Isometric Knee Extension Muscle Strength Research Articles

Associations of passive muscle stiffness and muscle echo-intensity with muscle strength

Objective: Muscle tissue parameters including composition and stiffness of muscle can have an important effect on muscle strength. In this study, we aimed to investigate the relationships between muscle echo-intensity (EI), tendon stiffness and muscle strength in young men and women. Methods: Ultrasound B-mode images of the Rectus Femoris (RF), Vastus Medialis (VM) and Patellar Tendon (PT) were acquired in fifty-two healthy subjects (mean age; 27.43±5.3 years). RF, VM and PT stiffness were characterized by shear-wave elastography measurements. Quantitative evaluations were performed, including measurement of muscle and tendon thickness and muscle EI. Isometric knee extension muscle strength was measured using hand-held dynamometer. Results: RF stiffness had a good correlation with muscle strength (r=-0.46, p<0.05) and had a fair correlation with EIRF(r=-0.37,p<0.05), VM stiffness had a good correlation with muscle strength (r=0.42, p<0.05) and had a fair correlation with EIVM (r=-0.43,p<0.05) in women. RF stiffness had a good correlation with muscle strength (r=-0.54, p<0.05), had a good correlation with EIRF(r=-0.41,p<0.05) in men.VM stiffness had a good correlation with muscle strength(r=-0.50; p<0.05), and had a good correlation with EIVM(r=-0.60,p<0.05) in men. EIRF and EIVM had a good relation with muscle strength in men and women (For EIRF; r=-0.46; r=-0.54; for EIVM; r=-0.42; r=-0.50 p<0.05, respectively) Conclusions: This study demonstrates that there is a relationship between isometric muscle strength and passive muscle stiffness, muscle EI. Additionally, muscle EI affects muscle stiffness in healthy men and women. Our results should be considered in elite athletes for whom the strengthening program is important.

The isometric and isokinetic knee extension and flexion muscle strength profile of elite soccer players

BackgroundThis study aimed to further complete normative data sets for the strength profile of the thigh in soccer players by performing isometric and isokinetic measurements in a large sample per player position.MethodsIn total, 364 soccer players were divided into subgroups according to their pitch position. All players performed isometric and isokinetic strength measurements during active competition period using an isokinetic dynamometer (System 3, Biodex®, ENRAF-NONIUS, New York, USA).ResultsIsokinetic strength of m. Quadriceps was significantly (p = 0.023) higher in strikers compared to central midfielders in both the dominant (+ 9%) and the non-dominant (+ 4%) leg. No further differences were found in isometric or isokinetic strength per playing positions.ConclusionsWe have shown that strength profiles do not differ between playing positions on the field. This is valuable information for elite soccer high performance coaches and medical staffs aiming to improve daily training efficiency and rehabilitation of their players.

Functional Limitations and Exercise Intolerance in Patients With Post-COVID Condition

Many patients with post-COVID condition (PCC) experience persistent fatigue, muscle pain, and cognitive problems that worsen after exertion (referred to as postexertional malaise). Recommendations currently advise against exercise in this population to prevent symptom worsening; however, prolonged inactivity is associated with risk of long-term health deterioration. To assess postexertional symptoms in patients with PCC after exercise compared with control participants and to comprehensively investigate the physiologic mechanisms underlying PCC. In this randomized crossover clinical trial, nonhospitalized patients without concomitant diseases and with persistent (≥3 months) symptoms, including postexertional malaise, after SARS-CoV-2 infection were recruited in Sweden from September 2022 to July 2023. Age- and sex-matched control participants were also recruited. After comprehensive physiologic characterization, participants completed 3 exercise trials (high-intensity interval training [HIIT], moderate-intensity continuous training [MICT], and strength training [ST]) in a randomized order. Symptoms were reported at baseline, immediately after exercise, and 48 hours after exercise. The primary outcome was between-group differences in changes in fatigue symptoms from baseline to 48 hours after exercise, assessed via the visual analog scale (VAS). Questionnaires, cardiopulmonary exercise testing, inflammatory markers, and physiologic characterization provided information on the physiologic function of patients with PCC. Thirty-one patients with PCC (mean [SD] age, 46.6 [10.0] years; 24 [77%] women) and 31 healthy control participants (mean [SD] age, 47.3 [8.9] years; 23 [74%] women) were included. Patients with PCC reported more symptoms than controls at all time points. However, there was no difference between the groups in the worsening of fatigue in response to the different exercises (mean [SD] VAS ranks for HIIT: PCC, 29.3 [19.5]; controls, 28.7 [11.4]; P = .08; MICT: PCC, 31.2 [17.0]; controls, 24.6 [11.7]; P = .09; ST: PCC, 31.0 [19.7]; controls, 28.1 [12.2]; P = .49). Patients with PCC had greater exacerbation of muscle pain after HIIT (mean [SD] VAS ranks, 33.4 [17.7] vs 25.0 [11.3]; P = .04) and reported more concentration difficulties after MICT (mean [SD] VAS ranks, 33.0 [17.1] vs 23.3 [10.6]; P = .03) compared with controls. At baseline, patients with PCC showed preserved lung and heart function but had a 21% lower peak volume of oxygen consumption (mean difference: -6.8 mL/kg/min; 95% CI, -10.7 to -2.9 mL/kg/min; P < .001) and less isometric knee extension muscle strength (mean difference: -37 Nm; 95% CI, -67 to -7 Nm; P = .02) compared with controls. Patients with PCC spent 43% less time on moderate to vigorous physical activity (mean difference, -26.5 minutes/d; 95% CI, -42.0 to -11.1 minutes/d; P = .001). Of note, 4 patients with PCC (13%) had postural orthostatic tachycardia, and 18 of 29 (62%) showed signs of myopathy as determined by neurophysiologic testing. In this study, nonhospitalized patients with PCC generally tolerated exercise with preserved cardiovascular function but showed lower aerobic capacity and less muscle strength than the control group. They also showed signs of postural orthostatic tachycardia and myopathy. The findings suggest cautious exercise adoption could be recommended to prevent further skeletal muscle deconditioning and health impairment in patients with PCC. ClinicalTrials.gov Identifier: NCT05445830.

Effect of outpatient cardiac rehabilitation on motor function and health-related quality of life in stroke survivors

BackgroundOutpatient cardiac rehabilitation (CR) is a promising tool for improving functional outcome in stroke survivors, however, evidence for improving emotional health is limited. We aimed to clarify the effects of outpatient CR following in-hospital stroke rehabilitation on health-related quality of life (HRQOL) and motor function. MethodsPatients with acute ischemic stroke or transient ischemic attack discharged directly home were recruited, and 128 patients who fulfilled criteria for insurance coverage of CR were divided into the CR (+) group (n = 46) and CR (-) group (n = 82). All patients underwent in-hospital stroke rehabilitation, and within 2 months after stroke onset, patients in the CR (+) group started a 3-month outpatient CR program of supervised sessions. Changes of motor function and HRQOL assessed by the short form-36 version 2 (SF-36) from discharge to 3 months post-discharge were compared between the two groups. ResultsTwenty-six patients in the CR (+) group completed the program and 66 patients in the CR (-) group were followed up at a 3-month examination. Least-square mean changes in 6-minute walk distance and isometric knee extension muscle strength were significantly higher in the CR (+) group than the CR (-) group (52.6 vs. 16.3 m; 10.1 vs. 3.50 kgf/kg). Improvement of HRQOL at 3 months was not observed in the CR (+) group. ConclusionsOutpatient CR following in-hospital stroke rehabilitation within 2 months after stroke onset improved exercise tolerance and functional strength but not HRQOL assessed by the SF-36 after completion of CR in the present cohort.

Reliability of belt-stabilized handheld or isokinetic dynamometer-based isometric knee-extensor strength-testing when seated with the toes of the contralateral nonexamined side off the floor.

[Purpose] To determine the intra-rater and inter-devices reliability of isometric knee-extensor muscle-strength-measurement. [Participants and Methods] The participants were 77 university students (50 males; 27 females) who underwent isometric knee-extension muscle-strength measurement twice with a belt-stabilized handheld dynamometer and isokinetic dynamometer. The intra-rater and inter-devices reliability was ascertained from measurements that were performed with the participant seated on the edge of the bed, the toes of the contralateral nonexamined side off the floor, and the trunk supported by the upper limb. [Results] In the overall, male, and female cohorts, the 95% confidence intervals of intra-rater reliabilities (1,1) in the belt-stabilized handheld and isokinetic dynamometers were 0.96-0.98, 0.92-0.97, and 0.81-0.96, 0.82-0.92, 0.73-0.90, and 0.78-0.95, respectively, and the inter-device 95% confidence intervals were 0.52-0.77, 0.28-0.69, and -0.03 to 0.63, respectively. Compared to the belt-stabilized handheld dynamometer group, the isokinetic dynamometer group had higher knee-extension muscle strength. [Conclusion] The intra-rater reliability was rated good-to-excellent and moderate-to-excellent for the belt-stabilized handheld and isokinetic dynamometers, respectively. The inter-devices reliability was poor, and isometric knee-extension muscle strength in the isokinetic dynamometer group was higher than that in the belt-stabilized handheld dynamometer group.

Impact of 14 Days of Bed Rest in Older Adults and an Exercise Countermeasure on Body Composition, Muscle Strength, and Cardiovascular Function: Canadian Space Agency Standard Measures

Introduction: Head-down bed rest (HDBR) has long been used as an analog to microgravity, and it also enables studying the changes occurring with aging. Exercise is the most effective countermeasure for the deleterious effects of inactivity. The aim of this study was to investigate the efficacy of an exercise countermeasure in healthy older participants on attenuating musculoskeletal deconditioning, cardiovascular fitness level, and muscle strength during 14 days of HDBR as part of the standard measures of the Canadian Space Agency. Methods: Twenty-three participants (12 males and 11 females), aged 55–65 years, were admitted for a 26-day inpatient stay at the McGill University Health Centre. After 5 days of baseline assessment tests, they underwent 14 days of continuous HDBR followed by 7 days of recovery with repeated tests. Participants were randomized to passive physiotherapy or an exercise countermeasure during the HDBR period consisting of 3 sessions per day of either high-intensity interval training (HIIT) or low-intensity cycling or strength exercises for the lower and upper body. Peak aerobic power (V̇O2peak) was determined using indirect calorimetry. Body composition was assessed by dual-energy X-ray absorptiometry, and several muscle group strengths were evaluated using an adjustable chair dynamometer. A vertical jump was used to assess whole-body power output, and a tilt test was used to measure cardiovascular and orthostatic challenges. Additionally, changes in various blood parameters were measured as well as the effects of exercise countermeasure on these measurements. Results: There were no differences at baseline in main characteristics between the control and exercise groups. The exercise group maintained V̇O2peak levels similar to baseline, whereas it decreased in the control group following 14 days of HDBR. Body weight significantly decreased in both groups. Total and leg lean masses decreased in both groups. However, total body fat mass decreased only in the exercise group. Isometric and isokinetic knee extension muscle strength were significantly reduced in both groups. Peak velocity, flight height, and flight time were significantly reduced in both groups with HDBR. Conclusion: In this first Canadian HDBR study in older adults, an exercise countermeasure helped maintain aerobic fitness and lean body mass without affecting the reduction of knee extension strength. However, it was ineffective in protecting against orthostatic intolerance. These results support HIIT as a promising approach to preserve astronaut health and functioning during space missions, and to prevent deconditioning as a result of hospitalization in older adults.

Knee Extensor Weakness Potently Predicts Postoperative Outcomes in Older Gastrointestinal Cancer Patients

ObjectivesMuscle weakness, assessed by grip strength, has been shown to predict postoperative mortality in older patients with cancer. Because lower extremity muscle strength well reflects physical performance, we examined whether lower knee extension muscle strength predicts postoperative mortality better than grip strength in older patients with gastrointestinal cancer. DesignProspective, observational study in a single institution. Setting and ParticipantsA total of 813 patients (79.0 ± 4.2 years, 66.5% male) aged 65 years or older with gastrointestinal cancer who underwent preoperative evaluation of grip strength and isometric knee extension muscle strength between April 2012 and April 2019 were included. MethodsThe study participants were prospectively followed up for postoperative mortality. Muscle weakness was defined as the lowest quartile of grip strength or knee extension strength (GS-muscle weakness and KS-muscle weakness, respectively). ResultsAmong the study participants, 176 patients died during a median follow-up of 716 days. In the Kaplan-Meier analysis, we found that patients with both GS-muscle weakness and KS-muscle weakness had a lower survival rate than those without muscle weakness. As expected, higher clinical stages and abdominal and thoracic surgeries compared with endoscopic surgery were associated with increased all-cause mortality. In addition, we found that KS-muscle weakness, but not GS-muscle weakness, was an independent prognostic factor after adjusting for sex, body mass index, cancer stage, surgical technique, and surgical site in the Cox proportional hazard model. Conclusions and ImplicationsIn older patients with gastrointestinal cancer, muscle weakness based on knee extension muscle strength can be a better predictor of postoperative prognosis than muscle weakness based on grip strength.

Not only muscle mass but also muscle quality is associated with knee extension muscle strength in patients with hip fractures

This study aimed to assess the relationship between isometric knee extension muscle strength on the operated or nonoperated sides and PhA in patients with hip fractures at approximately 6months postoperatively. This study was a cross-sectional study. Skeletal muscle index (SMI), PhA, knee extension muscle strength on the operated and nonoperated sides, and other physical function variables were assessed at approximately 6months postoperatively. To identify predictors of knee extension muscle strength on the operated and nonoperated sides, hierarchical multiple regression analysis was performed. A total of 90 patients with hip fractures were included (mean age, 80.1 ± 6.9years). SMI (0.45) and PhA on the operated side (0.27) were the significant associated factors extracted for isometric knee extension muscle strength on the operated side (standardized partial regression coefficients), independent of age, sex, and body mass index (BMI). Movement control during one-leg standing on the nonoperated side (0.26), SMI (0.32), and PhA on the nonoperated side (0.40) were the significant associated factors extracted for isometric knee extension muscle strength on the nonoperated side, independent of age, sex and BMI. Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures at approximately 6months postoperatively was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

The 30-s chair stand test can be a useful tool for screening sarcopenia in elderly Japanese participants

BackgroundLow muscle strength has been focused on as an essential characteristic of sarcopenia, and the 30-s chair stand test (CS-30) could be a particularly useful test for assessing muscle strength. While it is speculated to be a beneficial tool for the assessment of sarcopenia, this remains to be verified. In this study, we examined the reliability and optimal diagnostic score of the CS-30 for assessing sarcopenia in elderly Japanese participants.MethodsThis cross-sectional study included 678 participants (443 females and 235 males) who underwent the test for sarcopenia as per the Asian Working Group for Sarcopenia (AWGS) 2019, the CS-30 test, and the isometric knee-extension muscle strength test. ROC analysis was used to estimate the optimal CS-30 scores at which sarcopenia was detected.ResultsCS-30 scores were positively associated with sarcopenia (OR: 0.88; 95% CI:0.82–0.93). The AUC of the CS-30 for sarcopenia definition were 0.84 (p < 0.001) for females and 0.80 (p < 0.001) for males. The optimal number of stands in the CS-30 that predicted sarcopenia was 15 for females (sensitivity, 76.4%; specificity, 76.8%) and 17 for males (sensitivity, 75.0%; specificity, 71.7%).ConclusionsThe CS-30 was found to be a reliable test for sarcopenia screening in the elderly Japanese population.

Impaired knee extension muscle strength in adolescents but not in children with Fontan circulation.

Impaired isometric muscle strength was previously reported in adults with Fontan circulation. However, it is unclear if this impairment is present in children and adolescents with Fontan circulation. We investigated isometric muscle strength of the lower limb in patients (6-18 years) with Fontan circulation in comparison with healthy controls. In this cross-sectional study, 43 patients (6-18 years) with Fontan circulation and 43 age- and sex-matched controls were included. Isometric knee extension and plantar flexion muscle strength were assessed using dynamometry (Newton, N). Lean mass of the legs was assessed with dual-energy X-ray absorptiometry. Analyses were performed on group level (n = 43), and for subgroups that included children aged 6-12 years (n = 18) and adolescents aged 13-18 years (n = 25). On group level, the patients with Fontan circulation had impaired isometric knee extension strength in comparison with the controls (p = 0.03). In subgroup analyses, impaired isometric knee extension strength was present in the adolescents (p = 0.009) but not in the children groups. For plantar flexion, there was no difference between patients and controls. There was no difference in lean mass between patients and controls (9.6 ± 4.3 kg vs. 10.8 ± 5.6 kg, p = 0.31). However, the lean mass was highly correlated to isometric knee extension strength (patients r = 0.89, controls r = 0.96, p < 0.001) and isometric plantar flexion strength (patients r = 0.7, controls r = 0.81, p < 0.001). The finding of impaired isometric knee extension muscle strength in adolescents (13-18 years) with Fontan circulation and no corresponding impairment in the children group (6-12 years) could imply that isometric muscle strength gets more impaired with age.

Validity and reliability of isometric knee extension muscle strength measurements using a belt-stabilized hand-held dynamometer: a comparison with the measurement using an isokinetic dynamometer in a sitting posture.

[Purpose] This study aimed to determine the validity and reliability of isometric knee extension muscle strength measurements using a belt-stabilized hand-held dynamometer compared to that using an isokinetic dynamometer with the participant in a sitting posture. [Participants and Methods] Forty-two university students participated. The isometric knee extension muscle strength was measured using a hand-held dynamometer and an isokinetic dynamometer. For both measurements, the participants were in the similar sitting posture. The sitting posture maintained trunk stability, with the hands on the bed, and the non-measurement-side toe touching the floor or table. The intra-class correlation coefficient and the relevance were verified. [Results] Intra-rater correlation coefficient (1, 1) of the two measurements was ≥0.75. A significant difference was found in the measurement value between males and females. No significant difference was found between the measurements value of the two devices. A significant positive correlation was found in the measurement value of two devices in the male participants. [Conclusion] When compared to the standard method of isometric knee extension muscle strength measurements using an isokinetic dynamometer with the participant in the sitting posture, measurements using the belt-stabilized hand-held dynamometer were considered valid and highly reliable in the male participants.

Inter-rater reliability of the devised isometric knee extension muscle strength measurement method

Inter-rater reliability of the devised isometric knee extension muscle strength measurement method

Preliminary effect and feasibility of physiotherapy with strength training and protein-rich nutritional supplement in combination with anabolic steroids in cross-continuum rehabilitation of patients with hip fracture: protocol for a blinded randomized controlled pilot trial (HIP-SAP1 trial)

BackgroundA 2014 Cochrane review evaluating the effect of anabolic steroids after hip fracture concluded that the quality of the studies was insufficient to draw conclusions on the effects and recommended further high-quality trials in the field. Therefore, the aim of this pilot trial is to determine the preliminary effect and feasibility of a 12-week multimodal intervention consisting of physiotherapy (with strength training), protein-rich nutritional supplement and anabolic steroid on knee-extension muscle strength and function 14 weeks after hip fracture surgery.MethodsWe plan to conduct a randomized, placebo-controlled pilot trial with 48 patients operated for acute hip fracture. The patients are randomized (1:1) to either (1) physiotherapy with protein-rich nutritional supplement plus anabolic steroid or (2) physiotherapy with protein-rich nutritional supplement plus placebo. Outcome assessments will be carried out blinded at baseline (3–10 days after surgery) and at 14 weeks after entering the trial. Primary outcome is the change from baseline to follow-up in maximal isometric knee-extension muscle strength in the fractured limb. Secondary outcomes are physical performance test, patient-reported outcomes, and measures of body composition.DiscussionIf the trial is found feasible and the results show an indication of anabolic steroid being a relevant addition to further enhance the recovery of muscle strength and function in an enhanced recovery after surgery program, this trial will constitute the basis of a larger confirmatory trial.Trial registrationClinicalTrials.gov, NCT03545347. Preregistered on 4 June 2018.

Isometric knee muscle strength measurement using a belt-stabilized hand-held dynamometer and an isokinetic dynamometer with and without trunk fixation: investigation of agreement of measurement values and factors influencing measurement.

[Purpose] The purpose of this study was to examine the agreement between the values obtained by using a hand-held dynamometer with a belt (belt-HHD) and an isokinetic dynamometer (IKD) for the measurement of isometric knee flexion and extension muscle strength. We also studied the factors influencing the measurement. [Participants and Methods] Overall, 26 healthy young adults (16 males, 10 females) participated in the study; the mean age was 21 years. Knee flexion and extension muscle strength were measured by three methods: 1) belt-HHD, 2) conventional IKD with the participant sitting on an attached chair (conv-IKD), and 3) modified IKD with the participant sitting on the same mat table as HHD (mod-IKD). [Results] In the measurement of knee extension, mod-IKD and conv-IKD showed a fixed bias and a proportional bias, conv-IKD and belt-HHD showed a fixed bias, and belt-HHD and mod-IKD showed a fixed bias. In the measurement knee flexion, conv-IKD and mod-IKD showed a proportional bias, belt-HHD and conv-IDK showed a fixed bias, and mod-IKD and belt-HHD showed a fixed bias. In each combination, the measured values were larger in the latter due to errors. However, the types and values of errors differed when analysis was conducted based on gender. [Conclusion] In order to increase the agreement between the values, it is necessary to revise the fixing method of the trunk, and the fixing method of the belt and the sensor pad in belt-HHD.

The baseline speed of 10-m gait predicts ambulatory discharge for hospitalized frail elderly after DOPPO rehabilitation.

The discharge of elderly patients from hospital on the basis of their independent gait program (DOPPO) is a new rehabilitation strategy for physically frail hospitalized elderly that aims to recover independent gait and to achieve ambulatory discharge. We retrospectively investigated baseline determinants of physical measures associated closely with the 6-min walking distance (6MWD) after DOPPO. Participants were 137 consecutive elderly inpatients, irrespective of the causative disease (mean age: 82±7 years; 76 women), who had a Short Physical Performance Battery (SPPB) score of less than 12 and low independent walking capacity. The rehabilitation comprised muscle stretching, muscle strengthening, balance training, and endurance exercise, including walking. The exercises were gradually increased until the goal of ambulatory discharge was attained. The SPPB, isometric knee-extension muscle strength (IKEMS), functional reach test (FRT), one-leg stance time (OLST), and the 10-m gait speed (TMGS) were measured, before and after the DOPPO intervention, and their association with the 6MWD was evaluated. All participants achieved ambulatory discharge, requiring on average 35±19 hospital days and 32±18 h of rehabilitation. The SPPB, IKEMS, FRT, OLST, and TMGS improved. The SPPB scores increased from 7.1 at baseline to 9.2 at discharge. Eighty-eight patients completed the 6MWD. The SPPB, IKEMS, FRT, OLST, and TMGS were strongly associated with the 6MWD. Only the baseline TMGS and SPPB predicted the 6MWD, with a cut-off TMGS value of 0.84 m/s providing the best prediction of achieving a distance of more than 300 m on the 6MWD. Thus, the baseline TMGS is the best prediction of the ambulatory outcome after the present DOPPO rehabilitation.

Association Between the Functional Independence and Difficulty Scale and Physical Functions in Community-Dwelling Japanese Older Adults Using Long-term Care Services.

The Functional Independence and Difficulty Scale (FIDS), a newly developed basic activities of daily living (BADL) assessment tool, assesses both independence and subjective difficulty of BADL performance. This patient-reported outcome measure has been shown to have acceptable internal consistency, concurrent validity, and reliability. However, little is known about the relationship between FIDS and objective measures of physical function among older Japanese adults using long-term care insurance services. This study aimed to reveal the relationship between FIDS and physical functions and to examine the concurrent validity of FIDS against physical functions. Participants of this cross-sectional, correlational research study included community-dwelling Japanese adults aged 65 years or older and certified as long-term care insurance service users with musculoskeletal disease, internal disease, cerebrovascular diseases without observable motor paralysis, and others. Data on physical functions, including muscle strength (grip strength and isometric knee extension muscle strength [IKEMS]), flexibility (range of motion [ROM] of hip flexion and knee flexion), balance (Modified Functional Reach Test [M-FRT]) and gait performance (timed 2.4-m walk), and BADL performance assessed by FIDS, were obtained. Associations between FIDS scores and physical functions were determined by Spearman correlation coefficient and partial correlations after controlling for subject age and sex. Data were collected on 53 participants (mean age = 81.9 years; 62.3% women). Spearman partial correlation coefficients controlled for sex and age between FIDS score and grip strength, IKEMS, ROM of hip flexion, ROM of knee flexion, M-FRT, and timed 2.4-m walk were 0.47 (P = .001), 0.44 (P = .001), 0.29 (P = .04), -0.05 (P = .73), 0.51 (P < .001), and -0.64 (P < .001), respectively. The strength of association was moderate for the M-FRT and 2.4-m walk and was low for grip strength and IKEMS. However, ROM of the knee showed no significant association and hip flexion had negligible association with FIDS. The FIDS, a patient-reported BADL assessment tool, mainly reflected balance and gait performance and had concurrent validity as an objective measure of balance and gait performance.

Key function for obstacle crossing in hemiplegic persons with varied degrees of spasticity.

[Purpose] To evaluate various key functions related to obstacle crossing motions in hemiplegic people based on the paralysis degree. [Subjects and Methods] Thirty-seven patients with maintenance-stage hemiplegia who could independently ambulate outdoors were included. Subjects’ crossing movements were measured using obstacles with heights of 10%, 20%, and 30% of the trochanter length. The relationship among maximal crossing height and isometric knee extension muscle strength, one leg standing time, Trunk Impairment Scale score, disease duration, and subject age was examined, as was the target variable of maximum crossing height and the top four measurement items, to determine the explanatory variables. The participants were grouped based on Brunnstrom Recovery Stages III–IV (severe spasticity) and V–VI (mild spasticity). [Results] The explanatory variables were the Trunk Impairment Scale in the severe spasticity group and unaffected side-knee extension muscle strength in the mild spasticity group (contribution rates: 75.6% and 21.0%, respectively). [Conclusion] Trunk function in the severe spasticity group majorly contributed to crossing obstacles. Furthermore, knee extension muscle strength on the unaffected side in the mild spasticity group moderately contributed to crossing obstacles. Selecting and implementing a physical therapy routine that is aimed at improving function, depending on the severity of paralysis, is necessary.

Effects of trunk stability on isometric knee extension muscle strength measurement while sitting.

[Purpose] This study aimed to investigate the effect of trunk stability on isometric knee extension muscle strength measurement while sitting by performing simultaneous measurements with a handheld dynamometer (HHD) and an isokinetic dynamometer (IKD) in the same seated condition. [Subjects and Methods] The subjects were 30 healthy volunteers. Isometric knee extension muscle strength was simultaneously measured with a HHD and an IKD by using an IKD-specific chair. The measurement was performed twice. Measurement instrument variables and the number of measurements were examined by using the analysis of variance and correlation tests. [Results] The measurement instrument variables and the number of measurements were not significantly different. The correlation coefficients between the HHD and IKD measurements were ≥0.96. [Conclusion] Isometric knee extension muscle strength measurement using the HHD in the sitting position resulted in a lower value than that using the IKD, presumably because of the effect of trunk stability on the measurement. In the same seated posture with trunk stability, no significant difference in measurement values was observed between the HHD and IKD. The present findings suggest that trunk stability while seated during isometric knee extension muscle strength measurement influenced the HHD measurement.

Does the Q - H index show a stronger relationship than the H:Q ratio in regard to knee pain during daily activities in patients with knee osteoarthritis?

[Purpose] The purpose of this study was to elucidate the relationship between knee muscle strength and knee pain in activities of daily living, based on consideration of the difference between extension and flexion strength (Q − H) and the hamstring:quadriceps (H:Q) ratio in patients with knee osteoarthritis. [Subjects and Methods] The participants were 78 females with knee osteoarthritis, and a total of 133 knees that had not been treated surgically were the targets of this research. The legs were divided according to dominance. Isometric knee extension and flexion muscle strength and knee pain during activities of daily living were measured. The H:Q ratio (flexion/extension muscle strength) and the difference between extension and flexion strength, (extension muscle strength/weight) minus (flexion muscle strength/weight), that is, Q − H, were calculated. The correlation between these indices and the knee pain score during activities of daily living was investigated. [Results] Greater knee pain during activities of daily living was related to lower knee extension muscle strength and Q − H in both the dominant and nondominant legs. Knee flexion muscle strength and the H:Q ratio were not significantly correlated with knee pain during any activities of daily living. [Conclusion] Knee extension muscle strength and Q − H were found to be significantly correlated with knee pain during activities of daily living, whereas the H:Q ratio was not.

Reliability of isometric knee extension muscle strength measurements made by a hand-held dynamometer and a belt: a comparison of two types of device.

[Purpose] The purpose of the present study was to compare the reliability of 2 hand-held dynamometers (HHD-1, 2) with different designs, by performing isometric knee muscle extension measurements two times each. [Subjects] The subjects were 40 young healthy adults. [Methods] The reliability of the measurements was examined using Bland-Altman analysis. [Results] Bland-Altman analysis found a fixed bias in measurements made by HHD-1 with an average limits of agreement (LOA) value of −2.1 kgf. For HHD-2, only random errors were detected, and the minimal detectable change (MDC) was 11.4 kgf. Fixed biases were observed between the two devices with an average LOA value of 2.2 kgf. When the bodyweight ratio was used, fixed biases were observed in measurements made by both devices, and the average value of LOA was −0.03 kgf/kg. The comparison of the two devices revealed only random errors, and MDC was 0.22 kgf/kg. [Conclusion] For HHD measurements using these two devices, the appropriate number of measurements is two times, and comparison of measurement values between the two devices should be avoided.