error 45° Non-Dominant (p = 0.045) in the CG and Relative Error 45° Non-Dominant for IG (p = 0.018). In the Falls Efficacy Scale International (FES-I) variable there were significant improvements in the CG (p = 0.006) and in the GI (p = 0.002). However, only IG showed significant improvements (p = 0.013) for Activities-Specific Balance Confident (ABC) in a comparison between before and after the 12-week research period. When comparing the differences verified with the intervention between CG and IG, only balance SPPB (p < 0.001) and sit-to-stand SPPB (p = 0.022) showed significant values. He effectiveness of sensorimotor exercises provides balance gain in the elderly (p < 0.001) and positively impacts their confidence (p = 0.013) when performing their duties. It is concluded that the protocol presented in its different levels of difficulty is effective and important for the quality of life of the institutionalized sedentary elderly.

Reliability and validity of the new portable Nordic hamstring test device (IVMES H-Bord)

The aim of this study is to determine the reliability and validity of the IVMES H-Bord eccentric hamstring strength measurement device. Thirty-eight healthy male athletes (age: 20.9 ± 2.11 years, height: 1.79 ± 0.03 m, body weight: 76.6 kg, body mass index: 22.6 ± 0.69 kg/m2) participated in this study. Each test protocol was applied in eccentric mode and isometric mode respectively. Between-session test-retest reliability of the IVMES H-Bord was analyzed for the intraclass correlation coefficient (ICC) with 95% coefficient intervals (CI). Validity of the IVMES H-Bord was examined for eccentric mode (NHTecc), and isometric mode (NHTiso) using Pearson’s correlation coefficient with 95% CI and limits of agreement. Bland-Altman plots were also created to provide a representation of the agreement between two test devices. Strong correlations, good ICC values and acceptable typical errors of the estimate were observed between the NHT and isokinetic strength testing (IST) during both limbs with no proportional bias for validity analysis. In conclusion, the “IVMES H-Bord” is a reliable and valid measurement device for eccentric hamstring muscle strength and it provides important advantages for medical staff, fitness coaches and practitioners because it is portable, low cost, and field-based assessment.

Efficiency of a structured squat-based program in knee osteoarthritis rehabilitation

BACKGROUND: Squat exercise, in which eccentric and concentric contractions are present simultaneously in different muscle groups, is one of the closed kinetic chain exercises commonly used in knee rehabilitation. OBJECTIVE: In the scope of the study, our objective is to determine the effectiveness of a structured squat-based exercise approach in patients with knee osteoarthritis. METHODS: In this study, 75 patients diagnosed with knee osteoarthritis were randomly assigned to three distinct groups: isoinertial exercise, a combination of home exercise and electrotherapy, and exercise solely. The assessment encompassed the application of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Time Up and Go test, evaluation of quadriceps and hamstring muscle strength and activation levels, along with pain threshold assessment. The treatment program was administered three days a week over a span of eight weeks and was assessed both prior to and following the intervention. RESULTS: Across all groups, considerable enhancements were noted in the majority of parameters. Particularly noteworthy were the substantial improvements observed in the first group, specifically concerning WOMAC total score (p = 0.001), muscle strength, activation levels (p = 0.001), and pain tolerance (p = 0.05). CONCLUSIONS: In the group in which we applied isoinertial exercise, a positive increase was observed in most of the parameters.We suggest that isoinertial exercise applications, which are generally encountered in sports fields, should be used in different fields in future studies.

The Effect of Combining Blood Flow Restriction with the Nordic Hamstring Exercise on Hamstring Strength: Randomized Controlled Trial.

(1) Background: It is a matter of curiosity what effect the blood flow restriction (BFR) method, which is usually combined with low-intensity resistance exercises, will have when used with high-intensity eccentric exercises. (2) Methods: The present study examined the effects of combining BFR with nordic hamstring exercises (NHEs) on hamstring muscle strength, bilateral deficit (BLD), and training volume. Thirty young female volleyball players, who trained three times a week, participated voluntarily in the study. These players were stratified into three groups, each comprising ten individuals: a control group (CG), an NHE group, and an NHE + BFR group. Hamstring muscle strength and BLD values were determined using an H-BORD device, while training volume was measured in terms of sets and repetitions. (3) Results: Statistical analysis revealed that there were no statistically significant differences in non-dominant and dominant leg peak torque parameters in the exercise groups (F = 2.65; p = 0.097; ηp2 = 0.17; F = 1.15; p = 0.0334; ηp2 = 0.084), while the total training volume was lower in the NHE + BFR group. (4) Conclusions: As a result, it was seen that adding the BFR method to NHE did not provide additional gains. However, due to the low training volume of BFR + NHE, it may be recommended to apply BFR together with NHE to athlete groups.

A Comparison of Different Strength Measurement in Taekwondo: Herman Trainer, Manual Tester, and Standing Long Jump.

Background and Objective: The accurate prediction of strength development relies on identifying the most appropriate measurement methods. This study compared diverse strength measurement techniques to assess their effectiveness in predicting strength development. Participants were taekwondo athletes competing at the red-black belt level or above. Methods: Technical striking forces (palding, dollyeo chagi, dwit chagi, and yeop chagi) were measured using a Herman Digital Trainer fixed to a striking stand. Quadriceps and hamstring strength were assessed with a Lafayette force measuring device. Explosive leg strength was evaluated through a standing long jump test, normalized for leg length. The Pearson correlation coefficient was used to examine relationships between measurement methods. Results: The standing long jump test showed no significant correlation with other strength assessments. A moderate positive correlation was found between Herman digital trainer measurements and Lafayette digital hand-held dynamometer results. A high positive correlation (r = 0.736, p < 0.001) emerged between hamstring strength and palding chagi technical strike force results. Technical strike kicks showed a significant positive correlation with each other and, also, a right foot-left foot correlation was observed. Conclusions: It was concluded that the standing long jump test, which was shown as one of the explosive leg strength measurement methods in field studies as an alternative to laboratory tests, did not correlate with other strength tests; therefore, this test is weak and insufficient to predict strength skills in taekwondo. In addition, this study showed that the hamstring muscle was more predictive in the measurement of technical strength. In future studies, it might be more useful to measure hamstring muscle strength or technical kick strength instead of a standing long jump field test.

The Effectiveness of Kinesio-Taping and Muscle Energy Technique Versus Knee Strengthening Exercises on Pain and Function in Subjects with Osteoarthritis of the Knee

Background: An approach known as Kinesio-taping will be used to support the knee joint and muscle. MET isa sort of manual therapy that uses moderate isometric contractions to relax the muscles and reduces discomfort,stress and strain. It also prevents knee instability by enhancing quadriceps and hamstring muscle strength andfunction in patients with OA knees.Objective: The purpose of the study was to investigate the effectiveness of Kinesio-taping and muscle energytechniques for pain and function in terms of NPRS and KOOS in subjects with OA knee.Methodology: Forty osteoarthritis patients were randomly assigned to one of two groups (A or B). Group A(n=20) will receive Kinesio-taping and (MET) post-isometric relaxation for the hamstring, quadriceps, andgastrocnemius muscles along with interferential therapy. Group B (n=20) will receive knee strengthening exercisesfor both hamstring and quadriceps and interferential therapy for a period of thrice a week for 6 weeks. The NPRS(numerical pain rating scale) and KOOS (knee injury and osteoarthritis outcome score) were used to assess painand functional improvement before and after the tests.Results: Group A showed a significant mean difference (P = &gt;0.001) between the NPRS and KOOS. Hence Group-AKinesio-taping and muscle energy technique along with IFT are significant in treating individuals with pain andfunction in Osteoarthritis of the knee.Conclusion: This study concluded that the Kinesio-taping and MET (post isometric relaxation) with IFT (GroupA) shows effectiveness in improving the pain and function in the OA knee.

Investigating the Effects of Blood Flow Restriction Exercises on Strength and Cross Section Area of Hamstring Muscles and Tendons: A Case Report

Introduction: Hamstring injuries are one of the most common tendon injuries, especially in sports that require running and jumping. A comprehensive training program can help athletes to prevent this injury. Among suggested exercises, the Nordic eccentric training can reduce the injury rate by up to 50%; however, it is a high-load exercise that cannot be prescribed in the first stages of rehabilitation. Here, we describe a football player who used low-load resistance exercise with blood flow restriction as an alternative method to strengthen their hamstring after nine months of anterior cruciate ligament reconstruction surgery&#x0D; Case Description: A 19-year-old non-professional footballer with a body mass index of 22.18 kg/cm2 was invited to participate in this study. The variables examined included strength and cross-sectional area of the hamstring muscles (mean and maximum strength) and the crosssectional area of the hamstring tendons at their origin. The treatment program included a seated hamstring curl with a load of 30% 1 RM with blood flow restriction for four weeks (thrice a week).&#x0D; Results: The hamstring muscle strength improved by 6.54%, and the cross-sectional area of the muscles and tendons changed as follows: Semimembranosus (tendon=0.07%, muscle=2.57%), semitendinosus (tendon=0.00%, muscle=-4.04%), and biceps-femoris (tendon=5.5%, muscle=4.34%).&#x0D; Conclusion: Low load resistance training with blood flow restriction in this athlete improved the strength and cross-sectional area of the hamstring muscles as well as the cross-sectional area of the tendons. The changes observed in tendon, and muscle cross-sectional areas were more prominent for biceps-femoris. This case showed that a training program with blood flow restriction may be a good alternative for people who cannot tolerate high-load exercises in the early stages of their rehabilitation. Doing more extensive studies with more cases and a control group in the future can help our knowledge in giving the best exercise prescription to our patients.

CORRELAÇÃO ENTRE TESTES FUNCIONAIS E AVALIAÇÃO ISOCINÉTICA DO JOELHO EM ATLETAS CORREDORES DE RUA

ABSTRACT Introduction: The assessment of biomechanical changes related to the lower limbs is necessary in clinical practice to measure the potential risks of injury and the influences on existing dysfunction. Biomechanical changes related to previous ankle injuries are known to influence the performance of the entire lower limb. Objective: The aim of this study was to correlate muscle strength tests, performance tests and ankle stability with the Single Hop Test (SHT). Methods: 82 amateur runners were evaluated with isokinetic tests of quadriceps and hamstring muscle strength, as well as Y Balance Test (YBT), Weight-bearing Lung Test (WBLT), and the SHT. Results: The results showed there was a significant correlation between the SHT and the YBT in subjects with hamstring/quadriceps ratio (I/Q ratio) &lt;0.55, and the length of the unilateral SHT with the peak torque of ipsilateral knee extensors. Conclusion: The study was successful in correlating the functional tests in question with the results obtained in isokinetic dynamometry. Level of Evidence V; Cross-Sectional Study.