Isometric Knee Extension Strength Research Articles

#1874 Comparative analysis of rehabilitation outcomes in hospitalized hemodialysis vs. non-hemodialysis patients: a retrospective cohort study

Abstract Background and Aims The hospitalization rate of patients undergoing hemodialysis (HD) is high, due to complications related to renal failure and hemodialysis treatment. Therefore, it is crucial to provide rehabilitation for hospitalized HD patients to improve their activities of daily living (ADL) and physical functions, so as to enable them to be discharged home, resume outpatient dialysis, and avoid re-hospitalization. However, the effectiveness of rehabilitation to improve the ADL and physical functions may differ between hospitalized patients undergoing HD (HD patients) and hospitalized patients not undergoing HD (non-HD patients), depending on their pathological conditions and influence of the HD treatment. The aim of the present study was to compare the outcomes of rehabilitation between hospitalized HD patients and non-HD patients. Method This was a retrospective cohort study. The inclusion criteria were hospitalized patients who received rehabilitation between April 2017 and February 2023. The exclusion criteria were patients who discontinued rehabilitation, were transferred to other hospitals, or died during the rehabilitation period. Rehabilitation consisted of physical therapy and/or occupational therapy provided six times a week, for both hospitalized HD and non-HD patients. The rehabilitation program comprised balance training, aerobic exercises, resistance training, and ADL training to prepare the patients for discharge to their homes. We measured several outcomes in the study, including the daily duration of rehabilitation (min/day), length of hospital stay (days), Barthel index (BI), as the ADL index, at the time of admission and discharge, grip strength and isometric knee extension strength (IKES) as muscle strength indices, and the 10-meter walking speed, timed up and go test (TUG), and short physical performance battery (SPPB) as mobility function indices. For the statistical analysis, missing values were completed by using multiple imputation methods. The inverse probability weighting (IPTW) method was used to match the HD group and non-HD group to adjust for confounding factors. The outcomes between the groups were then compared using a generalized linear model analysis. All procedures in the present study were conducted with the approval of the ethics committee of Seirei Christopher University. Results Of 1002 patients who were registered for the study, 100 patients who discontinued rehabilitation, were transferred to other hospitals, or died were excluded, and the data of the remaining 902 patients (765 of the non-HD group and 137 of the HD group) were included in the analysis in this study. The results of the generalized linear model analysis revealed a lower daily duration of rehabilitation [43.3(0.6) vs. 38.8(1.2) min/day, p=0.0003] and longer length of hospital stay [48.5(0.5) vs. 58.1(2.3) days, p=0.0108] in the HD group. In addition, the 10-meter walking speed [0.75(0.02) vs. 0.66(0.03) m/s, p=0.003] and scores on the TUG [20.8(0.7) vs. 24.3(1.0) sec, p=0.0021] and SPPB [6.3(4.57) vs. 4.7(0.6) points, p=0.0415] at discharge were also significantly lower in the HD group as compared with the non-HD group. There was no difference in the ability for ADL or muscle strength at discharge between the two groups. Conclusion This study was the first to demonstrate a lower daily duration of rehabilitation and longer hospital stay in hospitalized HD patients. Furthermore, rehabilitation had a lower impact on the mobility indices in HD patients as compared with non-HD patients. Although there was no difference in the ability for ADL or muscle strength at discharge between the two groups, HD patients exhibited a significantly lower ability for mobility functions, including a lower gait speed and lower scores on the TUG, and SPPB assessments. Therefore, rehabilitation efforts in HD patients need to be improved by securing more time for inpatient rehabilitation and promoting mobility function improvement.

Free-Living Sit-to-Stand Characteristics as Predictors of Lower Extremity Functional Decline Among Older Adults.

Habitual strength and power-demanding activities of daily life may support the maintenance of adequate lower-extremity functioning with ageing, but this has been sparingly explored. Hence, we examined whether the characteristics of free-living sit-to-stand (STS) transitions predict a decline in lower-extremity functioning over a 4-year follow-up. 340 community-dwelling older adults (60% women, age 75, 80 or 85 years) participated in this prospective cohort study. At baseline, a thigh-worn accelerometer was used continuously (3-7 days) to monitor the number and intensity of free-living STS transitions. A decline in lower-extremity functioning was defined as a drop of ≥2 points in the Short Physical Performance Battery (SPPB) from baseline to follow-up. Maximal isometric knee-extension strength was measured in the laboratory. 85 participants (75% women) declined in SPPB over 4 years. After adjusting for age, sex, and baseline SPPB points, higher free-living peak STS angular velocity (odds ratio [OR] = 0.70; 95% confidence interval [CI] = 0.52-0.92, per 20 deg/s increase) protected against a future decline. When adjusting the model for maximal isometric knee-extension strength, the statistical significance was attenuated (OR = 0.72; 95% CI = 0.54-0.96, per 20 deg/s increase). Performing STS transitions at higher velocities in the free-living environment can prevent a future decline in lower-extremity function. This indicates that changes in daily STS behavior may be useful in the early identification of functional loss. Free-living peak STS angular velocity may be a factor underlying the longitudinal association of lower-extremity strength and performance.

The Impact of Multimorbidity Patterns on Changes in Physical Activity and Physical Capacity Among Older Adults Participating in a Year-Long Exercise Intervention.

This study investigated the impact of multimorbidity patterns on physical activity and capacity outcomes over the course of a year-long exercise intervention, and on physical activity 1year later. Participants were 314 physically inactive community-dwelling men and women aged 70-85years, with no contraindications for exercise at baseline. Physical activity was self-reported. Physical capacity measurements included five-time chair-stand time, 6-minute walking distance, and maximal isometric knee-extension strength. The intervention included supervised and home-based strength, balance, and walking exercises. Multimorbidity patterns comprised physician-diagnosed chronic disease conditions as a predictor cluster and body mass index as a measure of obesity. Multimorbidity patterns explained 0%-12% of baseline variance and 0%-3% of the change in outcomes. The magnitude and direction of the impact of unique conditions varied by outcome, time point, and sex. Multimorbid older adults with no contraindications for exercise may benefit from multimodal physical training.

The impact of malnutrition on the effectiveness of intradialytic exercise in hemodialysis patients: amulticenter cohort study.

Low physical function can be effectively improved via intradialytic exercise. However, the association between the effects of intradialytic exercise on physical function and malnutrition severity has not been studied extensively. This study aimed to investigate the impact of nutritional status severity on physical function in patients undergoing hemodialysis with low physical function to whom intradialytic exercise was prescribed. The participants were patients with decreased mobility [walking speed < 1.0m/s and/or Short Physical Performance Battery (SPPB) < 12] who had been undergoing hemodialysis thrice a week for 6months and performing intradialytic exercise program. Patients were divided into groups based on the Geriatric Nutritional Risk Index (GNRI) [Non-malnutrition group (GNRI > 98), Gentle/slim malnutrition group (GNRI ≤ 98, GNRI ≥ 92), Mild malnutrition group (GNRI < 92, GNRI ≥ 82), Severe malnutrition group (GNRI < 82)]. The primary outcomes were Grip strength, isometric knee extension strength (IKES), SPPB, and 10-m walking speed measured at baseline and at 6months. Statistical analyses were performed using a linear mixed-effects model with the intention-to-treat analysis, including within-group analysis and between-group comparison. A total of 805 participants were included in the study. Within-group comparisons showed significantly improved IKES, 10-m walking speed, and SPPB improved, except in the Severe malnutrition group. Grip strength significantly improved in the Gentle/slim and mild malnutrition groups. Between-group comparison with controls showed that the improvement in Grip strength was significantly bigger in the Gentle/slim malnutrition group [0.98 (0.15to1.82)kg] than in the non-malnutrition group. However, IKES in the Severe malnutrition group [-5.14 (-9.18 to -1.10) %] less significantly improve than that in the non-malnutrition group. No significant differences were found in the other indices. In patients with severe malnutrition, the changes in IKES scores resulting from Intradialytic exercise were significantly smaller than those observed in non-malnourished patients. Therefore, it is necessary to initiate suitable nutritional and exercise therapy based on the severity of malnutrition.

Maximal Lower Limb Strength in Patellar Tendinopathy: A Systematic Review With Meta-Analysis.

To investigate whether lower limb strength is reduced in people with patellar tendinopathy (PT) compared with asymptomatic control individuals or the asymptomatic contralateral limb. MEDLINE, PubMed, Scopus, and Web of Science. To be included in the systematic review and meta-analysis, studies were required to be peer reviewed, published in the English language, and case control investigations; include participants with a clinical diagnosis of PT and an asymptomatic control or contralateral limb group; and include an objective measure of lower limb maximal strength. We extracted descriptive statistics for maximal strength for the symptomatic and asymptomatic limbs of individuals with PT and the limb(s) of the asymptomatic control group, inferential statistics for between-groups differences, participant characteristics, and details of the strength-testing protocol. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for analytical cross-sectional studies. Of the 23 included studies, 21 reported knee strength, 3 reported hip strength, and 1 reported ankle strength. Random-effects models (Hedges g) were used to calculate the pooled effect sizes (ESs) of muscle strength according to the direction of joint movement and type of contraction. The pooled ESs (95% CI) for maximal voluntary isometric contraction knee-extension strength, concentric knee-extension strength, and concentric knee-flexion strength were 0.54 (0.27, 0.80), 0.78 (0.30, 1.33), and 0.41 (0.04, 0.78), respectively, with all favoring greater strength in the asymptomatic control group. Researchers of 2 studies described maximal eccentric knee-extensor strength with no differences between the PT and asymptomatic control groups. In 3 studies, researchers measured maximal hip strength (abduction, extension, and external rotation), and all within-study ESs favored greater strength in the asymptomatic control group. Isometric and concentric knee-extensor strength are reduced in people with PT compared with asymptomatic control individuals. In contrast, evidence for reduced eccentric knee-extension strength in people with PT compared with asymptomatic control individuals is limited and inconsistent. Although evidence is emerging that both knee-flexion and hip strength may be reduced in people with PT, more examination is needed to confirm this observation.

The Influence of Strength and Sport Exposure on Psychological Readiness After ACL Reconstruction.

Among young athletes returning to sport after anterior cruciate ligament reconstruction (ACLR), the extent to which psychological readiness is influenced by factors beyond the psychological domain is largely unknown. Young athletes with recent sport exposure and higher quadriceps strength will demonstrate higher psychological readiness within 8 weeks of medical clearance to return to sport (RTS) after ACLR. Cross-sectional study. Level 3. A total of 38 young athletes after primary ACLR completed testing within 8 weeks of medical clearance to RTS. All participants completed isometric knee extension strength testing, in addition to the ACL Return to Sport after Injury (ACL-RSI) questionnaire. Athletes who participated in sport between time of medical clearance to RTS and date of study enrollment were categorized as SPORT-YES. Those who had not yet participated in sports were categorized as SPORT-NO. Multiple linear regression analyses were used to determine differences in ACL-RSI scores based on quadriceps strength and sport exposure status, while adjusting for age and sex. Of the 38 participants, 20 (52.6%) were categorized as SPORT-YES. The regression model estimating overall ACL-RSI score (P < 0.01, adjusted R2 = 0.389) included significant independent contributions from age, sex, and sport exposure variables (age: P = 0.01, β [95% CI] = -2.01 [-3.54, -0.48]; sex (male): P = 0.02, β [95% CI] = 12.50 [2.36, 22.64]; strength: P = 0.51, β [95% CI] = -2.47 [-10.07,5.13]; sport exposure: P < 0.01, β [95% CI] = 12.89 [3.58, 22.19]). In partial accordance with our hypothesis, recent sport exposure was significantly associated with higher ACL-RSI scores among young athletes in the weeks after medical clearance to RTS after ACLR, while quadriceps strength was not. Future prospective work is needed to determine the existence and direction of causal relationships between exposure to sport environment and psychological readiness among young athletes after ACLR.

Factors associated with improved health-related quality of life due to improvements in physical function and dialysis-related symptoms following intradialytic exercise in outpatients undergoing haemodialysis.

Exercise therapy is a crucial intervention for improving health-related quality of life (HRQOL) in patients undergoing haemodialysis. However, factors that improve HRQOL by improving physical function and dialysis-related symptoms remain unknown. This study aimed to examine the physical function parameters and dialysis-related symptoms that improve HRQOL following intradialytic exercise. This multicentre cohort study included 596 patients who participated in an intradialytic exercise program three times per week for a period of 6months, which comprised of stretching and resistance training. EuroQol 5 dimensions 5-level (EQ5D-5L), grip strength, isometric knee extension strength, 10-m walking speed, Short Physical Performance Battery (SPPB), and improvement in dialysis-related symptoms were measured at the baseline and post-intervention. A linear mixed model was used to analyse the effects of improved physical function and dialysis-related symptoms on improvements in EQ5D-5L. As a physical function index affecting ΔEQ5D-5L, only SPPB showed a significant increase in ΔEQ5D-5L compared with the non-improved group [difference in ΔEQ5D-5L, 0.05 (0.004 to 0.092) point; p < 0.05]). In addition, dialysis-related symptoms with Improved physical conditions [difference in ΔEQ5D-5L, 0.07 (0.02 to 0.13) point] and an Extended walking distance [difference in ΔEQ5D-5L was 0.07 (0.01 to 0.12) point] significantly influenced ΔEQ5D-5L (p < 0.05, both). The improvements observed in the SPPB scores and self-percieved physical fitness and ambulation range, attributable to intradialytic exercise, may potentially improve HRQOL.

EFFECTS OF TWO DIFFERENT FLYWHEEL RESISTANCE TRAINING PROTOCOLS ON EXPLOSIVE KNEE EXTENSION STRENGTH: A PILOT RANDOMIZED STUDY

The aim of our study was to evaluate differences in explosive isometric knee extension strength adaptations after a flywheel squat resistance training programs performed under low- and high-load conditions. Twenty physically active adults were randomly assigned to an individually allocated high- or low-load eight-week training intervention. Isometric knee extension rate of torque development (RTD) and rate of electromyography signal rise (RER) variables were assessed pre and post eight-week intervention. Statistically significant improvements in the RTD slope variables (100 and 200 ms time intervals after the onset of torque rise; p &lt; 0,05) were observed, regardless of the training load used. Normalized averaged vastus lateralis and rectus femoris electromyography (EMG) amplitude decreased in the intervals 80 ms before, and 75, 100 and 200 ms after the onset of activation (all p &lt; 0,05), regardless of the training group. Our results suggest that high- and low-load resistance flywheel training interventions induce similar increases in explosive knee extension strength, accompanied with a decrease in time-analog normalized EMG signal amplitude.

Early- and Late-Stage Benefits of Blood Flow Restriction Training on Knee Strength in Adolescents After Anterior Cruciate Ligament Reconstruction.

Blood flow restriction training (BFRT) after anterior cruciate ligament reconstruction (ACLR) is rising in popularity because of its benefits in reducing muscle atrophy and mitigating knee strength deficits. To investigate the impact BFRT has on adolescent knee strength after ACLR at 2 postoperative time points: at 3 months and the time of return to sport (RTS). Cohort study; Level of evidence, 3. A prospective intervention (BFRT) group was compared to an age-, sex-, and body mass index-matched retrospective control group. Patients aged 12 to 18 years who underwent primary ACLR with a quadriceps tendon autograft were included. Along with a traditional rehabilitation protocol, the BFRT group completed a standardized BFRT protocol (3 BFRT exercises performed twice weekly for the initial 12 weeks postoperatively). Peak torque values for isometric knee extension and flexion strength (at 3 months and RTS) and isokinetic strength at 180 deg/s (at RTS) as well as Pediatric International Knee Documentation Committee (Pedi-IKDC) scores were collected. Differences between the BFRT and control groups were compared with 2-way mixed analysis of variance and 1-way analysis of variance. The BFRT group consisted of 16 patients (10 female; mean age, 14.84 ± 1.6 years) who were matched to 16 patients in the control group (10 female; mean age, 15.35 ± 1.3 years). Regardless of the time point, the BFRT group demonstrated significantly higher isometric knee extension torque compared to the control group (2.15 ± 0.12 N·m/kg [95% CI, 1.90-2.39] vs 1.74 ± 0.12 N·m/kg [95% CI, 1.49-1.98], respectively; mean difference, 0.403 N·m/kg; P = .024). The BFRT group also reported significantly better Pedi-IKDC scores compared to the control group at both 3 months (68.91 ± 9.68 vs 66.39 ± 12.18, respectively) and RTS (89.42 ± 7.94 vs 72.79 ± 22.81, respectively) (P = .047). In adolescents, the addition of a standardized BFRT protocol to a traditional rehabilitation protocol after ACLR significantly improved knee strength and patient-reported function compared to a traditional rehabilitation program alone.

Comparing the associations between muscle strength, walking speed, and mortality in community-dwelling older adults of two birth cohorts born 28 years apart

Reduced age-specific mortality and increased muscle strength and walking speed of current older adults may have altered the relationships between these factors as more people may be above the reserve capacity threshold. We compared the cross-sectional associations between muscle strength and walking speed, and the associations of muscle strength and walking speed with five-year mortality between two population-based cohorts of 75- and 80-year-old people born 28 years apart. Maximal isometric grip and knee extension strength and walking speed were measured in 2017–2018 (n = 726). Mortality was ascertained from registers. The associations were compared with data of same-aged people studied in 1989–1990 with identical protocols (n = 500). The knee extension strength-walking speed relationship showed plateauing at higher strength levels among the later-born men, whereas the earlier-born men and women of both cohorts with lower strength levels were on the linear part of the curve. In the later-born women with lower five-year mortality rate (1.16 vs. 5.88 per 100 person-years), the association between grip strength and mortality was markedly different from the earlier cohort (HR 1.13 [95% CI 0.47–2.70] vs. 0.57 [0.37–0.86]). For knee extension strength and walking speed, the mortality hazards were similar between the cohorts, although statistically non-significant in the later-born women. In men, the later-born cohort showed similar associations as observed in the earlier-born cohort despite having lower mortality rate (2.93 vs. 6.44). Current older adults have more functional reserve that will likely help them to maintain walking ability for longer while also contributing to better survival.

Patient-reported Outcomes and Muscle Strength after a Physiotherapy-led Exercise and Support Brace Intervention in Patients with Acute Injury of the Posterior Cruciate Ligament: A Two-year Follow-up Study.

While outcomes of posterior cruciate ligament (PCL) injuries treated surgically are well described, prospective studies reporting outcomes of exercise interventions are lacking. The purpose of this study was to investigate changes in patient-reported outcomes of a physiotherapy-led exercise and support brace intervention in patients with acute injury of the PCL over a two-year follow-up period. Furthermore, this study sought to investigate changes in isometric knee muscle strength over an eight-month follow-up period, and finally to report conversion to surgical reconstruction over a two-year follow-up period. Case series study, prospective. Fifty patients with an acute injury of the PCL were treated with a brace and a physiotherapy-led exercise intervention and followed prospectively. Changes in patient-reported outcomes were measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS) from baseline (diagnosis) to two-year follow-up. Furthermore, changes in isometric knee flexion and extension strength were measured with a static strength dynamometer from 16 weeks after diagnosis to one-year follow-up. Conversion to surgery was prospectively extracted from medical records. Mean changes were analyzed with a mixed effects model with time as a fixed factor. The IKDC-SKF score improved 28 (95%CI 24-33) IKDC points from baseline to two-year follow-up. Isometric knee flexion strength of the injured knee increased 0.18 (95%CI 0.11-0.25) Nm/kg from 16 weeks after diagnosis to one-year follow-up, corresponding to an increase of 16%. In contrast, isometric knee extension strength of the injured knee did not change (0.12 (95%CI 0.00-0.24) Nm/kg, p=0.042). Over two years, seven patients converted to PCL surgical reconstruction. One and two-year follow-up were completed by 46 and 31 patients, respectively. The physiotherapy-led exercise and support brace intervention demonstrated clinically relevant improvements in patient-reported outcomes and knee flexion strength, and the risk of PCL surgical reconstruction was considered low within the first two years. 3b©The Author(s).

Correlation between Physical Performance and Tensiomyographic and Myotonometric Parameters in Older Adults.

To examine the correlation between physical performance and muscle strength and the variables obtained from tensiomyography and myotonometry. Fifty-two older adults able to complete functional tests participated in this observational study. Variables of maximal radial muscle displacement (Dm) and contraction time (Tc) (using tensiomyography) and muscle stiffness (using myotonometry) of the rectus femoris and vastus lateralis muscles were assessed. Physical performance (Short Physical Performance Battery, Timed Up and Go, Five Times Sit to Stand, and walking speed), isometric knee extension strength, and grip strength were assessed. A correlation analysis was performed between all the variables. A significant correlation between the Short Physical Performance Battery and the rectus femoris (rho = 0.491) and vastus lateralis Dm (rho = 0.329) was found. Significant correlations between the Five Times Sit to Stand Test and the Dm values of the rectus femoris (rho = -0.340) and Dm (rho = -0.304), and stiffness (rho = -0.345) in the vastus lateralis, were also found. No significant correlations were found between tensiomyography and myotonometry, the Timed Up and Go, and walking speed, nor between tensiomyography and myotonometry and grip strength or isometric knee extension strength. Functional tests should be prioritized in the assessment of older adults, but further research into muscle quality using technology is advisable.

Progress in muscle strength of the reconstructed knee and quality of life of the patient after knee rotationplasty: A case report.

Knee rotationplasty (KRP) is a function-preserving surgery that serves as an alternative to above-knee amputation in patients diagnosed with malignant bone and soft tissue tumors around the knee joint. However, the short-term progress of the reconstructed knee in terms of muscle strength is unclear after KRP. This case report describes the progress of a 37-year-old man diagnosed with synovial sarcoma in the distal femur, 1 year after undergoing KRP. Changes in muscle strength of the reconstructed knee and physical function are reported. Physical therapy was started on postoperative day 1 after the KRP, and mobilization proceeded step-by-step with sitting, wheelchair transfer, and crutch walking. Active and passive range-of-motion exercises of the reconstructed knee were started on postoperative day 5. The isometric reconstructed knee extension strength, 10-m walk test, timed up and go test, Musculoskeletal Tumor Society score, Toronto Extremity Salvage Score, and quality of life (QOL) were evaluated. One month postoperatively, muscle strength had increased, and at 6 and 12 months postoperatively, isometric knee extension strength and physical function had improved. Furthermore, activities of daily living and QOL gradually improved over the course of the 12 months. Our case shows the previously unknown course of reconstructed knee muscle strength in the early post-KRP period, with corresponding improvements in physical function, activities of daily living, and QOL.

Supervision during resistance training positively influences muscular adaptations in resistance-trained individuals

ABSTRACT This study compared the effects of supervised versus unsupervised resistance training (RT) on measures of muscle strength and hypertrophy in resistance-trained individuals. Thirty-six young men and women were randomly assigned to one of two experimental, parallel groups to complete an 8-week RT programme: One group received direct supervision for their RT sessions (SUP); the other group performed the same RT programme in an unsupervised manner (UNSUP). Programme variables were kept constant between groups. We obtained pre- and post-study assessments of body composition via multi-frequency bioelectrical impedance analysis (MF-BIA), muscle thickness of the upper and lower limbs via ultrasound, 1 repetition maximum (RM) in the back squat and bench press, isometric knee extension strength, and countermovement jump (CMJ) height. Results showed the SUP group generally achieved larger increases in muscle thickness for the triceps brachii, all sites of the rectus femoris, and the proximal region of the vastus lateralis. MF-BIA indicated increases in lean mass favoured SUP. Squat 1RM was greater for SUP; bench press 1RM and isometric knee extension were similar between conditions. CMJ increases modestly favoured UNSUP. In conclusion, our findings suggest that supervised RT promotes greater muscular adaptations and enhances exercise adherence in young, resistance-trained individuals.

Clinical and biomechanical outcomes following patellar tendon repair with suture tape augmentation

PurposePatellar tendon ruptures (PTR) occur predominantly in middle-aged patients following indirect trauma. The aim of this study was to quantify the short-term results using a suture tape augmentation technique for the repair of PTR.MethodsAll consecutive patients with acute (< 6 weeks) PTR who underwent suture tape augmentation between 03/2014 and 11/2019 at a single institution with a minimum follow-up of 12 months were retrospectively evaluated. Outcome measures included Visual Analog Scale (VAS) for pain, Tegner Activity Scale (TAS) and return to sport rates, Lysholm score, International Knee Documentation Committee subjective knee form (IKDC) as well as Knee Injury and Osteoarthritis Outcome Score (KOOS). Additionally, a standardized clinical examination and an isometric strength evaluation of knee extension and flexion were performed. It was hypothesized that high return to sport rates and good functional outcome would be observed and that the majority of patients would not present with a severe (> 20%) knee extension strength deficit when compared to the contralateral side.ResultsA total of 7 patients (mean age 37.0 ± SD 13.5 years; 6 male/1 female) were available for final assessment at a median follow-up of 17.0 (25–75% IQR 16.0–77.0) months. Three injuries occurred during ball sports, two injuries occurred during winter sports, and one injury each occurred during a motorcycling and skateboarding accident. The average time between trauma and surgery was 4.7 ± 2.6 days. At follow-up, patients reported little pain (VAS: 0 [0–0.4]). Return to sport was possible for all patients 8.9 ± 4.0 months postoperatively at a high level (TAS: 7.0 [6.0–7.0]). Five patients (71.4%) returned to the preinjury level of play, and 2 (28.6%) did not return to the preinjury level of play. Patient-reported outcome measures were moderate to good (Lysholm score: 80.4 ± 14.5; IKDC: 84.2 ± 10.6; KOOS subscales: pain 95.6 ± 6.0, symptoms 81.1 [64.9–89.1], activities of daily living 98.5 [94.1–100], sport and recreation function 82.9 ± 14.1 and knee-related quality of life 75.9 ± 16.3). All patients were very satisfied (57.1%) or satisfied (42.9%) with the postoperative result. No postoperative complications were reported. Strength measurements revealed a severe knee extension deficit in 3 patients (42.9%), but no significant deficit of isometric knee extension or flexion strength in comparison with the contralateral side was observed overall (p > 0.05).ConclusionSuture tape augmentation in acute PTR repair leads to good functional outcome without major complications. Although a severe knee extension strength deficit may occur in some patients postoperatively, an excellent return to sports rate and high patient satisfaction can be expected nonetheless.Level of evidenceRetrospective cohort study; III.

Muscle typology influences the number of repetitions to failure during resistance training

This study examined whether muscle typology (muscle fiber type composition) is related to maximal strength and whether it can explain the high inter-individual variability in number of repetitions to failure during resistance training. Ninety-five resistance training novices (57 males) were assessed for their maximal isometric knee extension strength and muscle typology. Muscle typology was estimated by measuring carnosine in the soleus, gastrocnemius and/or vastus lateralis using proton magnetic resonance spectroscopy. Forty-four subjects (22 males) performed dynamic strength tests (1RM) and 3 sets of leg extensions and curls to failure (60%1RM) to determine the association between muscle typology and (total) number of repetitions. Twenty-one subjects performed additional biceps curls and triceps extensions (60%1RM) to assess influence of exercise, 23 subjects performed additional leg extensions and curls at 80% and 40%1RM to evaluate influence of training load. There was a weak but significant relationship between muscle typology and maximal isometric strength (r = 0.22, p = 0.03) favoring the fast typology individuals. Slow and fast typology individuals did not differ in upper arm and upper leg 1RM. Total number of repetitions was related to muscle typology at 80% (r = -0.42; p = 0.04) and 60% (p = -0.44; p = 0.003) but not at 40%1RM. Slow typology individuals performed more repetitions to failure at 60%1RM in the leg extension (p = 0.03), leg curl (p = 0.01) and biceps curl (p = 0.02). In conclusion, muscle typology has a small contribution to maximal isometric strength but not dynamic strength and partly determines the number of repetitions to failure during resistance training. This insight can help individualizing resistance training prescriptions.

ANTERIOR CRUCIATE LIGAMENT-INJURED FEMALE ADOLESCENTS USE MORE THEIR NON-INJURED LIMB TO PERFORM A COUNTERMOVEMENT JUMP IN RELATION TO THE INJURED LIMB

To investigate if the countermovement jump height differs between ACL injured and uninjured female adolescents and to explore kinematic differences between limbs. Additionally, the association between isometric knee extension strength and jump height was investigated.Thirty-one ACL injured female adolescents (ACLi, 15.3 ± 1.4yrs, 163.9 ± 6.6cm, 63.0 ± 9.3kg) and thirty-eight uninjured (CON, 13.2±1.7yrs, 161.7 ± 8.1cm, 50.6 ± 11.1kg) participated in this study. All participants performed a countermovement jump task, with 3D kinematics collected using a motion analysis system (Vicon, Nexus, Oxford, UK) at 200Hz, and a maximum isometric knee extension task on an isokinetic dynamometer (Biodex Medical Systems, New York, USA) for three trials. The peak torque was extracted from the isometric trials. Independent samples t-test compared the maximum jump height normalised by the dominant leg length between groups, paired samples t-test compared the maximum hip and knee extension and ankle plantar flexion velocities before take-off between limbs in both groups, and a Pearson's correlation test investigated the association between the isometric knee extension strength and jump height.The ACLi jumped 13% lower compared to the CON (p=0.022). In the ACLi, the maximum hip and knee extension and ankle plantar flexion velocities were greater in the non-injured limb, compared to the injured limb; however, no differences between limbs were found in the CON. The isometric knee extension strength of both limbs was positively correlated with jump height (limb 1: r=0.329; p=0.006, and limb 2: r=0.386; p=0.001; whereas limb 1 corresponds to the ACLi injured limb and CON non-dominant limb, and limb 2 to the ACLi non-injured limb and CON dominant limb).ACL injured female adolescents present lower jump height than controls and greater contribution of their non-injured limb, compared to their injured limb, during a countermovement jump task. Also, current results indicate that jump height is positively related to isometric knee extension strength measure.

Preoperative Predictors of Instrumental Activities of Daily Living Disability in Older Adults 6 Months After Knee Arthroplasty

ObjectiveTo investigate preoperative predictors of instrumental activities of daily living (IADL) disability in older adults 6 months after knee arthroplasty (KA). DesignProspective cohort study. SettingGeneral hospital with an orthopedic surgery department. ParticipantsTwo hundred twenty (N=220) patients 65 years or older with total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). InterventionsNot applicable. Main Outcome MeasuresIADL status was evaluated for 6 activities. Participants chose “able,” “need help,” or “unable” according to their capacity of executing these IADL. If they chose “need help” or “unable” for 1 or more items, they were defined as “disabled.” Their usual gait speed (UGS), range of motion for the knee, isometric knee extension strength (IKES), pain status, depressive symptoms, pain catastrophizing, and self-efficacy were evaluated as predictors. Baseline and follow-up assessments were conducted 1 month before and 6 months after KA, respectively. Logistic regression analyses with IADL status as the dependent variable were performed at follow-up. All models were adjusted using age, sex, severity of the knee deformity, operation type (TKA or UKA), and preoperative IADL status as covariates. ResultsIn total, 166 patients completed the follow-up assessment, and 83 (50.0%) reported IADL disability 6 months after KA. Preoperative UGS, IKES on the non-operated side, and self-efficacy were statistically significantly different between those with a disability at follow-up and those who did not and were therefore included in logistic regression models as independent variables. UGS (odds ratio, 3.22; 95% CI, 1.38-7.56; P=.007) was determined as a significant independent variable. ConclusionsThe present study demonstrated the importance of evaluating preoperative gait speed to predict the presence of IADL disability in older adults 6 months after KA. Patients with poorer preoperative mobility should be provided careful postoperative care and treatment.

Interactive Combinations Between Gait Speed and Physical Function at Acute Phase Can Predict the Physical Activity at 2 Years After Total Knee Arthroplasty Using Classification and Regression Tree Analysis

ObjectiveTo clarify the interactive combinations of various clinical factors associated with physical activity (PA) at 2 years after total knee arthroplasty (TKA) using classification and regression tree (CART) analysis. DesignA retrospective cohort study. SettingA single university hospital. Participants286 patients who underwent TKA (N=286). Main Outcome MeasuresPA was assessed preoperatively, 3 weeks, and 2 years after TKA. Physical functions, namely, 10 m walking test (10MWT), timed Up and Go test, 1-leg standing time, isometric knee extension and flexion strength, knee joint stability, knee pain, femora-tibial angle, and the passive knee extension and flexion angle, were measured before surgery as a baseline and 3 weeks after TKA as acute phase. CART analysis was conducted to clarify the interactive combinations that accurately predict the PA at 2 years after TKA. ResultsThe results of CART analysis indicated that gait speed (≥1.05 m/s) at the acute phase after TKA was the primal predictor for the postoperative PA at 2 years. The highest postoperative PA at 2 years was determined by gait speed (≥1.05 m/s) and PA (>74.5) at the acute phase. The PA at baseline and at acute phase, as well as the body mass index were also selected as predictors of postoperative PA at 2 years. ConclusionThe present study suggested that acquiring gait speed (≥1.05 m/s) and PA (>74.5) in the postoperative acute phase is the predictive of a high PA at 2 years after TKA.

Factors Influencing Life Space Mobility in Cancer Survivors Following Hematopoietic Stem Cell Transplantation - Physical Function, Depression, Fatigue, Neighborhood Walkability, and Employment Status.

The level of physical activity in the daily lives of cancer survivors following hematopoietic stem cell transplantation (HSCT) is crucial for maintaining their physical and mental health. Considering that life space mobility (LSM) may limit physical activity, maintaining and expanding LSM is particularly essential for post-HSCT survivors. This study aimed to identify factors influencing LSM in post-HSCT survivors. Thirty cancer survivors after HSCT (14 women, mean age 52.0 ± 12.3 years, 196-3017 days post-HSCT) were included in this cross-sectional study. The assessment encompassed patient characteristics, employment status, life space (Life Space Assessment; LSA), physical function (handgrip strength, isometric knee extension strength, 5 chair standing test, walking speed), depression (Self-rating Depression Scale; SDS), fatigue (Cancer Fatigue Scale), and neighborhood walkability (Walk Score®). The association between LSA and each factor was compared by correlation analysis. Subsequently, multiple regression analysis was conducted, with LSA as the dependent variable and independent variables being outcome measures exhibiting a significant correlation with LSA. Variables significantly correlated with LSA included SDS (r =-0.65, p < .01), employment status (r=-0.60, p < .01), handgrip strength (r = 0.43, p = .02), and isometric knee extension strength (r = 0.40, p = .03). Results of multiple regression analysis show that SDS (β = -0.53, p < .01), employment status (β = 0.48, p < .01), and isometric knee extension strength (β = 0.27, p = .02) were significantly associated with LSA (R2 = 0.74). Depression, employment status, and isometric knee extension strength were identified as factors related to LSM in post-HSCT survivors.