Development of bilateral muscular strength through ipsilateral exercise.
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OBJECTIVE: To test the effect of two exercise regimes on health-related quality of life (HRQoL) and ambulatory capacity. DESIGN: Randomized controlled trial. SUBJECTS: Seventy-seven community-dwelling physically frail people over 75 years of age (mean = 81, SD = 4.5). INTERVENTIONS: Home training (HT, N= 38) comprised twice daily functional balance and strength exercises and three group meetings. Combined training (CT, N= 39) included group training twice weekly and the same home exercises. Interventions lasted 12 weeks. Physiotherapists ran both programmes. Home exercises were recorded daily. MAIN MEASURES: HRQoL was assessed by SF-36, and ambulatory capacity by walking speed and frequency and duration of outdoor walks. RESULTS: Following intervention, CT improved the SF-36 mental health index significantly more than HT (p = 0.01). The SF-36 physical health index (p = 0.002) and walking speed (p = 0.02) demonstrated improvements, but no group differences. Six months after cessation of intervention there was still overall improvements on the mental health index (p = 0.032), borderline overall improvements on the physical health index (p = 0.057), higher weekly number of outdoor walks for the CT group than for the HT group (p = 0.027) and an improved habitual walking speed in the CT group only (p = 0.022). CONCLUSIONS: HT improved HRQoL and walking speed, but additional group training gave larger benefits on mental health. Group training away from home may be beneficial for mental health and ambulatory capacity.
BACKGROUND AND AIMS: Exercise in older people may reduce falls and improve functional abilities. Less is known about the optimal amount of training. The aim of this study was to determine the effectiveness of home training, and whether group training in addition to home training enhances the effect. METHODS: This randomized trial included 77 persons aged 75 years and older (mean 81, SD 4.5), living at home. Home training (HT) comprised twice-daily functional balance and strength exercises and 3 group meetings. Combined training (CT) included group training twice weekly and the same home exercises. The trial lasted 12 weeks. Physical therapists ran both programs. Exercises and falls were recorded daily. We assessed function at baseline, 3 and 9 months, and falls at one year. RESULTS: Mean participation for group meetings was 2.5 out of 3 (HT group) and, for group training sessions, 21 out of 24 (CT group). The mean numbers of daily home sessions were 1.29 and 1.35 in the HT and CT groups. Overall improvement, but no group differences, were found at 3 months for walking speed, Figure of Eight, Timed Up & Go, Maximum Step Length, Timed Pick-up and Sit-to-stand (p<0.02). Posturography (p=0.85) and isometric quadriceps strength (p=0.26) showed no improvement. Function at 9 months was equivalent to baseline level. There were no group differences in fall rate (p=0.78) or time to first fall (p=0.84). CONCLUSIONS: Daily home training supervised by physical therapists improved functional abilities. Supplementary individualized group training gave no additional effect. The effect on function was not present 6 months after the end of the intervention.
Physiotherapists typically use a variety of modes to treat their clients, including manual therapy. The literature cautions against the use of manual therapy in individuals with osteoporosis, (Musculoskeletal Manipulation: Evaluation of the Scientific Evidence, Charles C Thomas Publisher, Springfield, IL; Common Vertebral Joint Problems, 2nd Edition, Churchill Livingstone, New York; Maitland's Vertebral Manipulation, 6th Edition, Butterworth-Heinemann, Boston; Br. J. Sports Med. 37 (2003) 195-196) yet clinical experience (Br. J. Sports Med. 37 (2003) 195-196) and published cases (J. Manip. Physiol. Ther. 15(7) (1992) 450-454) suggest that these techniques are still being used by at least some clinicians. The purpose of this study was to measure the most common treatment modes used by a random sample of physiotherapists practicing in the province of British Columbia (BC) in the treatment of individuals with osteoporosis. To assess whether physiotherapists in BC have concerns about the use of manual therapy in individuals with osteoporosis, particularly whether physiotherapists have concerns about fracture as a complication of treatment. This cross-sectional study of 171 physiotherapists in BC used a questionnaire developed by the physiotherapist in the Osteoporosis Program at the BC Women's Health Centre (a part of the Children's & Women's Health Centre of BC). The response rate (67/171) was 39%. Ninety-seven per cent of respondents reported using strength exercises and postural reeducation, while 45% reported using manual therapy in this population. Ninety-one per cent of respondents reported having concerns about the use of manual therapy. Vertebral fracture and rib fracture were the most commonly reported concerns. These findings suggest that most physiotherapists practicing in BC, Canada use evidence-based methods (i.e. strength training) when treating individuals with osteoporosis, a large number use manual therapy, and most have concerns about its use. Physiotherapists are most concerned about fractures, in particular vertebral fracture, but injury to other musculoskeletal tissues is also of concern. Studies of safety and effectiveness of manual therapy in this population are needed to guide clinical practice.
Reflex mechanisms from contracting skeletal muscle have been shown to be important for cardiovascular, neuroendocrine, and extramuscular fuel-mobilization responses in exercise. Furthermore, because hypoxia results in exaggerated metabolic changes in contracting muscle, the present study evaluated whether enhancement of cardiovascular and neuroendocrine responses by hypoxia during exercise is influenced by neural feedback from contracting muscle. Seven healthy males cycled at 46% maximal O(2) uptake for 20 min both during normoxia and at 11.5% O(2), and both without and with epidural anesthesia (EA; 20 ml 0.25% bupivacain, resulting in cutaneous hypesthesia below T10-T12 and 25% reduction in maximal leg strength). Exercise to exhaustion was also performed at 7.8% O(2). The exercise-induced increases in heart rate; cardiac output; leg blood flow; plasma concentrations of growth hormone, adrenocorticotropin, cortisol, and catecholamines; renin activity; glucose production and disappearance; norepinephrine spillover [2, 190 +/- 341 ng/min (exercise at 11.5% O(2)) vs. 988 +/- 95 ng/min (exercise during normoxia)]; lactate release from and glucose uptake in the leg; and the decreases in plasma insulin and free fatty acids were exaggerated in hypoxia (P < 0.05). In muscle, concentrations of lactate, creatine, and inosine 5'-monophosphate were higher, and those of phosphocreatine were lower after exercise in hypoxia compared with normoxia. The exercise-induced increase in mean arterial blood pressure was not affected by hypoxia, but it was reduced by EA [108 +/- 4 mmHg (control) vs. 97 +/- 4 mmHg (EA); P < 0.05], and the reduction was more pronounced during severe hypoxia compared with normoxia. Apart from this, time to exhaustion at extreme hypoxia, circulatory responses, concentrations of neuroendocrine hormones, and extramuscular substrate mobilization were not diminished by EA. In conclusion, in essence the hypoxia-induced enhancement of systemic adaptation to exercise is not mediated by neural feedback from working muscle in humans.
OBJECTIVES: This randomized controlled trial studied the effects of a low- to moderate-intensity group exercise program on strength, endurance, mobility, and fall rates in fall-prone elderly men with chronic impairments. METHODS: Fifty-nine community-living men (mean age = 74 years) with specific fall risk factors (i.e., leg weakness, impaired gait or balance, previous falls) were randomly assigned to a control group (n = 28) or to a 12-week group exercise program (n = 31). Exercise sessions (90 minutes, three times per week) focused on increasing strength and endurance and improving mobility and balance. Outcome measures included isokinetic strength and endurance, five physical performance measures, and self-reported physical functioning, health perception, activity level, and falls. RESULTS: Exercisers showed significant improvement in measures of endurance and gait. Isokinetic endurance increased 21% for right knee flexion and 26% for extension. Exercisers had a 10% increase (p < .05) in distance walked in six minutes, and improved (p < .05) scores on an observational gait scale. Isokinetic strength improved only for right knee flexion. Exercise achieved no significant effect on hip or ankle strength, balance, self-reported physical functioning, or number of falls. Activity level increased within the exercise group. When fall rates were adjusted for activity level, the exercisers had a lower 3-month fall rate than controls (6 falls/1000 hours of activity vs 16.2 falls/1000 hours, p < .05). DISCUSSION: These findings suggest that exercise can improve endurance, strength, gait, and function in chronically impaired, fall-prone elderly persons. In addition, increased physical activity was associated with reduced fall rates when adjusted for level of activity.
AIM: We assessed the long-term benefits of inspiratory muscle training (IMT) on inspiratory muscle strength, exercise capacity, the perception of dyspnea, quality of life, primary care use, and hospitalizations in patients with significant COPD. PATIENTS: Forty-two consecutive COPD patients with FEV(1) < 50% of predicted were randomized into a group that received IMT for 1 year, and a control group that received training with a very low load. RESULTS: There was a statistically significant increase in inspiratory muscle strength (at the end of the third month of training) as assessed by maximal inspiratory pressure (from 71 +/- 4.9 to 90 +/- 5.1 cm H(2)O [+/- SEM], p < 0.005) and 6-min walk distance (at the end of the third month of training; from 256 +/- 41 to 312 +/- 54 m; p < 0.005), a decrease in the mean Borg score during breathing against resistance (at the end of the ninth month of training), improvement in the health-related quality-of-life scores (at the end of the sixth month of training) in the training group but not in the control group. At the end of the training year, these changes were maintained; in addition, a decrease in primary health-care use and hospitalization days was observed. CONCLUSIONS: Our study shows that during IMT in patients with significant COPD, there is an increase in exercise capacity, improvement in quality of life, and decrease in dyspnea. Our study also provides evidence that long-term IMT can decrease the use of health services and hospitalization days.
The effect of a 12-week high-intensity intermittent exercise program on fiber type composition and the oxidative capacity of rectus femoris skeletal muscle from 20 male Wistar rats (Trained, n = 10; Sedentary, n = 10) was histochemically determined. The training exercise program was developed in a motorized treadmill. It consisted of four running bouts of 2 min duration at 48 m/min, alternated with recovery intervals of 4 min. Training increased relative cross-sectional area of oxidative fibers (I, IIA, IIX) and decreased the same parameter in type IIB non-oxidative fibers (P < 0.001). Our results suggest that this type of strength exercise program is enough to induce changes in muscle fiber composition. This opens a possibility to use this kind of exercise in preventing and treating muscle atrophy.
STUDY OBJECTIVES: Ghrelin is a novel growth hormone (GH)-releasing peptide that also induces a positive energy balance by decreasing fat utility and stimulating feeding through GH-independent mechanisms. We investigated whether ghrelin improves cachexia and functional capacity in patients with COPD. METHODS: This is an open-label pilot study. Human ghrelin (2 microg/kg bid) was IV administered to seven cachectic patients with COPD for 3 weeks. Food intake, body composition, muscle strength, exercise capacity, pulmonary function, and sympathetic nerve activity were examined before and after ghrelin therapy. RESULTS: A single administration of ghrelin markedly increased serum GH (21-fold). Three-week treatment with ghrelin resulted in a significant increase in mean (+/- SEM) body weight (49.3 +/- 3.6 to 50.3 +/- 3.8 kg; p < 0.05). Food intake was significantly increased during ghrelin therapy. Ghrelin increased lean body mass and peripheral and respiratory muscle strength. Ghrelin significantly increased Karnofsky performance status score and the distance walked in 6 min (370 +/- 30 to 432 +/- 35 m; p < 0.05), although it did not significantly alter pulmonary function. Ghrelin attenuated the exaggerated sympathetic nerve activity, as indicated by a marked decrease in plasma norepinephrine level (889 +/- 123 to 597 +/- 116 pg/mL; p < 0.05). CONCLUSIONS: These preliminary results suggest that repeated administration of ghrelin improves body composition, muscle wasting, functional capacity, and sympathetic augmentation in cachectic patients with COPD.
BACKGROUND AND AIMS: This pilot study measured the effects of an original low-intensity training program, called "posture-balancing-mobility" (PBM), on muscular function. METHODS: Nine non-disabled, elderly (74.3 +/- 6 years) subjects were trained with the PBM technique for 11 weeks (2 sessions per week). Mean power and fatigue index parameters were measured using an isokinetic dynamometer before and after training and compared with those recorded in another group of 9 elderly (71.1 +/- 4.3 years) subjects, who had performed aquatic exercises during the same period and with the same frequency. RESULTS: The mean power of the knee extension muscles increased slightly but significantly on the dominant (15.6%, p<0.05) and non-dominant sides (13.4%, p<0.05) in the PBM group, with no significant fatigue index variation. None of the parameters changed significantly for the aquatic group, and comparison of variations obtained in the two groups showed no significant difference between their respective effects. CONCLUSIONS: Although the results showed slightly enhanced strength production in the PBM group, the low statistical power does not allow conclusions about the impact of this type of training intervention in its current form. Nevertheless, this pilot study provides some indication of the benefits that can be obtained from such an individualized approach. Its efficiency would most likely be improved by further exploration of the minimal threshold of intensity required for strength exercises and by measurement of its effect on functions involving neuromuscular parameters, such as balance or gait.
Aging is accompanied by gradual but progressive reductions in the secretion of testosterone and growth hormone in men, and by alterations in body composition and functional capacity that, to some degree, undo the effects of puberty. Preventing or reversing these changes with the use of trophic factors, including androgens, growth hormone, and growth hormone secretagogues, is an appealing prospect, but documenting the effectiveness of these interventions and their benefits and risks has proven to be a difficult undertaking that is far from complete. Small-scale clinical studies have shown that it is practicable to boost growth hormone and IGF-1 levels for periods of up to 12 months, and testosterone for up to 36 months, to reverse at least some age-related changes in body composition. Information regarding the effects of these interventions on strength, exercise capacity, and the ability to perform activities of daily living is still sparse, and additional reports from recently completed or currently ongoing clinical trials will not provide sufficient data to make firm conclusions. From the limited information currently available, androgen supplementation may be of benefit in some men aged more than 65 years, particularly in men with low serum testosterone levels (< 2 ng/mL). In this group, supplemental androgen therapy would be expected to increase lean body mass, bone mass, and possibly strength. In older men with testosterone levels between 2 and 3.5 ng/mL, some benefit might result from androgen supplementation, but it is not yet clear whether the benefits outweigh the risks. For men in this category, one might consider a 6- to 12-month trial of therapy after a full discussion and explicit consent, followed by a reassessment of the value of ongoing treatment. The even more limited data on growth hormone or growth hormone secretagogue interventions in aging do not support their general clinical use in healthy older men. Growth hormone is much more expensive than testosterone and is not covered by insurance for off-label uses. Patients who persistently seek a trial of therapy should be encouraged to enroll in a study if one is locally available. All of the growth hormone studies reported to date have focused, generally for reasons of safety, on healthy and robust groups of older subjects, men in whom the need for intervention is least compelling and in whom the functional effects of treatment may be the most difficult to observe. Phase II studies of intermediate size and duration examining prefrail groups of elderly who are at greater risk for functional loss and who stand to benefit the most from either preventive or restorative interventions are underway but are limited to the intermediate outcomes of body composition, strength, and function. Trials designed to assess clinically relevant final outcomes, such as falls, fractures, and institutionalization, are of necessity large-scale, long-term, and expensive. Support for larger phase III studies of growth hormone is unlikely to be forthcoming until the phase II studies are completed and show further promise. A multicenter clinical trial of testosterone is currently being planned under the joint sponsorship of the National Institute on Aging, the Veterans Health Administration, and industry, aimed at assessing the effects of testosterone on the risk for falls and fractures. The results of this trial and other large clinical trials should help to better define the balance of benefits and risks of trophic factor intervention in normal older men.
It is interesting to ascertain the adaptive reaction of rat neuromuscular junctions (NMJ) of muscle fibers of different types to a chronic physical load. We examined ultrastructural changes in NMJ following both static load (pre- and postnatal ontogenesis of Wistar rats till a 2 month age took place under a constant rotation on the centrifuge at hypergravity conditions 2G), and after three kinds of dynamic loads (1/run on treadmill with a speed 35 m/min for 6 wks, 10-60 min/day; 2/swimmings, each 10 hrs/day for 10 days; 3/strength exercises on a vertical treadmill with load for 6 wks). Differences in NMJ reaction of muscle fibers of the same type to various loads were established. A low secretory activity of axonal terminals of type I muscle fibers of m. soleus was shown after the static load. The dynamic load (run) is accompanied with a high secretory activity of axonal terminals in m. soleus type I muscle fibers and of some axonal terminals of m. quadriceps femoris IIB type muscle fibers after strength exercises; the secretory activity of axonal terminals of m. quadriceps femoris IIA and IIB types muscle fibers is expressed in a lesser degree after swimming. The NMJ ultrastructure remodelling (terminal renewal) of type I muscle fibers of the 2 month old control rats increases after static and dynamic (run) loads. Some correlations between different kinds of physical load, muscle fiber type and the degree of NMJ ultrastructure transformation have been shown.
OBJECTIVE: To investigate the short- and medium-term (ie, at 1-y follow-up) effects of a hospital-based body weight reduction (BWR) program lasting 3 weeks in severely obese individuals. DESIGN: Longitudinal, clinical intervention study entailing energy-restricted diet, tailored aerobic-strength exercise, psychological counselling and nutritional education during a 3-week period followed by 49 weeks of indirect supervision at home. SUBJECTS: In all, 45 women and 19 men aged 30.2 +/- 7.2 y (mean +/- s.d.) with severe obesity (BMI: 41.3 +/- 4.3 kg/m(2)), classified as weight losers (final < initial weight) and regainers (final> or =initial weight). INTERVENTIONS: Body composition, physical performance and cardiovascular risk factors before and after the BWR program and at follow-up. RESULTS: The large majority of the experimental subjects obtained a clinical success after the 1-y period, and the rate was higher in females (n = 37/45, ie, 82.2%) than in males (n = 11/19, ie, 57.9%). At follow-up, weight losers had higher percent fat-free mass, muscle strength, HDL-cholesterol and self-reported physical activity level and lower total cholesterol and glucose levels than weight regainers (P < 0.05-0.01). Males displayed significantly larger fat-free mass losses than females at post-BWR and at follow-up. CONCLUSIONS A 3-week hospital-based integrated BWR program resulted in a high rate of clinical success in severely obese individuals at 1-y follow-up (particularly in females), that was associated with increased levels of self-reported physical activity and improved muscle strength and lipid profile. Further research is needed to establish the long-term effects (ie, at 2-5 y) associated to this treatment.
The aim of this study was to evaluate the long-term outcome of an outpatient pulmonary rehabilitation programme (PRP) in patients with chronic airway obstruction (CAO). In 61 CAO patients (35 asthmatics and 26 chronic obstructive pulmonary disease (COPD)) lung and respiratory muscle function, exercise tolerance (by symptom limited cycloergometer and walking tests), dyspnoea (Borg scale, visual analogue scale (VAS), baseline and transitional dyspnoea index (BDI and TDI, respectively)) and quality of life (St George's Respiratory Questionnaire (SGRQ)) were assessed at baseline (to), at discharge (t1) and 12 months postdischarge (t2). Preprogramme and post-programme hospital admissions and exacerbations of disease were also recorded. In comparison with baseline, no significant change was observed in lung function tests in either diagnostic group, either at t1 or at t2. In both groups improvements in respiratory muscle strength, exercise tolerance, Borg scale and VAS reported at t1 were partially reduced at t2. Analysis of variance showed that these changes over time were similar in the two groups. Mean values of SGRQ and BDI/TDI improved at t1, and, unlike exercise tolerance, did not worsen at t2. However, a clinically relevant difference in SGRQ between t2 and to was reported only in 56% of asthmatics and 52% of COPD patients. Compared with the preceding 2 yrs, in the year following PRP, hospital admissions and disease exacerbations decreased significantly in both diagnostic groups. Regardless of diagnosis, patients with chronic airway obstruction who underwent an outpatient pulmonary rehabilitation programme maintained an improved quality of life 12 months postdischarge despite a partial loss of the improvement in exercise tolerance.
PROBLEM: There is a great need to expand current knowledge of the various functional capacity measurements used in the rehabilitation of chronic low back pain (CLBP) patients. The literature on these patients reports that mobility, endurance, trunk strength and lifting capacity decrease during the process of chronicity. Chronically disabled patients appear to have lower functional capacity than asymptomatic persons. METHODS: Our study group consisted of 90 disabled CLBP patients (44 female, 46 male; average age 42 years) who underwent a multidisciplinary 8-week daily treatment program of functional restoration with behavioral support (instruction, endurance training, strength exercises, behavioral and treatment to facilitate return to work therapy). Initially these patients where compared with 107 asymptomatic persons (44 female, 63 male, average age 41 years). The patients were investigated before and after treatment, and at intervals of 6 and 12 months. The reliability of the functional measurements was evaluated by interrater comparison. Physical assessment included a medical examination (mainly diagnosis of radicular or nonradicular pain), changes in the lumbar spine revealed by X-ray studies according to Herron and Turner, rating of physical impairment according to Waddell, flexibility, length of hamstrings muscles (SLR), test of power and endurance of trunk movement by standardized exercises according to the Swiss group of Spring and isokinetic measurements (LIDO Back), tests of lifting capacity (LIDO Lift), and (in part) of general endurance on a cycle ergometer (CASE 15 Marquette). RESULTS: Physical findings showed that mobility was reduced substantially in patients suffering from back pain due to reduced SLR (shortened hamstrings) and decreased spinal mobility. Patients also demonstrated significant reductions in their ability to perform lifting tasks in comparison to healthy individuals. The results of trunk flexion showed no significant differences between patients and the control group, whereas the ability to perform trunk extension was much better in the control group. In principle we found the same results with isokinetic measurements as in the exercises without machines. Cardiovascular endurance was also much better in the control group than it was in the back pain patients. At the end of the treatment program all physical deficits were improved significantly. In many cases performance was comparable with that of the control group. With time, however, training effects gradually decreased. The success of treatment (return to work, absence from work, pain reduction, use of medical care) was independent of the functional status of the patients before and after treatment. CONCLUSION: Study results showed that physical capacity in disabled patients with low back pain is substantially reduced in comparison to persons who do not suffer from back pain. The only exception was in trunk flexor strength and endurance, in which measurements did not differ between the patients and the control group. However, even CLBP- patients with long-term pain and severe physical illness can successfully improve their physical condition by participating in an active treatment program. Back extensor muscle training has to be included in physical therapy. Because of loss of condition during the time after treatment, regular monitoring of patients and their home training programs is necessary. Overall, treatment of CLBP has to include physical training and psychosocial treatment to achieve satisfactory results.
For many years, patients with multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system, have been advised to avoid exercise. MS is believed to be autoimmune in origin, mediated by activated T cells which penetrate the blood-brain barrier and attack myelin. The pathophysiology, with respect to function is an impairment of saltatory conduction, specifically, slowing of conduction speed and/or conduction block. Symptoms can temporarily worsen on exposure to heat or during physical exercise. Exercise programmes must be designed to activate working muscles but avoid overload that results in conduction block. Fatigue, often severe, affects about 85% of MS patients and, along with motor and sensory symptoms, results in decreased mobility and reduced quality of life. Physical activity and recreation are reduced in patients with MS. Before developing recommendations, physical activity patterns and the physical effects of MS should be assessed in individual patients. Patients may then be functionally classified. Physical activity can also be classified in a pyramid structure, with the most basic functions forming the base and the most integrated functions on top. The muscular fitness pyramid progresses through passive range of motion, active resistive, specific strengthening and integrated strength exercises Overall physical activity may be increased according to functional level by performing activities of daily living, incorporating inefficiencies into daily living, pursuing more active recreation and eventually developing a structured exercise programme. The importance of the proper exercise environment, balance and coordination issues and factors related to adherence are discussed.
Lung volume reduction surgery (LVRS) has been suggested as improving respiratory mechanics in patients with severe chronic obstructive pulmonary disease (COPD). We hypothesized that LVRS might lengthen the diaphragm, increase its area of apposition with the chest wall, and thereby improve its mechanical function. To determine the effect of bilateral LVRS on diaphragm length, we measured diaphragm length at TLC, using plain chest roentgenograms (CXRs), in 25 patients (11 males and 14 females) before LVRS and 3 to 6 mo after LVRS. A subgroup of seven patients (reference data) also had diaphragm length measurements made with CXRs, using films made within a year before their presurgical evaluation. Right hemidiaphragm silhouette length (PADL) and the length of the most vertically oriented portion of the right hemidiaphragm muscle (VDML) were measured. Diaphragm dome height was determined from the: (1) distance between the dome and transverse diameter at the manubrium; and (2) highest point of the dome referenced horizontally to the vertebral column. Patients also underwent spirometry, measurements of lung volumes and diffusion capacity, an incremental symptom-limited maximum exercise test, and measurements of 6 min walk distance (6MWD) and transdiaphragmatic pressures during maximum static inspiratory efforts (Pdimax sniff) and bilateral supramaximal electrophrenic twitch stimulation (Pditwitch) both before and 3 mo after LVRS. Patients were 58 +/- 8 yr of age, with severe COPD and hyperinflation (FEV1 = 0.68 +/- 0.23 L, FVC = 2.56 +/- 7.3 L, and TLC = 143 +/- 22% predicted). Following LVRS, PADL increased by 4% (from 13.9 +/- 1.9 cm to 14.5 +/- 1.7 cm; p = 0.02), VDML increased by 44% (from 2.08 +/- 1.5 cm to 3.00 +/- 1.6 cm, p = 0.01), and diaphragm dome height increased by more than 10%. In contrast, diaphragm lengths were similar in subjects with CXRs made before LVRS and within 1 yr before evaluation. The increase in diaphragm length correlated directly with postoperative reductions in TLC and RV, and also with increases in transdiaphragmatic pressure with maximal sniff (Pdimax sniff), maximal oxygen consumption (V O2max), maximal minute ventilation (V Emax), and maximum voluntary ventilation following LVRS. We conclude that LVRS leads to a significant increase in diaphragm length, especially in the area of apposition of the diaphragm with the rib cage. Diaphragm lengthening after LVRS is most likely the result of a reduction in lung volume. Increases in diaphragm length after LVRS correlate with postoperative improvements in diaphragm strength, exercise capacity, and maximum voluntary ventilation.
OBJECTIVE: To measure lumbar extensor strength in overweight (OVW) and nonoverweight (NOVW) elderly adults before and after resistance exercise training (RX). DESIGN: Descriptive, comparative study. SETTING: University-based wellness center and research facility. PARTICIPANTS: Eighty-four adults (age range, 60-83 y) were placed into 1 of 2 groups based on body mass index (BMI): control (NOVW; mean BMI, 22.5 kg/m(2)) or OVW (mean BMI, 29.2 kg/m(2)). Subjects were then randomly assigned to either a resistance exercise (RX) or nonexercising group. INTERVENTION: Six months of total body RX and isolated lumbar extension exercise. MAIN OUTCOME MEASURES: Body composition, isometric lumbar extension strength, and 1-repetition maximum for each of the training exercises. RESULTS: Upper-body strength increased by 18.3% and 17.2% for the NOVW-RX and OVW-RX groups, respectively. Lower-body strength increased by 12.7% and 19.5% for the NOVW-RX and OVW-RX groups, respectively. At baseline, the OVW participants had greater total lumbar extension strength (1067 Nm vs 714 Nm) compared with the NOVW participants (P<.05). When expressed per kilogram of fat-free mass, there were no differences in baseline total lumbar extension strength. After RX, lumbar extension strength increased by 58% and 34% for the NOVW-RX and OVW-RX groups, respectively (P<.05). No changes in lumbar extension, upper- or lower-body strength were noted for the nontraining groups. CONCLUSIONS: OVW subjects were found to have greater absolute and similar relative, upper-body, lower-body, and lumbar extension strength at baseline when compared with their NOVW counterparts. Also, isolated lumbar extension exercise was effective in improving lumbar extensor strength in OVW and NOVW persons.