Hamstring Strength Research Articles

Poster 193: Long-Term Outcomes of Partial Proximal Hamstring Avulsion Repair: Average 10-Year Follow-Up

Objectives: While a growing body of literature supports the benefit of surgical repair of complete proximal hamstring avulsions involving all 3 tendons, the optimal treatment for partial proximal hamstring avulsions remains uncertain. Initial nonoperative management of partial proximal hamstring avulsions is typically recommended, but several recent studies have shown improved pain and function at short- and mid-term follow-up. However, the durability of surgical repair at long-term follow-up is unknown. The purpose of this study was to report the long-term outcomes of partial proximal hamstring avulsion repair compared to outcomes at midterm follow-up. It was hypothesized that hamstring function and patient satisfaction would remain stable over time. Methods: All patients who underwent surgical repair of a partial proximal hamstring avulsion by a single surgeon between 2006 and 2018 with a minimum 5-year follow-up were included. Institutional review board approval was obtained prior to study initiation, and all patients signed informed consent. Exclusion criteria were complete avulsions involving all 3 hamstring tendons, retraction > 2 cm, or magnetic resonance imaging (MRI) findings of isolated tendinopathy. All patients had first attempted nonoperative treatment, including nonsteroidal anti-inflammatory drugs and physical therapy. Patient characteristics were collected including age, sex, injury, laterality, sports played, level of participation, length of time from injury to intervention, and length of follow-up. Patients completed a HIPPA-compliant online questionnaire (REDCap) containing the patient-reported outcomes scores of the Lower Extremity Functional Score (LEFS), Marx Activity Rating Scale, custom LEFS (%), and custom Marx (%). A Total Proximal Hamstring Score was calculated by averaging the custom Marx score and the custom LEFS. Patient satisfaction with surgical outcome (yes/no) was also determined. A portion of the included patients had the same outcome measures available from a previous study entailing a minimum 2-year follow-up, with an average follow-up of 6.2 years. Paired comparisons of current outcome scores with earlier scores were performed using a paired Mann-Whitney U test for continuous variables and Fisher exact test for categorical variables. Results: Fifty-three patients (57 hamstrings) with a mean age at surgery of 47.4 years were included at an average follow-up time of 10.1 years. Of the 53 patients, 4 had bilateral injuries and 4 underwent revision surgery. The right (n = 29) and left (n = 28) hamstrings were equally affected with a predominance of female patients (41 female, 16 male). Running was the most common sport at the time of injury (Table 1). Excellent functional outcomes were seen at average 10.1 years (Table 2). 91.2% of patients were satisfied with the results of surgery and were able to return to their desired sport at an average of 10.9 months after surgery. Nearly 88% of hamstrings considered their strength to be >75% strength of the contralateral side, with approximately 58% of hamstrings reporting equal (100%) strength. When comparing the 44 partial hamstring repairs with outcome scores available at both midterm (6.2 years) and long-term follow-up (10.7 years), only the Marx and custom Marx scores were found to decline with time. Scores for LEFS, custom LEFS, Total Proximal Hamstring, satisfaction, and subjective strength were unchanged between midterm and long-term follow-up (Table 3). Conclusions: Excellent patient-reported outcomes and high levels of satisfaction were found at 10-year follow-up following partial proximal hamstring avulsion repair. Notably, the LEFS and custom LEFS, which are the most common patient-reported outcome measures used to assess hamstring function following injury, remained high at midterm and long-term follow-up. The Marx (12.5 vs. 8.5) and custom Marx scores (100% vs. 94%) did achieve statistically significant differences between time points, with lower scores at long-term follow-up possibly in part due to self-determined reduction in strenuous activities with aging. Patient-reported satisfaction and subjective strength remained high at long-term follow-up. Surgical repair of partial proximal hamstring avulsions remains a successful and durable treatment strategy in active patients who have failed nonoperative measures at an average follow-up exceeding 10 years.

Poster 227: Prospective Clinical and Radiological Follow-Up Beyond 10 Years in Patients Undergoing Matrix-Induced Autologous Chondrocyte Implantation (MACI) in the Patellofemoral Joint

Objectives: Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated encouraging outcomes in the treatment of knee cartilage defects, though limited research is available on its longer-term (≥10 years) sustainability in the patellofemoral joint. This prospective study sought to present and report the clinical and radiological outcome beyond 10 years in a prospectively recruited cohort of patients undergoing MACI in the patellofemoral knee joint. Methods: The current study included 82 patients (patella = 41, trochlea = 41) assessed at ≥10 years following patellofemoral MACI. Patients were assessed preoperatively and at 2, 5 and ≥10 years via the Knee Injury and Osteoarthritis Outcome score (KOOS), the 36-item Short Form Health Survey (SF-36), the frequency (VAS-F) and severity (VAS-S) of knee pain, patient satisfaction, active knee range of motion (ROM) and peak isokinetic knee extensor and flexor torque. High-resolution magnetic resonance imaging (MRI) assessed pertinent measures of graft outcome as per the magnetic resonance observation of cartilage repair tissue (MOCART) system, as well as an overall MRI composite score. Results were analyzed according to the graft location (patella or trochlea). Results: While no statistically significant differences (p>0.05) were observed between those undergoing patella or trochlea MACI across the majority of demographic (age, weight, BMI), injury history (duration of symptoms) or surgery (defect size, prior procedures, requirement for concomitant patellofemoral re-alignment) variables, a significantly higher (p=0.013) proportion of males was seen in the trochlea MACI group. All patient-reported outcome measures significantly improved (p<0.05), with no differences observed between those undergoing patella or trochlea MACI. No group differences (p>0.05) were observed in active knee flexion or extension ROM between groups, though those undergoing patella (versus trochlea) MACI demonstrated significantly greater postoperative quadriceps (Figure 1) and hamstring strength limb symmetry indices. No statistically significant decline (p>0.05) was seen from 2 years to final follow-up in any MRI-based measure, with no MRI-based differences observed between patella (Figure 2) and trochlea (Figure 3) grafts. In the cohort assessed at ≥10 years post-surgery, 4 patients (patella n=2, trochlea n=2) demonstrated graft failure on MRI, though a further 3 patients (all trochlea) were omitted from ≥10-year review that had already progressed toward total knee arthroplasty. Conclusions: Good clinical scores, high levels of patient satisfaction and adequate graft survivorship were observed at ≥10 years following MACI to the patella or trochlea.

Evaluating the Efficacy of Kinesthesia, Balance, and Vestibulo-Postural Training in Knee Osteoarthritis Management

Background: Knee osteoarthritis (OA) is a common degenerative joint disease that causes pain, reduced mobility, and impaired quality of life. This study compares the efficacy of kinesthesia and balance exercises with isometric strengthening versus vestibulo-postural training using a bipodalic stabilometric platform with isometric strengthening in improving muscle strength and functional independence in knee OA patients. Methods: Thirty subjects with knee OA, aged between 30-60 years, were randomly assigned to two groups. Group 1 (n=15) received kinesthesia and balance exercises along with isometric strengthening exercises, while Group 2 (n=15) received vestibulo-postural training using a bipodalic stabilometric platform combined with isometric strengthening exercises. Both groups performed their respective exercise regimens three times a week for four weeks. Outcomes measured included quadriceps and hamstrings strength using the Manual Muscle Testing (MMT) grading system and functional independence using the Barthel Index score. Results: Group 2 demonstrated significantly greater improvements in quadriceps strength (mean change: 1.34 vs. 0.40; p < 0.001), hamstrings strength (mean change: 1.07 vs. 0.20; p < 0.001), and Barthel Index score (mean change: 20.54 vs. 5.5; p < 0.001) compared to Group 1. The between-group analysis confirmed that vestibulo-postural training with isometric strengthening was significantly more effective in enhancing muscle strength and functional independence in knee OA patients. Conclusion: Vestibulo-postural training using a bipodalic stabilometric platform combined with isometric strengthening exercises significantly improves muscle strength and functional independence in knee OA patients compared to kinesthesia and balance exercises with isometric strengthening. These findings highlight the importance of incorporating dynamic and challenging balance exercises into OA management strategies to optimize patient outcomes and enhance quality of life..

Relationship between hamstring strength and hop performance at 8 and 12 months after ACL reconstruction with hamstring tendon autografts

BackgroundThe relationship between hamstring strength and hop performance after anterior cruciate ligament (ACL) reconstruction with hamstring tendon (HT) autografts has not been well elucidated. The aim was to investigate the relationship between eccentric hamstring strength, assessed with the NordBord, and concentric hamstring strength, assessed with the Biodex, with hop performance at 8 and 12 months after ACL reconstruction.MethodsRegistry study. Patients ≥ 16 years who had undergone primary ACL reconstruction with HT autograft, followed by muscle strength and hop tests at 8 and 12 months were included. Correlations of the relative hamstring strength (Nm/kg or N/kg) and limb symmetry index (LSI) with hop performance were analyzed. Pearson’s correlation coefficient, and coefficient of determination (r2) were used for statistical analysis.ResultsA total of 90 patients were included, of which 48 (53%) were women. The mean age at ACL reconstruction was 27.0 ± 8.0 years. Relative hamstring strength had significant positive correlations with hop performance, ranging from r = 0.25–0.66, whereas hamstring strength LSI had significant positive correlations which ranged from r = 0.22–0.37 at 8 and 12 months after ACL reconstruction. At 12 months, the relative hamstring strength in the Biodex explained 32.5–43.6% of the hop performance in vertical hop height, hop for distance relative to height, and the total number of side hops, whereas the relative hamstring strength in the NordBord explained 15.2–23.0% of the hop performance.ConclusionThe relative hamstring strength in the Biodex test explained 32.5–43.6% of the hop performance, whereas the relative hamstring strength in the NordBord explained 15.2–23.0%. Thus, our findings suggest that relative hamstring strength, especially in the hip-flexed position may be a better indicator of hop performance at 8 and 12 months after ACL reconstruction in patients treated with HT autograft.

The relationship between hamstring strength tests and sprint performance in female Gaelic footballers: A correlation and linear regression analysis.

To investigate the relationships between handheld dynamometer (HHD), isokinetic and Nordic hamstrings exercise (NHE) measurements of knee flexor strength and their association with sprinting performance. Cross-sectional. The relationships between HHD (prone isometric, prone break and supine break knee flexor strength tests), isokinetic and NHE peak knee flexor strength measures were examined using Pearson product correlations on 38 female footballers. A linear regression analysis was also performed for each pair of dependent variables (10 and 30 metre sprint times) and independent predictor variables (average relative peak torque for HHD, isokinetic and NHE testing). There were good correlations between HHD tests (r = 0.81-0.90, p < 0.001, R2 = 0.65-0.82), moderate correlations between HHD and isokinetic peak torque, (r = 0.61-0.67, p < 0.001, R2 = 0.37-0.44) and poor association between the HHD peak torques and isokinetic work (r = 0.44-0.46, p = 0.005-0.007, R2 = 0.20-0.21) and average power (r = 0.39-0.45, n = 36, p = 0.006-0.019, R2 = 0.15-0.22). There was a poor association between NHE peak torque and isokinetic total work (r = 0.34, p = 0.04, R2 = 0.12). No associations between knee flexor strength and sprint times were observed (p = 0.12-0.79, r2 = 0.002-0.086). Moderate to good correlations within HHD testing and poor to moderate correlations between HHD and isokinetic testing were observed. HHD knee flexor torque assessment may be useful to regularly chart the progress of hamstring rehabilitation for female footballers. Knee flexor strength assessments were not associated with sprint times in female footballers. Other aspects of knee flexor strength and sprint performance should be investigated to assist clinicians in making return to running and sprinting decisions in this population.

ACL Reconstruction Using Quadrupled Semitendinosus Versus Double-Stranded Semitendinosus and Gracilis Autograft: 2-Year Results From a Prospective Randomized Controlled Study

Background: A disadvantage of using hamstring tendon autograft consisting of the semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction is pain from tendon harvesting and persistent hamstring weakness. In the tendon-sparing all-inside technique, a quadrupled semitendinosus graft and adjustable-loop cortical fixation are suggested to give less postoperative flexion deficits while displaying overall similar clinical results to the traditional hamstring technique. However, there are a limited number of high-quality studies comparing these techniques with inconsistent results. Purpose: To investigate differences between the all-inside (quadrupled semitendinosus) and traditional hamstring (double-stranded semitendinosus and gracilis) technique regarding (1) self-reported function, (2) hamstring strength, and (3) knee laxity. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 98 patients were randomized to either the all-inside or the traditional hamstring technique. Perioperatively, duration of surgery and graft size were obtained. The International Knee Documentation Committee 2000 Subjective Knee Form score, Knee injury and Osteoarthritis Outcome Score, Tegner Activity Scale score, knee laxity (KT-1000 arthrometer side-to-side difference and pivot shift), range of motion, isokinetic knee strength, and hop test score were collected preoperatively and 2 years postoperatively. Return-to-sport readiness was evaluated 9 months postoperatively. Results: A total of 89 patients completed 2-year follow-up, 45 patients with the all-inside technique and 44 patients with the traditional hamstring technique. There were no significant differences between groups in any of the outcome measures 2 years after surgery, but there was a tendency in the all-inside group toward having increased anterior translation (mean, 3.6 mm vs 2.7 mm), a higher number of revision surgeries (5 patients vs 2 patients), and more patients having +1 and +2 pivot-shift values (29 vs 18 patients) when compared with the traditional group. Conclusion: The all-inside technique yields equivalent results to the traditional hamstring technique 2 years after surgery and should be considered a reliable technique to use for ACL reconstruction. Sparing the gracilis tendon does not lead to less persistent hamstring weakness. Long-term follow-up is needed to further determine whether the tendency of increased anterior translation seen at 2 years postoperatively will lead to a higher risk of graft failure.

The impact of various massage gun percussive therapy protocols on physiological adaptations

Current protocols for delivering percussive therapy (PT) using massage guns are heterogenetic creating a need to establish the impact of study design on physiological measures and the standardisation of future research. This study aimed to determine the most effective protocol on lower body strength, net impulse, and flexibility, and to support the provision of protocol validation for future research. With institutional ethics approval, a convenience sample of recreationally active healthy adults (n = 35; a-priori calculation suggested 34 participants) with no lower body massage gun PT experience, undertook two main protocols; three sessions per week at 2100 rpm or increasing the speed for each session: 1750 to 2100 to 2400 rpm. PT was applied at tolerable pressure for 60 s to each of the quadriceps, gluteals, hamstrings and calves of both legs. Paired-samples t tests (alpha levels: P = .05) assessed pre- and post-intervention data for strength, net impulse, and flexibility. These were collected in all sessions using a dynamometer, My Jump 2 app and goniometer allowing changes for eight different protocols to be reported with Cohen’s d. After three sessions a week involving increments in speed, results showed significant improvements in strength (dominant; non-dominant) of quadriceps (P = .005, d = 0.51; P &lt; .001, d = 0.77), hamstrings (P = .001, d = 0.61; P = .006, d = 0.49) and calves (P &lt;.001, d = 0.69; P = .015, d = 0.44), and flexibility of hamstrings (P &lt; .001, d = 1.14; P &lt; .001, d = 0.74) and calves (P = .04, d = 0.36; P = .005, d = 0.51). Combined lower body muscle strength (quadriceps, hamstrings and calves) increased on average by 10.1% (mean ± 2.14 kg, range ± 1.30-2.98 kg) and flexibility (hamstrings and calves) increased on average by 5.8% (mean ± 1.77°, range ± 1.70-5.66°). A significant improvement (P = 0.33, d = 0.36) was seen in net impulse after three treatments a week at 2100rpm, an increase of 3.2% (mean ± 4.75 N·s). The most effective protocol for gains in lower body strength and flexibility is applying massage gun PT three times a week with increased speeds across sessions (1750, 2100, 2400rpm). For gains in net impulse, the most effective protocol is three applications a week at 2100 rpm. Practitioners using these protocols could target specific improvements in physiological adaptations and in addition, and in addition researchers may wish to adopt these protocols to allow homogenous analysis across study populations in future research.

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.

Pattern of strength recovery differences Exist in Adolescent athletes after anterior cruciate ligament reconstruction when using quadriceps versus Hamstring tendon autograft

ObjectivesTo compare the timeline for post-operative quadriceps and hamstrings strength recovery following anterior cruciate ligament reconstruction (ACLR) using either a quadriceps tendon (QT) or hamstring tendon (HT) autograft. MethodsPatients (≤18 years) who underwent ACLR using autograft QT or HT were included. Isokinetic strength was extracted at 3, 6, and 12 months post-operatively. Effects of time and graft type on quadriceps or hamstring limb symmetry index (qLSI/hLSI) was assessed with two-way repeated measures ANOVA. Between group differences at each time point were assessed with unpaired t-tests. Chi-square and Kaplan-Meir analysis analyzed the proportions of subjects able to achieve ≥90% LSI. ResultsA total of 75 subjects (QT n = 38 HT n = 37,15.8 years) were included. There were significant differences in qLSI, with greater symmetry within the HT group at all time points. A higher proportion of subjects with HT grafts were able to achieve ≥90% qLSI within 12 months of surgery (81% vs 45%, p = 0.001). ConclusionCompared to those with HT autografts, adolescents with QT autografts demonstrate a prolonged timeline for quadriceps recovery. While mean strength values above 90% are achieved, a significantly lower percentage of QT patients are able to achieve 90% qLSI by 12 months post-op.

Study protocol for a randomized controlled trial: evaluating the effect of isokinetic eccentric training of the hamstring on knee function and walking function after total knee arthroplasty

IntroductionTotal knee arthroplasty (TKA) is a widely-used treatment for end-stage knee osteoarthritis. However, it is common for patients to experience issues with knee joint function and abnormal gait following the surgery. Previous studies have primarily focused on concentric contraction of the quadriceps during TKA, neglecting the potential benefits of eccentric isokinetic training for the hamstrings. This protocol outlines a randomized, single-blind, controlled trial aimed at assessing the impact of eccentric isokinetic training for the hamstring muscles on pain, function, and gait in patients after TKA.Methods and analysisFifty participants between the ages of 50 and 80 with knee osteoarthritis undergo unilateral total knee arthroplasty (TKA) for the first time. They will be transferred to the rehabilitation department 10–14 days after the operation. The participants are randomly divided into two groups, with 25 participants in each group: the control group and the Hamstring training group. The Control group will receive routine rehabilitation treatment, while the Hamstring training group will receive a combination of routine rehabilitation treatment and isokinetic eccentric training of the hamstring. The intervention will last four consecutive weeks. Both groups will be assessed at three different times: before the intervention, after 4 weeks of intervention, and 4 weeks after the interventions (follow-up). The primary outcome will be functional capacity (TUGT) and Hospital for Special knee Score (HSS). Secondary outcomes will be knee-related health status (isokinetic knee position perception, Peak torque of hamstring strength), pain intensity (Visual analog scale, VAS) and 3D gait analysis.DiscussionThe study aims to provide relevant evidence on the effectiveness of eccentric hamstring muscle contraction training in improving knee joint function and walking function after TKA.Clinical trial registrationhttps://www.chictr.org.cn/showproj.html?proj=195544, Identifier ChiCTR2300073497.

Addition of anterolateral ligament reconstruction to primary anterior cruciate ligament reconstruction could benefit recovery of functional outcomes

This study aimed to compare functional outcomes sequentially up to 1 year after combined anterior cruciate ligament reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) and isolated ACLR. Fifty patients who underwent ACLR with versus without ALLR were analyzed at four different time points (preoperatively and 3, 6, and 12 months postoperatively). For the functional outcomes, muscle strength and acceleration time (AT) were measured using an isokinetic dynamometer. Proprioception was evaluated using joint position sense and dynamic postural stability. Patient-reported outcomes were measured using the Tampa Scale for Kinesiophobia (TSK-11) scores. Functional performance was assessed using single-leg hop distance (SLHD) and Limb Symmetry Index. In the operated knees, quadriceps (at 6 months postoperatively, p = 0.003) and hamstring (at 6 and 12 months postoperatively, p < 0.001) strength were significantly higher in the combined ACLR and ALLR group than the isolated ACLR group. The TSK-11 (at 6 and 12 months postoperatively, p < 0.001) was significantly lower in the combined ACLR and ALLR group than the isolated ACLR group. SLHD was significantly higher in the combined ACLR and ALLR group than the isolated ACLR group (at 6 months, p = 0.022 and at 12 months, p = 0.024). The addition of ALLR to primary ACLR yielded better muscle performance, fear of movement, and functional performance than isolated ACLR.

A RANDOMIZED CONTROLLED TRIAL ASSESSING TRADITIONAL VERSUS DYNAMIC REHABILITATION REGIMES FOLLOWING SURGICAL REPAIR OF A PROXIMAL HAMSTRING TENDON AVULSION

Proximal hamstring tendon avulsion from the ischial tuberosity is a significant injury, with surgical repair shown to have superior functional outcomes compared to non-surgical treatment. However, limited data exists regarding the optimal rehabilitation regime following surgical repair. The aim of this study was to investigate patient outcomes following repair of proximal hamstring tendon avulsions between a conservative (CR) versus an accelerated rehabilitation (AR) regimen.This prospective randomized controlled trial (RCT) randomised 50 patients undergoing proximal hamstring tendon repair to either a braced, partial weight-bearing rehabilitation regime (CR=25) or an accelerated, unbraced regime, that permitted full weight-bearing as tolerated (AR=25).Patients were evaluated pre-operatively and at 3 and 6 months post-surgery, via patient-reported outcome measures (PROMs) including the Lower Extremity Functional Scale (LEFS), Perth Hamstring Assessment Tool (PHAT) and 12-item Short Form Health Survey (SF-12). Primary analysis was per protocol and based on linear mixed models.Both groups were matched at baseline with respect to patient characteristics. All PROMs improved (p&gt;0.05) and, while the AR group reported a significantly better Physical Component Score for the SF-12 at 3 months (p=0.022), there were no other group differences. Peak isometric hamstrings strength and peak isokinetic quadriceps and hamstrings torque symmetry were all comparable between groups (p&gt;0.05). Three re-injuries have been observed (CR=2, AR=1).After proximal hamstring repair surgery, post-operative outcomes following an accelerated rehabilitation regimen demonstrate comparable outcomes to a traditionally conservative rehabilitation pathway, albeit demonstrating better early physical health-related quality of life scores, without an increased incidence of early re-injury.

Validity and Reliability of Handheld Dynamometry to Assess Isometric Hamstrings and Quadriceps Strength at Varying Muscle Lengths.

The hamstrings are the most commonly injured muscle in sports and are especially injury prone in lengthened positions. Measuring knee muscle strength in such positions could be relevant to establish injury risk. Handheld dynamometry has been shown to be a valid, reliable, and practical tool to measure isometric muscle strength clinically. The aim of this study was to assess the validity and reliability of the assessment of isometric knee muscle strength with a handheld dynamometer (HHD) at various muscle lengths, by modifying the hip and knee angles during testing. Concurrent validity and test-retest reliability. Thirty young healthy participants were recruited. Hamstring and quadriceps isometric strength was measured with a HHD and with an isokinetic dynamometer, over 2 testing sessions, in a randomized order. Isometric strength was measured on the right lower limb in 6 different positions, with the hip at either 0° or 80° of flexion and the knee at either 30°, 60°, or 90° of flexion. Pearson and Spearman correlations were used to assess the validity, and intraclass correlation coefficients were calculated to establish the test-retest reliability of the HHD. Good to excellent reliability and moderate to high validity were found in all the tested muscle length positions, except for the hamstrings in a seated position with the knee extended at 30°. The use of a HHD is supported in the clinical setting to measure knee muscle strength at varying muscle lengths in healthy adults, but not for the hamstrings in a lengthened position (hip flexed and knee extended). These results will have to be confirmed in sport-specific populations.

A RANDOMIZED CONTROLLED TRIAL INVESTIGATING PATIENT RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION UNDERTAKEN WITH A QUADRICEPS VERSUS HAMSTRINGS TENDON AUTOGRAFT

INTRODUCTION &amp; AIMS Anterior cruciate ligament (ACL) tears are common. However, a lack of high-quality evidence exists comparing different graft options in patients undergoing surgical reconstruction (ACLR). This randomized controlled trial (RCT) investigated the course of recovery in patients undergoing ACLR with either a quadriceps (QT) or hamstrings (HT) tendon autograft. METHODS This study randomized 112 patients to one of the two graft reconstruction cohorts (HT=55, QT=57), subsequently undergoing ACLR and a structured rehabilitation program. Patients were assessed pre-surgery and at 6 weeks and 3, 6, 12 and 24 months, with a range of patient-reported outcome measures (PROMs) including the International Knee Documentation Committee form (IKDC) and the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score. Graft laxity, peak isokinetic knee extensor and flexor strength and a 6-hop performance battery were assessed. Limb Symmetry Indices (LSIs) were calculated. RESULTS All PROMs significantly improved (p&amp;lt;0.0001). Apart from the ACL-RSI score which was significantly better (p&amp;lt;0.05) in the HT group at 3, 6 and 12 months, no other group differences (p&amp;gt;0.05) were observed. No group differences (p=0.407) were observed for knee laxity. While the HT group demonstrated significantly greater (p&amp;lt;0.05) quadriceps strength LSIs at 6 and 12 months, the QT group demonstrated significantly greater (p&amp;lt;0.05) hamstrings strength LSIs at 6, 12 and 24 months. The HT group demonstrated significantly greater (p&amp;lt;0.05) LSIs for the single horizontal (6 months), lateral (6 and 12 months) and medial (6 months) hop tests. CONCLUSION The HT group reported a higher level of psychological readiness to return to sport, while demonstrating greater quadriceps strength (and hop test) LSIs. Greater hamstring strength LSIs were observed for the QT cohort. Longer-term review will continue to evaluate RTS and later-stage re-injury between the two graft constructs.

A RANDOMIZED CONTROLLED TRIAL ASSESSING A BRACE-FREE AND ACCELERATED WEIGHT-BEARING PROTOCOL AFTER SURGICAL REPAIR OF ACUTE PROXIMAL HAMSTRING TENDON AVULSIONS

INTRODUCTION &amp; AIMS Proximal hamstring tendon avulsion from the ischial tuberosity is a significant injury, with surgical repair advocated. After surgery, limited data exists regarding the optimal rehabilitation regime with extensive variation in published protocols. This study investigated patient outcomes following a traditionally conservative (CR) versus accelerated (AR) rehabilitation regimen after proximal hamstring tendon repair. METHODS This prospective randomized controlled trial (RCT) allocated 50 patients undergoing proximal hamstring tendon repair to either a braced, partial weight-bearing rehabilitation regime (CR=25) or an accelerated, unbraced regime, that permitted full weight-bearing as tolerated (AR=25). Patients were evaluated pre-operatively and at 3, 6 and 12 months post-surgery, via patient-reported outcome measures (PROMs) including the Lower Extremity Functional Scale (LEFS), Perth Hamstring Assessment Tool (PHAT) and 12-item Short Form Health Survey (SF-12). The single (SHD), triple (THD) and triple crossover (TCHD) hop tests were assessed at 6 and 12 months, as was peak isometric hamstring strength and peak isokinetic knee extensor and flexor torque. RESULTS All PROMs improved (p&amp;gt;0.05) and, while the AR group reported a significantly better Physical Component Score for the SF-12 at 3 months (p=0.022), as well as a lower severity of hamstring pain at 12 months (p=0.032), there were no other group differences. Peak isometric hamstrings strength and peak isokinetic quadriceps and hamstrings torque symmetry were all comparable between groups (p&amp;gt;0.05). While the AR group demonstrated significantly better (p=0.009) limb symmetry for the THD at 6 months, no other hop test differences were seen between groups. Three re-injuries have been observed (CR=2, AR=1). CONCLUSION After proximal hamstring repair surgery, post-operative outcomes following an accelerated rehabilitation regimen were largely comparable to a traditionally conservative

A RANDOMIZED CONTROLLED TRIAL INVESTIGATING FUNCTIONAL RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING A SINGLE VERSUS DOUBLE TENDON HARVEST

INTRODUCTION &amp; AIMS Anterior cruciate ligament (ACL) tears are common. While surgical reconstruction (ACLR) is commonly advocated and a hamstring autograft is the popular choice, hamstring tendon harvest has been linked to reduced hamstring strength and ongoing donor site pain. While traditional surgical techniques required a harvest of both semitendinosus/gracilis tendons, modern harvesting and fixation methods permit a shorter, broader harvest of semitendinosus only. This study investigated donor site pain, strength and functional recovery in patients undergoing ACLR via a single (ST) versus dual (DT) tendon hamstring harvest. METHODS This prospective randomized controlled trial (RCT) allocated 138 patients to ACLR with one of the two hamstring tendon graft options (ST=71, DT=67) followed by a structured rehabilitation program. Patients were assessed pre-surgery and at 3, 6, and 12 months, with a range of patient-reported outcome measures (PROMs) including a validated donor-site morbidity score. Graft laxity, peak isokinetic knee extensor and flexor strength and a 6-hop performance battery were assessed. Limb Symmetry Indices (LSIs) were calculated. RESULTS All PROMs significantly improved (p&amp;lt;0.0001) and were largely similar between groups (p&amp;gt;0.05), apart from significantly less graft morbidity reported in the ST group (p=0.001). No group differences were observed for knee laxity or LSIs for hop measures (p&amp;gt;0.05), nor the LSIs for peak knee flexor (p=0.113) or extensor (p=0.286) torque. CONCLUSION While the ST ACLR group reported significantly less harvest site morbidity, no other subjective or functional differences were observed in patients undergoing ACLR with either a single or dual hamstring tendon autograft harvest.

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.

Effect of Sampling Frequency on a Unilateral Isometric Hamstring Strength Assessment Using Force Plates

AbstractThe purpose of this study was to determine the effect of sampling frequency on the 90–90° (90-degrees hip and knee flexion) isometric hamstring assessment. Thirty-three elite female soccer players (age: 18.7 ± 3.7 years; height: 158.3 ± 5.9 cm; body mass: 62.8 ± 5.5 kg) performed three unilateral trials on a single occasion of the 90–90° isometric hamstring assessment. Force-time data were collected using force plates at 1000 Hz and down sampled to 500-, 250-, and 100 Hz. Peak force (N), force (N) at 100- and 200 ms and average rate of force development (aRFD) (N/s) over a 100- and 200 ms epoch were calculated. A repeated measures of analysis of variance and effect size was used to compare means. Excellent absolute and good relative reliability was observed for peak force across all sampling frequencies. Force at 100- and 200 ms and aRFD over 100 ms and 200 ms resulted poor-moderate relative reliability and poor-excellent absolute reliability. No significant trivial differences were observed for peak force between sampling frequencies (P &gt; 0.05, Cohen’s d = 0.02–0.12). A significant difference (P &lt; 0.001) was identified in 500, 250 and 100 Hz, with small-moderate and small-large increases in force at set time points and aRFD, respectively, in comparison to 1000 Hz (d = 0.21–2.00). Higher sampling frequencies (&gt; 500 Hz) reduces the reliability of time dependent force characteristics, with minimal effect on peak force. Regular monitoring of peak force can be performed with higher sampling frequencies, but lower sampling frequencies would be beneficial to collect reliable rapid-force generating measures.

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.

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.