Knee Extension Strength Measurements Research Articles

Poster 322: Blood Flow Restriction after ACL Reconstruction Does Not Accelerate Quadriceps Strengthening

Objectives: The use of blood flow restriction (BFR) therapy has gained popularity as an adjunct rehabilitation technique following anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to longitudinally evaluate the impact that BFR has on quadriceps strength following ACLR with quadriceps tendon (QT) autograft in comparison to traditional rehabilitation protocols. Methods: Patients undergoing primary ACLR with QT autograft at a single institution were retrospectively reviewed. Included patients had a minimum of two isometric strength testing sessions via electromechanical dynamometer (Biodex). Obtained strength measures included peak knee extension torque of the operative extremity and knee extension ratio (KER), in which the ratio of peak knee extension torque of the operative extremity and nonoperative extremity were compared. Strength measures were compared between patients that received BFR during postoperative rehabilitation and patients that underwent traditional rehabilitation without BFR for up to three strength measurement sessions. Demographic and surgical factors including patient age at surgery, sex, BMI, level of competition, time from injury to surgery, time from surgery to strength measurement session, use of regional anesthesia, tourniquet time, and concomitant surgery were collected. Two group comparisons of continuous and categorical variables were analyzed by using Mann-Whitney U and chi-squared test, respectively. Statistical significance was set at 0.05. Results: A total of 45 patients (26 female) in the BFR group and 36 patients (13 female) in the traditional rehabilitation group met inclusion criteria. Mean age of the entire cohort was 19.5 years. There were no statistically significant differences among demographic or surgical factors between BFR and traditional cohorts. Of patients receiving BFR therapy, the mean number of BFR treatments was 18 from surgery to first strength measurement, 8 between first and second strength measurements, and 9 between the second and third strength measurements. Peak knee extension torque was lower for the BFR (96 Nm) group than traditional (111 Nm) group at the first strength measurement session (p=0.03) but was similar between groups at the second (118 Nm vs 134 Nm, p=0.1) and third (138 Nm vs 130 Nm, p =0.39) strength measurement sessions. There was no difference among BFR and traditional groups in the change of knee extension peak torque or change in KER between testing sessions. KER was lower at the second strength measurement in the BFR group (0.81) compared to the traditional group (0.90, p=0.02), though no differences existed at the first or third strength measurements. Conclusions: Sequential knee extension strength measurements following ACLR in a young patient cohort demonstrated improvements irrespective of BFR use. There were no differences in the change of strength measures between testing sessions when comparing BFR and traditional rehabilitation groups. Both groups demonstrated similar strength improvements over time, and BFR did not accelerate strength gains compared to traditional rehabilitation. However, as the BFR cohort had lower starting yet similar final strength measurements compared to the traditional rehabilitation cohort, a role for BFR over the long term in at risk patients cannot be excluded.

Knee Extension Strength Measures Indicating Probable Sarcopenia Is Associated with Health-Related Outcomes and a Strong Predictor of 1-Year Mortality in Patients Following Hip Fracture Surgery.

To examine if knee-extension strength (KES) measures indicating probable sarcopenia are associated with health-related outcomes and if KES and hand grip strength (HGS) measures are associated with 1-year mortality after hip fracture. Two groups of older patients with hip fracture had either HGS (n = 32) or KES (n = 150) assessed during their acute hospital stay. Cut-points for HGS (<27 kg for men and <16 kg for women), and cut-points for maximal isometric KES (non-fractured limb), being the lowest sex-specific quintile (<23.64 kg for men and <15.24 kg for women), were used to examine association with health-related outcomes and 1-year mortality. Overall, 1-year mortality was 12.6% in the two strength groups, of which 47% (HGS) and 46% (KES) respectively, were classified as probable sarcopenia. Probable sarcopenia patients (KES) had lower prefracture function, performed poorly in mobility measures and expressed a greater concern of falling compared to their stronger counterparts. Hazard ratio for 1-year mortality was 2.7 (95%CI = 0.49–14.7, p = 0.3) for HGS and 9.8 (95%CI = 2.2–43.0, p = 0.002) for KES for probable sarcopenia patients compared to those not. Sex-specific KES measures indicating sarcopenia is associated with health-related outcomes and a strong predictor of 1-year mortality after hip fracture.

Isometric Strength Measures are Superior to the Timed Up and Go Test for Fall Prediction in Older Adults: Results from a Prospective Cohort Study.

BackgroundIsometric strength measures and timed up and go (TUG) tests are both recognized as valuable tools for fall prediction in older adults. However, results from direct comparison of these two tests are lacking. We aimed to assess the potential of isometric strength measures and the different modalities of the TUG test to detect individuals at risk of falling.MethodsThis is a prospective cohort study including 24 community-dwelling older adults (≥65 years, 19 females, 88±7 years). Participants performed three variations of the TUG test (standard, counting and holding a full cup) and three isometric strength tests (handgrip, knee extension and hip flexion) at several time points (at baseline and every ~6 weeks) during a one-year follow-up. The association between these tests and the incidence of falls during the follow-up was assessed.ResultsTwelve participants out of 24 participants experienced falls during the follow-up. Fallers showed a significantly lower handgrip strength (−5.7 kg, 95% confidence interval: −10.4 to −1.1, p=0.019) and knee extension strength (−4.9 kg, −9.6 to −0.2, p=0.042) at follow-up, while no significant differences were found for any TUG variation.ConclusionsHandgrip and knee extension strength measures – particularly when assessed regularly over time – have the potential to serve as a simple and easy tool for detecting individuals at risk of falling as compared to functional mobility measures (ie, TUG test).

Tests of muscle function and health related quality of life in healthy older adults in Sweden

BACKGROUND: Life expectancy among older adults has dramatically increased and they are one of the fastest growing populations worldwide. Maintaining quality of life and the ability to live independently are often of greater importance than overall life expectancy. OBJECTIVE: To present reference values for tests of muscle function, and to study the relationship to a commonly used tool of generic health related quality of life (HRQL) in older Swedish adults. METHODS: The study consisted of 192 individuals (105 women) aged between 65 and 80. The tests included hand grip and isometric knee extension strength measurements, the standing heel rise test and a 30 m walking test. Health-related quality of life (HRQOL) was evaluated using the SF-36. RESULTS: Reference values for the measured parameters are presented. There were high correlations (n= 192) between handgrip and leg extension strength (r= 0.72–0.75; p&lt; 0.01). The walking test’s self-selected speed demonstrated the strongest correlation with the physical component summary of the SF-36 (r= 0.57; p&lt; 0.01) and with maximal speed, moderate correlations were demonstrated with muscle strength (r= 0.43–0.56; p&lt; 0.01) and the heel rise test (r= 0.45; p&lt; 0.01). CONCLUSIONS: This study presents reference values for simple tests of muscle function which are relatively easy to perform, used in a Swedish clinical setting performing screening for older adults.

SEX DIFFERENCES IN QUADRICEPS STRENGTH AMONG ADOLESCENTS WITHIN 1 YEAR OF ACL RECONSTRUCTION

Background Female patients with ACLR are 40% less likely to return to preinjury levels of sport after subsequent ACLR when compared to their male counterparts. Additionally, 24-30% of young female athletes who do return to sport will go on to experience a second ACL injury to the ipsilateral or contralateral knee within 2 years of ACLR. Despite these findings, sex-based differences in clinical outcomes following ACLR are not currently well understood within the adolescent population. Involved limb knee extension weakness, contralateral limb knee extension weakness, and between limb strength asymmetry persist months to years following ACLR among adolescent patients. Improvements in unilateral and symmetry-based measures of knee extension strength during and after the rehabilitation process have been linked to improved patient-reported knee related function, lower extremity functional performance, and decreased risk of subsequent ACL injury among individuals with recent ACLR. Currently, there is a lack of evidence describing the role that sex plays in persistent quadriceps weakness. Therefore, the purpose of this study was to investigate the effects of patient sex on unilateral and symmetry-based measures of knee extension strength, and patient-reported knee function among adolescent individuals with ACL reconstruction (ACLR) within the first year after surgery. Methods: Fifty-two male participants (age = 16.8±1.3 years, BMI = 25.6±5.6 kg/m2, time since surgery = 6.3±1.4 months) and 66 female participants (age = 16.7±1.4 years, BMI = 23.9±3.9kg/m2, time since surgery = 6.8±1.7 months) with unilateral ACLR, 4-12 months prior to enrollment were recruited for this multi-site cross-sectional study. Participants completed bilateral knee extension maximal voluntary isometric contraction (MVIC) torque assessments using a multimodal dynamometer with continuous verbal encouragement from the tester and visual feedback on a nearby monitor. Peak knee extension MVIC torque was identified for each of 3 trials and was normalized to body mass (Nm/kg). Limb symmetry indices were also calculated by dividing the MVIC torque obtained for the involved limb by the MVIC torque obtained for the contralateral limb. Participants also completed the International Knee Documentation Committee (IKDC) Subjective Knee Form to assess patient-reported knee function. Sex-based comparisons of quadriceps strength outcomes and IKDC score were made using separate ANCOVAs where time since surgery was utilized as a covariate. Cohen’s d effect sizes and 95% confidence intervals (CI95) were calculated to assess the magnitude of sex difference for all outcome measures. Odds ratios and CI95 were also calculated to assess the odds of an adolescent female achieving clinical threshold for acceptable involved limb quadriceps strength (MVIC = 3.0 Nm/kg), quadriceps limb symmetry (LSI = 90.0%), and patient-reported knee function (IKDC = 90.0). Results: The involved limb (male = 2.08±0.95 Nm/kg, female = 1.69±0.63 Nm/kg, p = 0.01, d = -0.50, CI95 = -0.13 to -0.87) and contralateral limbs (male = 2.75±0.75 Nm/kg, female = 2.31±0.64 Nm/kg, p = 0.001, d = -0.64, CI95 = -0.26 to -1.01) of male participants were stronger when compared to female participants but limb symmetry (male = 74.7±22.6%, female = 74.7±24.6%, p = 0.95, d = 0.00, CI95 = 0.36 to -0.36) and IKDC score (male = 84.4±16.1, female = 79.4±13.7, p = 0.08, d = -0.34, CI95 = 0.03 to -0.71) was not significantly different between the sexes. Male participants were 5.66 times (CI95 = 1.46 to 21.87) more likely to meet the clinical threshold for acceptable involved limb quadriceps strength and 3.52 times (CI95 = 1.54 to 8.05) more likely to report acceptable knee related function. The likelihood of achieving clinically acceptable limb symmetry was not significantly different between the sexes (OR = 1.17, CI95 = 0.48 to 2.83). Conclusion/Significance: Adolescent female patients may experience significantly worse involved limb and contralateral quadriceps weakness when compared to adolescent male patients despite displaying equally poor limb symmetry and patient-reported knee function during the first 12 month following surgery. Given the importance of involved limb quadriceps strength as a predictor of patient-reported function and movement quality, clinicians should incorporate patient education regarding the importance of quadriceps function and recommend progressive lower extremity loading when implementing patient-centered rehabilitation plans that promote safe return to healthy levels of physical activity following ACLR.

Demographic and surgical factors affect quadriceps strength after ACL reconstruction.

To investigate the effects of graft source, time since surgery, age, and sex on unilateral and symmetry-based measures of knee extension strength among individuals with ACL reconstruction (ACLR). Three hundred and eight individuals aged 13-40years old with primary, unilateral ACLR in the last 60months were enrolled in this multi-site clinical measurement study. Participants completed bilateral knee extension maximal voluntary isometric contraction (MVIC) torque assessments which were normalized to body mass (Nm/kg) and limb symmetry indices (LSI) were calculated. The effects of graft source (patellar tendon autograft; hamstring tendon autograft), time since surgery (≤ 12months; >12 mo.), age (≤ 18 years; >18years), and sex were evaluated using separate ANCOVAs. A significant interaction was present between time since surgery and graft source for LSI (P = 0.01) as participants with patellar tendon autografts ≤ 12months post-ACLR experienced the greatest asymmetry (LSI = 69.2 ± 24.5%). Significant interactions were present between time since surgery and sex for involved limb (P = 0.01) and uninvolved limb MVIC torque (P = 0.05) with females ≤ 12months post-ACLR being weakest (involved MVIC = 1.81 ± 0.70Nm/kg; uninvolved MVIC = 2.40 ± 0.68Nm/kg). Participants ≤ 18-year-old displayed weaker involved limb (P < 0.001) and contralateral limb (P < 0.001) MVIC torque as compared to participants > 18-year-old during the first year after ACLR. Graft source, sex, age, and time since surgery effect quadriceps strength and symmetry after ACLR. Surgical and demographic factors should be considered when developing treatment approaches to optimize quadriceps function prior to re-integration into pre-injury levels of physical activity. IV.

Knee extension strength measurements should be considered as part of the comprehensive geriatric assessment

BackgroundComprehensive geriatric assessment (CGA) generally includes handgrip strength (HGS) as a measure of overall muscle strength that is associated with various health characteristics in geriatric outpatients. Whether this is also true for knee extension strength (KES) is yet unknown. This study aims to compare the associations between health characteristics from the CGA with both HGS and KES in geriatric outpatients.MethodsData were retrieved from a cross-sectional study. A total of 163 community-dwelling older adults referred to a geriatric outpatient clinic of a middle-sized teaching hospital were included. Health characteristics included physical, nutritional, social, psychological, diseases, cognitive, and behavioural factors. HGS and KES were assessed three times for each limb and the best performance was used for analysis. Sex-specific z-scores of HGS and KES were used to allow comparison of effect estimates. Associations between health characteristics with standardized HGS and KES were analysed with linear regression adjusted for age, sex and further adjustment for standardized KES (for model of HGS) or standardized HGS (for model of KES).ResultsPhysical, nutritional and psychological health characteristics were positively associated with both HGS and KES after adjustment for age and sex, with overall stronger associations with KES compared to HGS. All significant associations with HGS were lost after further adjustment for KES; significant associations with KES remained after further adjustment for HGS, except for nutritional characteristics.ConclusionsStronger associations of health characteristics with KES compared to HGS indicate its additional value and therefore inclusion of KES in the CGA is recommended.

Validity of maximal isometric knee extension strength measurements obtained via belt-stabilized hand-held dynamometry in healthy adults.

[Purpose] To determine the validity of knee extension muscle strength measurements using belt-stabilized hand-held dynamometry with and without body stabilization compared with the gold standard isokinetic dynamometry in healthy adults. [Subjects and Methods] Twenty-nine healthy adults (mean age, 21.3 years) were included. Study parameters involved right side measurements of maximal isometric knee extension strength obtained using belt-stabilized hand-held dynamometry with and without body stabilization and the gold standard. Measurements were performed in all subjects. [Results] A moderate correlation and fixed bias were found between measurements obtained using belt-stabilized hand-held dynamometry with body stabilization and the gold standard. No significant correlation and proportional bias were found between measurements obtained using belt-stabilized hand-held dynamometry without body stabilization and the gold standard. The strength identified using belt-stabilized hand-held dynamometry with body stabilization may not be commensurate with the maximum strength individuals can generate; however, it reflects such strength. In contrast, the strength identified using belt-stabilized hand-held dynamometry without body stabilization does not reflect the maximum strength. Therefore, a chair should be used to stabilize the body when performing measurements of maximal isometric knee extension strength using belt-stabilized hand-held dynamometry in healthy adults. [Conclusion] Belt-stabilized hand-held dynamometry with body stabilization is more convenient than the gold standard in clinical settings.

Validity of maximal isometric knee extension strength measurements obtained with a belt-stabilized hand-held dynamometer method in healthy adults

Validity of maximal isometric knee extension strength measurements obtained with a belt-stabilized hand-held dynamometer method in healthy adults

Reliability of Isometric Knee Extension Muscle Strength Measurements of Healthy Elderly Subjects Made with a Hand-held Dynamometer and a Belt.

[Purpose] The purpose of this study was to examine the reliability of three isometric knee extension strength measurements (IKE) made with a hand-held dynamometer (HHD) and a belt of healthy elderly living in the community as subjects. [Subjects] The subject cohort consisted of 186 healthy elderly people, aged 65 to 79 years, living in local communities. [Methods] IKE of the leg subjects used to kick a ball was measured. IKE of each subject was measured three times using an HHD-belt at intervals of 30 seconds. The reliability of the larger of the first two measurements (LV2) as well as the third measurement (3V) was investigated. [Results] The intraclass correlation coefficients [ICC (1, 1)] for LV2 and 3V were 0.955. Bland-Altman analysis showed a fixed bias, and the limits of agreement ranged from −5.6 to 4.6. [Conclusion] The ICC results show that the test-retest reproducibility of IKE measurements of healthy elderly subjects using an HHD-belt is high. However, Bland-Altman analysis showed a fixed bias, suggesting the need for three measurements.

Muscle Strength and Body Composition Are Clinical Indicators of Osteoporosis

We examined the role of muscle strength, lean tissue distribution, and overall body composition as indicators of osteoporosis (OP) in a pooled sample of 979 Finnish postmenopausal women (mean age 68.1 years) from the Kuopio Osteoporosis Risk Factor and Prevention study. Bone mineral density (BMD) at the femoral neck (FN) and total body composition were assessed by dual-energy X-ray absorptiometry scans. The women (n = 979) were divided into three groups according to WHO criteria, based on FN BMD T score: normal (n = 474), osteopenia (n = 468), and OP (n = 37). Soft tissue proportions, fat mass index (FMI, fat/height²), lean mass index (LMI, lean/height²), and appendicular skeletal muscle mass (ASM, (arms + legs)/height²) were calculated. Handgrip and knee extension strength measurements were made. OP subjects had significantly smaller LMI (p = 0.001), ASM (p = 0.001), grip strength (p < 0.0001), and knee extension strength (p < 0.05) but not FMI (p > 0.05) compared to other subjects. Grip and knee extension strength were 19 and 16 % weaker in OP women compared to others, respectively. The area under the receiver operating characteristic curve was 69 % for grip and 71 % for knee extension strength. In tissue proportions only LMI showed predictive power (63 %, p = 0.016). An overall linear association of LMI (R² = 0.007, p = 0.01) and FMI (R² = 0.028, p < 0.001) with FN BMD remained significant. In the multivariate model, after adjusting for age, grip strength, leg extension strength, FMI, LMI, number of medications, alcohol consumption, current smoking, dietary calcium intake, and hormone therapy, grip strength (adjusted OR = 0.899, 95 % CI 0.84-0.97, p < 0.01), leg extension strength (OR = 0.998, 95 % CI 0.99-1, p < 0.05), and years of hormone therapy (OR = 0.905, 95 % CI 0.82-1, p < 0.05) remained as significant determinants of OP. Muscle strength tests, especially grip strength, serve as an independent and useful tool for postmenopausal OP risk assessment. In addition, lean mass contributes to OP in this age group. Muscle strength and lean mass should be considered separately since both are independently associated with postmenopausal BMD.

Are Hand-Grip and Knee Extension Strength Reflective of a Common Construct?

Grip and knee extension strength have each been used to characterize muscle strength. Whether grip and knee extension strength reflect a common construct was investigated. Bilateral isometric grip and knee extension strength measures obtained by dynamometry were retrieved from the records of 34 adults who were at least 60 years of age (M = 80.2 yr., SD = 8.1) and had diverse non-focal diagnoses or problems. Relations between measurements were examined using Pearson correlations, Cronbach's alpha, and factor analysis. Pearson correlations (r = .55 to .89), Cronbach's alpha (.88), and factor analysis (loadings .85 to .91) all suggest that grip and knee extension strength reflect a common construct. Either grip or knee extension strength, therefore, may be adequate to characterize limb muscle strength in older adults who are receiving physical therapy for diverse non-focal diagnoses or problems. Nevertheless, the measurement of grip strength may be preferred because it is easier.

Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study

Objective: To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty. Design: A prospective, single-blinded, randomized, cross-over study. Setting: A fast-track orthopaedic arthroplasty unit at a university hospital. Participants: Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty. Interventions: The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30 minutes of elbow icing (control treatment). The order of treatments was randomized. Main outcome measures: Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2–5 minutes before and 2–5 minutes after both treatments by an assessor blinded for active or control treatment. Results: The change in knee extension strength associated with knee icing was not significantly different from that of elbow icing (knee icing change (mean (1 SD)) –0.01 (0.07) Nm/kg, elbow icing change –0.02 (0.07) Nm/kg, P = 0.493). Likewise, the changes in knee pain at rest (P = 0.475), or knee pain during the knee extension strength measurements (P = 0.422) were not different between treatments. Conclusions: In contrast to observations in experimental knee effusion models and inflamed knee joints, knee joint icing for 30 minutes shortly after total knee arthroplasty had no acute effect on knee extension strength or knee pain.

Alternatives for measuring knee extension strength of the elderly at home.

To examine the construct validity of three measures of knee extension strength obtained from elderly individuals. Retrospective and cross-sectional. Home care. Forty-one consecutively treated patients (mean age 79.2 years). Knee extension strength was measured using manual muscle testing, hand-held dynamometry, and the sit-to-stand test. Convergent construct validity was supported by the significant correlations between the measures (rs = 0.578-0.702). Discriminant construct validity was confirmed by the finding of significant differences in the manual muscle test scores and in the hand-held dynamometer measures of patients who were unable versus able to stand from a chair without the upper extremities or help. The sensitivity of the two measures for discriminating between patients able versus unable to stand from a chair was 90.9% for manual testing and 68.2% for dynamometry. The specificity was 78.9% for manual testing and 94.7% for dynamometry. The results of this study show that the three measures employed to characterize knee extension strength are valid when employed with elderly patients in a home care setting.

Prediction of Walking Performance Six Months after Kidney Transplantation.

This study investigated the ability of 17 variables measured pretransplant to predict gait speed post transplant. Twenty-one renal transplant patients participated. Their age, height, weight, gender, diabetic status, knee extension force, grip force, sit to stand performance, standing balance, and gait speed (comfortable and maximum) were documented before transplant. Gait speed was measured again six months post transplant. Ten of the pretransplant variables were correlated significantly with both comfortable and maximum gait speed six months post transplant. Four additional pretransplant variables were correlated significantly with maximum gait speed six months post transplant. The highest correlations with the six month gait speeds were the same gait speeds pretransplant. Regression analysis showed, however, that pretransplant normalized knee extension strength added significantly to the explanation of both comfortable and maximum gait speed six months post transplant. Diabetic status added significantly to the explanation of comfortable gait speed six months post transplant. The findings of this study support the predictive validity of preoperative knee extension strength measures in kidney transplant patients.

Discriminant Construct Validity of Hand-Held Dynamometry and Manual Muscle Testing in a Home Care Setting.

This study was conducted to investigate the discriminant construct validity of two measures of knee extension strength: hand-held dynamometry and manual muscle testing. The study employed a retrospective analysis of medical records and comparison of patient data with published reference values. The knee extension strength of 38 consecutive patients with a variety of problems requiring home based rehabilitation were measured bilaterally by hand-held dynamometry and manual muscle testing. Data were examined using analysis of variance, a Wilcoxon test, and contingency table analyses. Hand-held dynamometry was able to distinguish between the knee extension strength of patients and healthy subjects and between the stronger and weaker sides of both groups. Manual muscle testing was also able to differentiate between the strength of the stronger and weaker sides of patients. The sensitivity of manual muscle testing to differences between sides, however, was poor. The agreement between hand-held dynamometry and manual muscle testing as to the presence of a difference between sides was only fair (k=.240). If the identification of knee extension weakness relative to an external standard or a stronger side is important, hand-held dynamometry may be a better measurement procedure than manual muscle testing.

Muscle strength impairments and gait performance deficits in kidney transplantation candidates.

The purposes of this study of patients referred for renal transplant were to describe muscle strength impairments and deficits in gait performance and to establish the relationship between them. Twenty-six patients were tested. Muscle strength measurements included grip, elbow flexion, and shoulder abduction in the upper extremities, and ankle dorsiflexion, knee extension, hip abduction, and timed sit-to-stands in the lower extremities. Gait performance (level ground and stair) was quantified using ordinal scales and speed. Compared with healthy control subjects, patients demonstrated impairments in muscle strength and deficits in gait performance. Patients with diabetes demonstrated greater impairments and deficits than patients without diabetes. Patients with an active fistula demonstrated better grip strength in their upper extremity without the fistula. Gait performance was correlated significantly with lower extremity strength, with knee extension strength and weight providing the best prediction of gait speed (R2 = 0.478 to 0.617). The results of this study suggest that patients referred for renal transplantation possess both strength impairments and deficits in gait performance, the latter being related to the former. The clinician wishing to efficiently monitor strength impairments among patients referred for transplantation can obtain a reasonable indication of them from dynamometric grip and knee extension strength measurements.

The Effect of a High Resistance Exercise Program in Slowly Progressive Neuromuscular Disease

A 12-week high resistance home exercise program was completed by 10 subjects with slowly progressive neuromuscular diseases (NMD) and 6 normal control subjects (CTL). After evaluating baseline maximal isometric and isokinetic strength of the elbow flexors and knee extensors, subjects completed the home program using adjustable ankle and wrist cuff weights. One side of the body was randomly chosen for exercise. Subjects initially performed 1 set of 10 repetitions on 3 days a week and gradually increased to 5 sets of 10 repetitions on 4 days a week. The NMD group demonstrated significant (p < 0.05) gains in several knee extension isokinetic strength measures but loss of elbow flexion eccentric peak torque and work per degree. The CTL group demonstrated significant gains in all measures of knee extension strength, with improvement of elbow isokinetic eccentric work per degree as well. There was evidence of cross training to the nonexercised limbs for both groups. A high resistance training program, although well tolerated in NMD subjects with mild to moderate weakness, may cause some deleterious effects to diseased skeletal muscle. A high resistance training program appears to offer no advantage over a moderate resistance training program in this population.