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Introduction: Heavy-load strength training (HLT) is generally considered the Gold Standard exercise modality for inducing gains in skeletal muscle strength. However, use of heavy external exercise loads may be contraindicative in frail individuals. Low-load resistance exercise combined with partial blood-flow restriction (LL-BFR exercise) may offer an effective alternative for increasing mechanical muscle strength and size. The aim of this study was to compare the effect of LL-BFR training to HLT on maximal muscle strength gains. Prospero registration-id (CRD42014013382)., Materials and Methods: A systematic search in six healthcare science databases and reference lists was conducted. Data selected for primary analysis consisted of post-intervention changes in maximal muscle strength. A random-effects meta-analysis with standardized mean differences (SMD) was used., Results: Of 1413 papers identified through systematic search routines, sixteen papers fulfilled the inclusion criteria, totalling 153 participants completing HLT and 157 completing LL-BFR training. The magnitude of training-induced gains in maximal muscle strength did not differ between LL-BFR training and HLT (SMD of -0.17 (95% CI: -0.40; 0.05)). Low between-study heterogeneity was noted (I 2  = 0.0%, Chi 2 P = 9.65)., Conclusion: Low-load blood-flow-restricted training appears equally effective of producing gains in maximal voluntary muscle strength compared to HLT in 20- to 80-year-old healthy and habitually active adults., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To analyze if exercise interventions for patients with knee osteoarthritis (OA) following the American College of Sports Medicine (ACSM) definition of muscle strength training differs from other types of exercise, and to analyze associations between changes in muscle strength, pain, and disability., Methods: A systematic search in 5 electronic databases was performed to identify randomized controlled trials comparing exercise interventions with no intervention in knee OA, and reporting changes in muscle strength and in pain or disability assessed as standardized mean differences (SMD) with 95% confidence intervals (95% CI). Interventions were categorized as ACSM interventions or not-ACSM interventions and compared using stratified random effects meta-analysis models. Associations between knee extensor strength gain and changes in pain/disability were assessed using meta-regression analyses., Results: The 45 eligible trials with 4699 participants and 56 comparisons (22 ACSM interventions) were included in this analysis. A statistically significant difference favoring the ACSM interventions with respect to knee extensor strength was found [SMD difference: 0.448 (95% CI: 0.091-0.805)]. No differences were observed regarding effects on pain and disability. The meta-regressions indicated that increases in knee extensor strength of 30-40% would be necessary for a likely concomitant beneficial effect on pain and disability, respectively., Conclusion: Exercise interventions following the ACSM criteria for strength training provide superior outcomes in knee extensor strength but not in pain or disability. An increase of less than 30% in knee extensor strength is not likely to be clinically beneficial in terms of changes in pain and disability (PROSPERO: CRD42014015344)., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: People with meniscal tears are at high risk to develop or progress to knee osteoarthritis. Knee extensor weakness is considered a risk factor for osteoarthritis and is often reported in these individuals. The purpose of this systematic review and meta-analysis was to investigate knee extensor strength in people undergoing an arthroscopic partial meniscectomy (APM)., Methods: Six databases (Medline, CINAHL, SPORTDiscus, Embase, PEDro, and AMED) were searched up to June 22, 2014. Studies that measured knee extensor muscle strength in people age ≥30 years undergoing APM for a meniscal tear and used either a healthy control group or the contralateral leg to compare knee extensor muscle strength were included. Methodological quality was assessed using guidelines from the Centre for Reviews and Dissemination., Results: Eleven studies, in which participants were predominantly male, were included (n = 596). A moderate reduction in muscle strength was observed prior to APM compared to controls (standardized mean difference [SMD] 0.58, 95% confidence interval [95% CI] 0.04, 1.13) and continued up to 6 months postsurgery (SMD range -2.42 to -0.47). There was no difference in muscle strength at 2 years post-APM (SMD -0.01 [95% CI -0.36, 0.35]), while a moderate reduction was again apparent at 4 years post-APM (SMD -0.56, [95% CI -1.20, 0.08]) compared to controls., Conclusion: Our findings suggest that middle-aged and older individuals undergoing APM have reduced knee extensor muscle strength in the operated leg compared to control data. As meniscus pathology and knee extensor muscle weakness are risk factors for osteoarthritis, these results highlight the clinical importance of addressing muscle weakness in these individuals., (© 2015, American College of Rheumatology.)

Aim: Muscle strength is an excellent indicator of general health when based on reliable measurements. Muscle strength data for a healthy population are rare or non-existent. The aim of the present study was to measure a set of normal values for isometric and isokinetic muscle strength for all the major joint movements of the body and, from these data, to create a basis for comparison of the muscle strength of an individual with the expected value in a normal population., Methods: A randomly selected group, aged 20-80 years, from the Copenhagen City Heart Study were studied. The group was subgrouped according to age and gender. Isometric and isokinetic muscle strength was measured in each subject across the main joints in the body. A statistical model was developed that encompassed the three main muscle groups: upper limbs, trunk and lower limbs., Results: Muscle strength in healthy men decreases in a linear fashion from the age of 25 years down to between 54% and 89% at the age of 75 years, and seems not highly dependent on any other parameter than age. For women, the muscle strength is dependent on weight and is only related to age from around 40 years of age. The decrease in muscle strength from the age around 40 to 75 years is 48-92%. For most muscle groups, men are 1.5-2 times stronger than women, with the oldest men having strength similar to that observed among the youngest women., Conclusion: We developed a model to compare the isometric and isokinetic muscle strength of all the major joint movements of an individual with values for a healthy man or woman at any age in the range of 20-80 years. In all age groups, women have lower muscle strength than men. Men's muscle strength declines with age, while women's muscle strength declines from the age of 41 years.

The purpose of this study was to assess the effect of whole body vibration (WBV) exercise on muscle strength and proprioception in female patients with osteoarthritis in the knee (knee-OA). A single blinded, randomised, controlled trial was performed in an outpatient clinic on 52 female patients diagnosed with knee-OA (mean age 60.4 years+/-9.6). They were randomly assigned to one of 3 groups: 1. WBV-exercise on a stable platform (VibM; n=17 (mean age, 61.5+/-9.2)), WBV-exercise on a balance board (VibF; n=18 (mean age, 58.7+/-11.0)), or control group (Con; n=18 (mean age, 61.1+/-8.5)). The WBV groups trained twice a week for 8 weeks, with a progressively increasing intensity. The WBV groups performed unloaded static WBV exercise. The following were measured: knee muscle strength (extension/flexion) and proprioception (threshold for detection of passive movement (TDPM)). Self-reported disease status was measured using WOMAC. It was found that muscle strength increased significantly (p<0.001) in VibM compared to Con. Isometric knee-extension significantly increased (p=0.021) in VibM compared to Con. TDPM was significantly improved (p=0.033) in VibF compared to Con, while there was a tendency (p=0.051) for VibM to perform better compared to Con. There were no effects in the self-reported disease status measures. This study showed that the WBV-exercise regime on a stable platform (VibM) yielded increased muscle strength, while the WBV-exercise on a balance board (VibF) showed improved TDPM. The WBV-exercise is a time-saving and safe method for rehabilitation of women with knee-OA.

Objective: To test the hypothesis that fibromyalgia (FM) patients with reduced lower extremity strength are more symptomatic and tender than FM patients with normal muscle strength., Methods: A total of 840 FM patients and 122 healthy subjects were evaluated between 1998 and 2005. All of the patients completed version 1 of the Fibromyalgia Impact Questionnaire (FIQ) and were assessed for tender points and knee muscle strength. All subjects underwent bilateral isokinetic knee muscle strength testing in flexion and extension. Normative knee muscle strength values were calculated from the healthy subjects, and the FM cohort was divided in 2 groups: 1) patients with normal muscle strength and 2) patients with low muscle strength (2 SDs below normal). The clinical characteristics of these 2 groups were compared., Results: Significantly reduced knee muscle strength was found in 52% of the patients. There were no clinically significant differences between patients with low versus normal muscle strength. There were no clinically significant correlations between total FIQ score, tender point count, and muscle strength. Only 4.6% of the FIQ scores and 5.1% of the tender point counts were explained by muscle strength., Conclusion: Significantly reduced knee muscle strength was found in more than half of the patients. Patients with subnormal muscle strength were not more symptomatic or tender than patients with normal muscle strength. There were no clinically significant correlations between FIQ, tender point count, and muscle strength; therefore, reduced knee muscle strength appears to be a common objective abnormality in FM that is independent of measurements of disease activity. The implication of this finding in regard to the clinical assessment of FM needs further study.

Background: Today, breast reconstruction with autologous tissue is most commonly done either as a free muscle sparring TRAM flap or as a DIEP flap. Studies of donor site morbidity have shown an advantage in using the DIEP flap. However, this procedure might also be associated with an increased risk of flow related complications and it is also thought to be more demanding and time consuming. A few studies have evaluated the abdominal wall strength after dissection of a TRAM flap or a DIEP flap. However, these studies do not distinguish between the various types of free TRAM flaps and they also compare TRAM procedures preformed in an early period to DIEP procedures done in a later period., Methods: We used an isokinetic dynamometer to measure concentric, eccentric and isometric abdominal muscle strength in 32 patients who had had a unilateral breast reconstruction with a free MS-2 (15) or a DIEP (17) flap in the year 2003., Results: No significant reduction in muscle strength was observed for concentric or isometric muscle strength. However, significant lower eccentric muscle strength was found in the TRAM compared to the DIEP group (p=0.05). There was no significant difference in abdominal strength between the two flap groups at low to moderate work intensity (isometric/concentric). At the greatest work intensity (eccentric muscle strength) the patients reconstructed with a DIEP flap had a clinical small, but significant advantage over the patients reconstructed with a MS-2 TRAM flap.

The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee at 60° s−1. Thirteen (nine women, four men) healthy participants were measured five times using the Biodex and once using the Lido dynamometer. The intervals between the first four tests were 20 min, and 1 week between tests 4 and 5. Between Biodex and Lido measurements there was a 20 min time interval. When comparing the first five measurements (Biodex), no systematic effect over time and an excellent reliability were found with respect to elbow and knee flexion and extension. No difference in muscle strength (Nm) between the Biodex and Lido was observed for knee flexion (P = 0·59), knee extension (P = 0·18) and elbow extension (P = 0·63). However, elbow flexion showed a 14·8% (95% CI: 11·2–18·4%;P = 0·0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when comparing Biodex and Lido on elbow flexion, but the difference did not outrange the expected variation found with a typical isokinetic measurement, which is why both sets of equipment seem applicable in clinical practice. [ABSTRACT FROM AUTHOR]