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Results for “Muscle Strength”

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PubMed1994

Control of breathing and respiratory muscle strength in patients with multiple sclerosis.

In 11 patients with moderately severe multiple sclerosis, lasting 11.2 +/- 7.3 years, in stable condition, and in 10 age- and sex-matched control subjects, we investigated lung function, respiratory muscle strength, and ventilatory control system. Respiratory muscle strength was assessed by measuring maximal inspiratory and expiratory mouth pressures (Pimax and Pemax, respectively). Respiratory central drive was evaluated in terms of neuromuscular (P0.1) and ventilatory (Ve) output, breathing room air and during CO2 rebreathing. In the absence of any significant impairment of lung function, patients showed a reduction of Pimax and Pemax amounting to about 40 percent and 60 percent of the predicted value at functional residual capacity (FRC), respectively; a significant, inverse correlation was found between both Pimax and Pemax at FRC and the severity score of the disease. While at rest Ve was similar to that of control subjects, baseline P0.1 was significantly higher in patients (1.97 +/- 0.79 vs 0.97 +/- 0.20 cm H2O, p < 0.005). Compared with the control group, during CO2 rebreathing P0.1/PetCO2 slope, although less steep, was not dissimilar in patients (0.34 +/- 0.13 vs 0.46 +/- 0.19 cm H2O/mm Hg, NS); on the other hand, Ve/PetCO2 slope was much lower in the patient group (1.93 +/- 0.91 vs 3.27 +/- 1.11 L/min/mm Hg, p < 0.01) and was significantly related to the functional stage of disease and to Pimax and Pemax values at FRC. These results indicate that in patients with clinically stable, moderately severe multiple sclerosis, the respiratory muscle function is abnormal. Moreover, the inspiratory drive at rest is increased and the drive response to CO2 appears normal, while the ventilatory response to CO2 is significantly impaired. Respiratory muscle weakness (and/or lack of coordination) could explain, at least in part, the lower ventilatory response in these patients, whereas the mechanism of increased rate of the initial inspiratory force generation remains unclear.

Adult↗

PubMed1997

Postpolio muscular dysfunction: relationships between muscle energy metabolism, subjective symptoms, magnetic resonance imaging, electromyography, and muscle strength.

Eleven patients with previous polio were studied. The concentration of energy-related metabolites and energy charge was measured from the vastus lateralis muscle, as was isometric muscle strength of knee extension. Cross-sectional area of the quadriceps femoris muscle was calculated from magnetic resonance imaging. Reinnervation was studied using macroelectromyography. Muscle weakness, pain, and newly acquired muscle weakness in the legs was estimated by the patients. The findings in the legs in which the patients experienced new loss of muscle function were compared with the stable legs. There were no significant differences between these groups in any of the objectively measured variables. Only hip pain correlated with new loss of muscle function. Creatine phosphate was decreased in 5 patients. The symptoms and subjective muscle strength did not correlate with any of the objective measurements. There were no significant relationships between energy-related metabolites and postpolio symptoms.

Adult↗

PubMed2002

Birth weight, childhood size, and muscle strength in adult life: evidence from a birth cohort study.

Environmental influences during gestation may have long-term effects on adult muscle strength. It is not known how early in adult life such effects are manifest and whether they are modified by childhood body size. The authors examined the relation between birth weight and hand grip strength in a prospective national birth cohort of 1,371 men and 1,404 women from the Medical Research Council National Survey of Health and Development who were aged 53 years in 1999. A positive relation between birth weight and adult grip strength remained after adjustment first for adult height and weight and then additionally for childhood height and weight (p = 0.006 for men and p = 0.01 for women). The effects of birth weight on grip strength did not vary by childhood or current body size and were not confounded by social class. To the authors' knowledge, this is the first study to show that birth weight has an important influence on muscle strength in midlife independent of later body size and social class. It suggests that birth weight is related to the number of muscle fibers established by birth and that even in middle age compensating hypertrophy may be inadequate. As the inevitable loss of muscle fibers proceeds in old age, a deficit in the number of fibers could threaten quality of life and independence.

Birth Weight↗

PubMed2004

Contribution of muscle strength and integration of afferent input to postural instability in persons with stroke.

OBJECTIVE: To determine the relationship of muscle strength to postural sway in persons with stroke under standing conditions in which vision and ankle proprioception were manipulated. METHODS: Forty persons with stroke and 40 healthy older adult controls were recruited from the community and underwent balance testing consisting of 6 conditions that manipulate vision and somatosensory information while standing. Postural sway was measured during each condition. In addition, lower extremity joint torques and cutaneous sensation from the plantar surface of the foot were assessed. RESULTS: Postural sway was increased with more challenging standing conditions (i.e., when multiple sensory systems were manipulated) to a greater extent with the group with stroke compared to controls. Muscle strength was only correlated to sway during the most challenging conditions. Furthermore, a greater number of persons with stroke fell during the balance testing compared to controls. CONCLUSIONS: Impairments in re-weighting/integrating afferent information, in addition to muscle weakness, appear to contribute to postural instability and falls in persons with stroke. These findings can be used by clinicians to design effective interventions for improving postural control following stroke.

Aged↗

PubMed1993

A biomechanical analysis of muscle strength as a limiting factor in standing posture.

We developed a method for studying muscular coordination and strength in multijoint movements and have applied it to standing posture. The method is based on a musculoskeletal model of the human lower extremity in the sagittal plane and a technique to visualize, geometrically, how constraints internal and external to the body affect movement. We developed an algorithm to calculate the set of all feasible accelerations (i.e., the 'feasible acceleration set', or FAS) that muscles can induce. For the ankle, knee, and hip joints in the sagittal plane, this set is a polyhedron in three dimensions. Using the volume of the FAS as an indicator of overall mobility, we found that strengthening muscles on the posterior side (as opposed to the anterior) of the body would cause greater increases in mobility. Employing the experimental observations of others, we also found that acceleration constraints greatly reduce the range of feasible accelerations. We then defined a set of four basic acceleration vectors which, when used in various combinations, can produce the repertoire of postural movements. We used linear programming to find the maximum magnitudes of these vectors, and the sensitivity of these magnitudes to muscle strength, thereby delineating those muscles which, if strengthened, would cause the greatest increase in the body's ability to generate the basic acceleration vectors. For our particular model, those muscle groups were found to be hamstrings, tibialis anterior, rectus femoris, and gastrocnemius. These muscle groups would be of great importance in cases involving severely reduced muscle strength. This methodology may therefore be useful for purposes such as design of functional electrical stimulation controllers or exercises for persons at risk for falling.

Acceleration↗

PubMed1996

Effects of concentric and eccentric training on muscle strength, cross-sectional area, and neural activation.

We compared the effects of concentric (Con) and eccentric (Ecc) isokinetic training on quadriceps muscle strength, cross-sectional area, and neural activation. Women (age 20.0 +/- 0.5 yr) randomly assigned to Con training (CTG; n = 16), Ecc training (ETG; n = 19), and control (CG; n = 19) groups were tested before and after 10 wk of unilateral Con or Ecc knee-extension training. Average torque measured during Con and Ecc maximal voluntary knee extensions increased 18.4 and 12.8% for CTG, 6.8 and 36.2% for ETG, and 4.7 and -1.7% for CG, respectively. Increases by CTG and ETG were greater than for CG (P < 0.05). For CTG, the increase was greater when measured with Con than with Ecc testing. For ETG, the increase was greater when measured with Ecc than with Con testing. The increase by ETG with Ecc testing was greater than the increase by CTG with Con testing. Corresponding changes in the integrated voltage from an electromyogram measured during strength testing were 21.7 and 20.0% for CTG, 7.1 and 16.7% for ETG, and -8.0 and -9.1% for CG. Quadriceps cross-sectional area measured by magnetic resonance imaging (sum of 7 slices) increased more in ETG (6.6%) than in CTG (5.0%) (P < 0.05). We conclude that Ecc is more effective than Con isokinetic training for developing strength in Ecc isokinetic muscle actions and that Con is more effective than Ecc isokinetic training for developing strength in Con isokinetic muscle actions. Gains in strength consequent to Con and Ecc training are highly dependent on the muscle action used for training and testing. Muscle hypertrophy and neural adaptations contribute to strength increases consequent to both Con and Ecc training.

Adolescent↗

PubMed1995

Effects of interpleural bupivacaine on respiratory muscle strength and pulmonary function.

BACKGROUND: Several reports suggest that interpleural local anesthetics may have deleterious effects on respiratory function. The current study investigated the effects of interpleural bupivacaine on human respiratory muscles and lung function. METHODS: Thirteen patients (55 +/- 4 yr old) with normal respiratory function and scheduled for cholecystectomy entered the study before surgery. Respiratory parameters were compared before and after the interpleural administration of 20 ml 0.5% bupivacaine plus 1:200,000 epinephrine while patients were supine; we evaluated breathing pattern, dynamic and static lung volumes, airway conductance, maximal inspiratory pressures (at the mouth; at the esophagus [Pessniff]; at the abdomen [Pgasniff]; and transdiaphragmatic [Pdisniff]), functional reserve (tension-time index) of the diaphragm, and maximal expiratory pressures (at the mouth; at the esophagus [Pescough]; and at the abdomen [Pgacough]). Hemoglobin oxygen saturation by pulse oximetry, heart rate, and mean arterial pressure were continuously monitored. RESULTS: Respiratory rate (15 +/- 1 to 19 +/- 1 breaths/min; P < 0.01) and heart rate (78 +/- 3 to 83 +/- 3 beats/min; P < 0.01) were slightly increased. Dynamic and static lung volumes, airway conductance, hemoglobin saturation, and the remaining breathing pattern parameters were unchanged. Regarding respiratory muscles, maximal inspiratory pressure at the mouth, Pessniff, and tension-time index of the diaphragm did not change. Pdisniff decreased slightly (102 +/- 10 to 92 +/- 10 cmH2O; P < 0.05) because of a change in Pgasniff (24.2 +/- 7.4 to 18.4 +/- 6.8 cmH2O; P < 0.05). Maximal expiratory pressure at the mouth remained unaltered, but Pgacough decreased (108 +/- 10 to 92 +/- 8 cmH2O; P < 0.01), and Pescough showed a trend to decrease (92 +/- 13 to 78 +/- 10 cmH2O; P = 0.074). CONCLUSIONS: In our experimental conditions, interpleural bupivacaine did not significantly change lung function or inspiratory muscle strength but induced a slight decrease in abdominal muscle strength. Although this effect was minimal, its clinical relevance needs to be evaluated further in patients with impaired respiratory function.

Adult↗

PubMed2001

Muscle strength and function before and after anterior cruciate ligament reconstruction using semitendonosus and gracilis.

This study assessed the quadriceps and hamstring strength before and 6 months after anterior cruciate ligament (ACL) reconstructive surgery using the hamstrings and related the findings to functional performance. Six months after surgery is a critical time for assessment as this is when players are returning to sport. Maximum isokinetic strength of 31 patients with complete unilateral ACL ruptures was measured at speeds of 60 degrees and 120 degrees per second. Functional assessment included the single hop, the triple hop, the shuttle run, side-step and carioca tests. All patients underwent a controlled quadriceps emphasized home-based physiotherapy program both before and after surgery. Results show that before surgery there was a 7.3% quadriceps strength deficit at 60 degrees per second compared to the uninjured leg but no hamstring strength deficit. After surgery there was a statistically significant but relatively small loss of muscle strength. The quadriceps strength deficit had increased to 12% and there was a 10% hamstring deficit. Post-operatively there was an 11% and 6.3% improvement in the hop tests, a 9% (P < 0.01) improvement in the shuttle run, a 15% (P < 0.001) improvement in the side step and a 24% (P < 0.001) improvement in the carioca tests (P < 0.001) despite the loss of muscle strength.

Adult↗

PubMed2005

Comparison of multifidus muscle atrophy and trunk extension muscle strength: percutaneous versus open pedicle screw fixation.

STUDY DESIGN: This study was conducted by retrospective case selection and prospective observation of longitudinal changes of the multifidus muscle cross-sectional area and of trunk extension muscle strength in percutaneous and open pedicle screw fixations. OBJECTIVES: To compare postoperative multifidus muscle atrophy and trunk muscle performance of percutaneous pedicle screw fixation against those of open pedicle screw fixation. SUMMARY OF BACKGROUND DATA: Recent attempts to combine percutaneous pedicle screw fixation with minimally invasive fusion techniques are based on an anecdotal presupposition that percutaneous pedicle screw fixation is superior to its open counterpart. However, the benefits of percutaneous pedicle screw fixation are currently poorly defined. METHODS: Nineteen enrolled patients were divided as follows: 11 in the open pedicle screw fixation group (OPF group) and eight in the percutaneous pedicle screw fixation group (PPF group). The preoperative and postoperative cross-sectional area and T2-weighted signal intensity of multifidus muscle were measured by MRI, and trunk extension muscle strength was measured. In addition, various clinical variables were compared between two groups. RESULTS: There was significant decrease in the cross-sectional area of multifidus muscle in the OPF group. In contrast, the results in the PPF group showed no statistical difference between preoperative results and that of the follow-up MRI. Although percutaneous pedicle screw fixation had positive effects on postoperative trunk muscle performance, clinical outcomes were not significantly different in areas of pain score, JOA score, and patient's opinion regarding the outcome of the surgery. However, percutaneous pedicle screw fixation caused less blood loss, and the proportion of patients who did not need postoperative oral analgesics was greater in the PPF group. CONCLUSIONS: Percutaneous pedicle screw fixation caused less paraspinal muscle damage than open pediclescrew fixation and had positive effects on postoperative trunk muscle performance.

Aged↗

PubMed1995

The effect of lumbar belts on isolated lumbar muscle. Strength and dynamic capacity.

STUDY DESIGN: This study analyzed the effect of lumbar support belts on functional performance. OBJECTIVE: To compare lumbar muscle strength and lifting capacity with and without a lumbar belt. SUMMARY OF BACKGROUND DATA: Industrialized settings have begun to encourage the use of lumbar support belts for their employees. It is believed that the belts may decrease the risk of injury and enhance the functional performance of the individual. METHODS: Twenty-two subjects (average age, 27.5 years) were tested on four separate days to evaluate the effect of a commercially available belt on isolated lumbar isometric strength and functional dynamic lifting capacity. All subjects had no history of low back problems. The order of testing with and without a belt was randomized for both conditions. On the first 2 days, subjects performed a seven-angle isometric lumbar extension strength test, 1 day with and 1 day without a lumbar belt. On the following 2 days, subjects were tested to evaluate functional capacity with and without a lumbar belt. The functional capacity evaluation was performed by progressively lifting weighted canisters from various levels. Heart rates were monitored to ensure that a maximum effort was achieved over the different days. RESULTS: T tests revealed that isometric lumbar strength and functional lifting capacity was not significantly affected by the belt. CONCLUSION: The use of a lumbar belt does not enhance isometric lumbar muscle strength or dynamic lifting capacity.

Adult↗

PubMed2002

Oral amino-acid provision does not affect muscle strength or size gains in older men.

PURPOSE: The intent of this investigation was to examine the effects of a daily oral provision consisting of amino acids (L-lysine, L-leucine, L-valine, L-phenylalanine, L-threonine, L-histidine, L-isoleucine, and L-methionine) in combination with carbohydrates (dextrose, sucrose, and fructose) on whole muscle strength and size characteristics during a 12-wk progressive knee extensor resistance training (PRT) program in older men (>65 yr). METHODS: Seventeen older men were randomly assigned to either the experimental (EX) or control (CN) groups. The EX (N = 8) and CN (N = 9) groups had the following characteristics-EX: 70.8 +/- 1.5 yr, 91.0 +/- 4.9 kg, and 177.0 +/- 3.9 cm; CN: 72.1 +/- 1.9 yr, 75.4 +/- 4.7 kg, and 176.1 +/- 3.0. Pre and post PRT maximal unilateral isometric torque (N.m), isokinetic torque (1.05, 1.57, 2.09, 3.14, 4.19, and 5.24 rad.s-1), work capacity (30 consecutive reps at 3.14 rad.s-1) torque, one repetition maximum (1RM) bilateral isotonic strength, and whole muscle cross-sectional area (CSA) of the mid-thigh were performed by computed tomography on each subject. RESULTS: All variables showed an improvement with training (P < 0.05); however, there were no differences between the groups. Both groups increased in isometric strength by 21%, and isokinetic torque by 24% to 11% with the varying velocities (1.05-5.24 rad.s-1). Whole muscle 1RM strength and thigh CSA increased 50% and 6.5%, respectively. Additionally, voluntary torque/CSA increased 12% in both the EX and CN groups (P < 0.05). CONCLUSIONS: In conclusion, these data suggest that whole muscle strength and size are not enhanced with a postexercise daily provision of an oral amino-acid complex during 12 wk of PRT in older men.

Administration, Oral↗

PubMed2004

Effect of neuromuscular training on proprioception, balance, muscle strength, and lower limb function in female team handball players.

OBJECTIVE: Introduction of a neuromuscular training program will increase muscle strength, balance, and proprioception in elite female handball players. DESIGN: Prospective intervention study. PARTICIPANTS: Thirty-five female team handball players from 2 teams in the elite division participated. Their mean age was 23 (+/-2.5) years, and their mean weight was 69.2 (+/-7.3) kg. They had played handball for 14.9 (+/-3.2) years, 4.7 (+/-2.8) years at the top level. The total number of training hours per week was 10 to 11. INTERVENTION: Based on earlier studies and knowledge about common risk situations in team handball, an anterior cruciate ligament (ACL) injury prevention program with 3 different sets of exercises was developed, each set with a 5-step progression from simple to more challenging exercises. The teams were instructed to use the program a minimum of 3 times a week during a training period of 5 to 7 weeks, and then once a week during the season. The duration of each training session was approximately 15 minutes. MAIN OUTCOME MEASURES: Balance (KAT 2000), proprioception (threshold to detection of passive motion), muscle strength (Cybex 6000), and 3 functional knee tests. The players were tested pretraining (test 1) and 8 weeks (test 2) and 12 months (test 3) after the training started. RESULTS: There was a significant improvement in dynamic balance between test 1 and test 2, with a balance index (BI) of 924 (+/-225) and 778 (+/-174), respectively (P = 0.01). The effect on dynamic balance was maintained 1 year after training (BI, 730 +/- 156). For static balance, no statistically significant changes were found. For the other variables measured, there were no statistical differences during the study period. CONCLUSION: The ACL injury prevention training program improved dynamic balance in an elite team handball players.

Adult↗

PubMed1995

Standing balance, lower extremity muscle strength, and walking performance of patients referred for physical therapy.

The purposes of this study of 30 patients referred to physical therapy were to describe the reliability of two measures of impairment and a measure of gait performance and to examine the relationships between the impairment and gait measures. The impairments measured were standing balance and muscle strength of the lower extremities, the former with a seven-level ordinal scale and the latter with a hand-held dynamometer. Gait performance was measured using the seven-category scale of the Functional Independence Measure. Interday reliability was acceptable for all three measures, standing balance (weighted Kappa = .95), muscle strength (intraclass correlation coefficients = .871 to .951), and gait (weighted Kappa = .915). A Spearman correlation of .860 was found between balance and gait measures. The correlations between the strengths of various muscle groups and gait were lower (.138 to .581). Multiple regression identified none of the strength scores as offering additional independent explanation of gait performance. Balance, as scored, appears to be a reliable and valid measure worth broader application among hospitalized patients.

Adult↗

PubMed1996

CPAP improves inspiratory muscle strength in patients with heart failure and central sleep apnea.

Patients with congestive heart failure (CHF) suffer from respiratory muscle weakness which may contribute to dyspnea. Nasal continuous positive airway pressure (NCPAP) can improve left ventricular ejection fraction (LVEF) and reduce dyspnea in patients with CHF and Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) but its effects on respiratory muscle strength are not known. We therefore studied the effects of NCPAP on maximal inspiratory and expiratory pressures (MIP and MEP, respectively), LVEF, dyspnea, and fatigue in patients with chronic CHF and CSR-CSA over 3 mo. Eight patients were randomized to control and nine to nightly NCPAP. There were no significant changes in any of these factors in the control group during the study. In contrast, among the NCPAP group, MIP increased from 79.3 +/- 8.1 to 90.7 +/- 10.4 cm H2O (mean +/- SEM; p < 0.02), LVEF increased from 24.0 +/- 4.0 to 32.6 +/- 6.6% (p < 0.02) and symptoms of dyspnea and fatigue were alleviated. However, MEP did not change. In addition, the number of apneas and hypopneas decreased from 49 +/- 11 to 17 +/- 7 per hour of sleep (p < 0.001) and mean low Sao2 during sleep increased from 87.9 +/- 1.0 to 93.0 +/- 1.0% (p < 0.01). Our data indicate that nightly application of NCPAP in patients with CHF and CSR-CSA improves inspiratory muscle strength and LVEF, and relieves dyspnea and fatigue.

Aged↗

PubMed1995

[Effects of weight training on muscle strength and exercise capacity in patients after myocardial infarction].

The effect of combined aerobic and weight training on indexes of muscle strength and exercise capacity was investigated in 59 patients after myocardial infarction. Subjects were randomly assigned into three groups: group I performing combined aerobic and weight training (n = 22), group II performing ordinary aerobic training alone (n = 19) and group III not performing physical training (n = 18). Before and after the training, isokinetic knee extension strength was measured and cardiopulmonary exercise testing was performed. Physical training was prescribed for 8 weeks. Weight training of knee extensors was performed at 60% of 1 repetition maximum and aerobic training was prescribed at the heart rate of anaerobic threshold (AT) level. After 8 weeks, the increase of isokinetic knee extension strength was significantly greater in group I (26 +/- 14%) than group II (6 +/- 8%) and III (4 +/- 8%). Increases in peak VO2, exercise time, AT and peak O2 pulse were greater in groups I and II than group III. Furthermore, increase of exercise time was greater in group I (25 +/- 14%) than group II (16 +/- 9%). The rating of perceived exertion in submaximal exercise decreased significantly only for group I. In patients with myocardial infarction, combined aerobic and weight training is a more effective method for increasing muscle strength and exercise capacity than only ordinary aerobic training.

Aged↗

PubMed2004

Association of neck pain, disability and neck pain during maximal effort with neck muscle strength and range of movement in women with chronic non-specific neck pain.

Several studies have reported lower neck muscle strength in patients with chronic neck pain compared to healthy controls. The aim of the present study was to evaluate the association between the severity of neck pain and disability with neck strength and range of movement in women suffering from chronic neck pain. One hundred and seventy-nine female office workers with chronic neck pain were selected to the study. The outcome was assessed by the self-rating questionnaires on neck pain (visual analogue scale, Vernon's disability index, Neck pain and disability index) and by measures of the passive range of movement (ROM) and maximal isometric neck muscle strength. No statistically significant correlation was found between perceived neck pain and the disability indices and the maximal isometric neck strength and ROM measures. However, the pain values reported during the strength tests were inversely correlated with the results of strength tests (r=-0.24 to -0.46), showing that pain was associated with decreased force production. About two-thirds of the patients felt pain during test efforts. Pain may prevent full effort during strength tests and hence the production of maximal force. Thus in patients with chronic neck pain the results do not always describe true maximal strength, but rather the patients' ability to bear strain, which may be considerably influenced by their painful condition. The results of the present study suggest that rehabilitation in cases of chronic neck pain should aim at raising tolerance to mechanical strain.

Adult↗

PubMed1992

Spinal mobility and trunk muscle strength in 15-year-old schoolchildren with and without low-back pain.

From a population of 1,503 schoolchildren, 38 15-year-old children suffering from low-back pain and 38 asymptomatic controls were selected for testing of spinal mobility and trunk muscle strength. The asymptomatic controls were matched by age, sex, and school class. In the group with recurrent or continual low-back pain (17 boys and 21 girls), the boys were over 4 cm taller than those in the control group. In both sexes sagittal mobility was decreased in lumbar extension and straight leg raising, and increased in lumbar flexion. Endurance strength in the abdominal and back muscles was decreased compared to the control pupils, who reported no back pain at all in the questionnaire collected 1 year before the testing procedure. The pupils reporting sciatica (n = 7) at some time, in addition to recurrent low-back pain, had decreased lumbar flexion and side bending compared to those with recurrent low-back pain (n = 31) without sciatica. The results of the study indicated that in this growing-age population there was a subgroup with recurrent low-back pain having a different spinal mobility pattern as well as decreased trunk muscle strength.

Adolescent↗

PubMed2002

Skeletal muscle strength as a predictor of all-cause mortality in healthy men.

Low muscle strength is associated with mortality, presumably as a result of low muscle mass (sarcopenia) and physical inactivity. Grip strength was longitudinally collected in 1071 men over a 25-year period. Muscle mass was estimated by using 24-hour creatinine excretion and physical activity values, obtained by questionnaire. Survival analysis examined the impact of grip strength and rate of change in strength on all-cause mortality over 40 years. Lower and declining strength are associated with increased mortality, independent of physical activity and muscle mass. In men <60 years, rate of loss of strength was more important than the actual levels. In men >/=60 years, strength was more protective than the rate of loss, which persisted when muscle mass was considered. Strength and rate of change in strength contribute to the impact of sarcopenia on mortality. Although muscle mass and physical activity are important, they do not completely account for the impact of strength and changes in strength.

Adult↗