Association of spinal curve deformity and back extensor strength in elderly women with osteoporosis in Japan and the United States.

UNLABELLED: The difference in the shape of sagittal spinal curvature and distribution of vertebral fractures in women of comparable age with osteoporosis from Japan and the United States with different cultures and lifestyles was identified. Back extensor strength was significantly associated with lumbar lordosis in Akita group, indicating the potential importance of strengthening the back extensor. INTRODUCTION: The purpose of the study was to assess the association of osteoporotic spinal deformities with back strength in elderly women in Japan and the United States. METHODS: Subjects diagnosed with osteoporosis were selected to participate prospectively. In both groups, we measured the angles of thoracic kyphosis and lumbar lordosis with plain lateral radiographs and back extensor strength. The number of vertebral fractures and the ratio of lumbar fractures to thoracic fractures are also evaluated. The level of participants' daily activities was assessed with use of comparable tests in Akita (quality-of-life score) and Minnesota (physical activity score). RESULTS: A total of 102 Japanese women residing in Akita, Japan (Akita group), and 104 white women evaluated in Rochester, MN, USA (Minnesota group), participated in this study. The angle of thoracic kyphosis and lumbar lordosis was higher in the Minnesota group than in the Akita group. The ratio of lumbar fractures to thoracic fractures was higher in the Akita group than in the Minnesota group. In the Akita group, multiple regression analysis revealed that the angle of lumbar lordosis correlated significantly with back extensor strength. CONCLUSIONS: We identified the difference in the shape of sagittal spinal curvature and distribution of vertebral fractures in women of comparable age with osteoporosis from two geographic areas of the world with different cultures and lifestyles. Back extensor strength was significantly associated with lumbar lordosis in Akita group, indicating the potential importance of strengthening the back extensor for improving or maintaining lumbar lordosis.

Effect of season on physical activity score, back extensor muscle strength, and lumbar bone mineral density.

Seasonal variation in physical activity, back extensor muscle strength (BES), and bone mineral density (BMD) of the lumbar spine was studied in 65 healthy postmenopausal women. Physical activity score (PAS) was assessed with an ordinal scale (0-18); this score and the BES were obtained monthly for 2 years (25 readings). BMD values were obtained semiannually (5 readings). A periodic (cosine) regression model was fit to each subject's PAS and BES data to obtain individual estimates of the annual peak day d and the average annual range due to seasonality. There was a strong (P less than 0.001) seasonal pattern in physical activity; August 3 was the average peak day, and the seasonal range was 2.0 PAS units. There was modest (P = 0.047) seasonality in BES; June 6 was the estimated peak day, and the seasonal range was 8.22 pounds (about 7% of the 0.002), and the highest monthly average BMD was in August. This seasonal range of 1.4% is larger than the average annual decline with age in BMD observed in longitudinal studies of postmenopausal women. The results of this study have important implications for the planning of longitudinal studies involving changes in physical activity or bone mass in geographic areas with diverse seasons.

Three-year controlled, randomized trial of the effect of dose-specified loading and strengthening exercises on bone mineral density of spine and femur in nonathletic, physically active women.

The objectives of this study were to evaluate (1) the effect of spinal muscle strengthening by loading exercises on the bone mineral density (BMD) of the spine, and (2) the effect of upper extremity loading exercises on the BMD of the midradius and femur in healthy, premenopausal women. The study design was a randomized, controlled trial of 3 years' duration. Ninety-six healthy, premenopausal, white women aged 30-40 years participated; 67 completed the study. All subjects were in good health (normal menses) and were active, but not athletic (that is, not involved in a regular sport activity). Subjects were randomized to an exercise or control group. The exercise group performed a supervised, non-strenuous, weight-lifting exercise program. Exercise performance was supervised once a week at the medical facility. In addition, the subjects performed the exercises twice a week on their own. Dietary calcium intake was to be maintained at 1,500 mg/day in both groups. Bone density was measured at the lumbar spine and hip with dual-energy X-ray absorptiometry at 0, 1, and 3 years. BMD of the midradius was measured with single photon absorptiometry. Measurements of muscle strength were obtained at baseline and every 3 months for 3 years. Maximal oxygen uptake was measured, and the level of physical activity was recorded. Compliance with the exercise program was excellent during the first year of the study, but decreased thereafter. At the end of 3 years, subject withdrawal was about 34% from the exercise group and about 22% from the control group (total subject withdrawal was about 30%). Muscle strength in the exercise group increased significantly at all involved skeletal sites (p values all < 0.001). There was a modest positive correlation between the BMD of Ward's triangle with spinal flexor strength (r = 0.32, p = 0.008) and with grip strength (r = 0.38, p = 0.001). Comparing study groups, we found no significant effect of the loading and nonstrenuous strengthening exercises in the exercise group or free physical activity group (our control group) on BMD at the spine, hip, or midradius measurement sites. In active, but not athletic premenopausal women, additional moderate weight-lifting exercises showed no significant effect on BMD.

Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women.

The long-term protective effect of stronger back muscles on the spine was determined in 50 healthy white postmenopausal women, aged 58-75 years, 8 years after they had completed a 2 year randomized, controlled trial. Twenty-seven subjects had performed progressive, resistive back-strengthening exercises for 2 years and 23 had served as controls. Bone mineral density, spine radiographs, back extensor strength, biochemical marker values, and level of physical activity were obtained for all subjects at baseline, 2 years, and 10 years. Mean back extensor strength (BES) in the back-exercise (BE) group was 39.4 kg at baseline, 66.8 kg at 2 years (after 2 years of prescribed exercises), and 32.9 kg at 10 years (8 years after cessation of the prescribed exercises). Mean BES in the control (C) group was 36.9 kg at baseline, 49.0 kg at 2 years, and 26.9 kg at 10 years. The difference between the two groups was still statistically significant at 10 year follow-up (p = 0.001). The difference in bone mineral density, which was not significant between the two groups at baseline and 2 year follow-up, was significant at 10 year follow-up (p = 0.0004). The incidence of vertebral compression fracture was 14 fractures in 322 vertebral bodies examined (4.3%) in the C group and 6 fractures in 378 vertebral bodies examined (1.6%) in the BE group (chi-square test, p = 0.0290). The relative risk for compression fracture was 2.7 times greater in the C group than in the BE group. To our knowledge, this is the first study reported in the literature demonstrating the long-term effect of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women.

Postmenopausal spinal osteoporosis: physical therapy and rehabilitation principles.

In this communication the physical therapy and rehabilitation measures utilized in the management of patients with spinal osteoporosis are discussed. The bone loss and the subsequent bone disease that occur in some older persons, and especially in postmenopausal women, call for special physical therapeutic measures. One should be cautious about prescribing exercises, for some may predispose the spine to undue sprain and strain. This principle applies to any exercise program, whether therapeutic or recreational.

Effect of back-strengthening exercise on posture in healthy women 49 to 65 years of age.

OBJECTIVE: To evaluate the effect of back-strengthening exercise on posture in 60 healthy estrogen-deficient women. DESIGN: The 60 study subjects were randomly assigned to either an exercise or a control group, and various factors were assessed at time of enrollment in the study and at 2-year follow-up. MATERIAL AND METHODS: The 32 women in the exercise group were instructed in progressive back-strengthening exercises, whereas the 28 women in the control group had no exercise prescription and were asked to continue their usual physical and dietary activities. At baseline and 2-year follow-up examinations, back extensor strength was measured with a strain-gauge dynamometer, and lateral roentgenograms of the thoracic and lumbar areas of the spine were obtained to measure the angles of thoracic kyphosis, lumbar lordosis, and sacral inclination. The changes in radiographic measurements and back extensor strength were analyzed statistically. RESULTS: Back extensor strength increased significantly in both the exercise and the control groups, but no radiographic measurements were significantly different between these groups. The significant increase in back extensor strength in both groups of healthy women suggested that the original grouping did not accurately reflect the amount of exercise. Thus, the 60 subjects were reclassified for comparison on the basis of increase in back extensor strength--27 with more than or equal to the mean increase of 21.1 kg and 33 with less than 21.1 kg. Furthermore, each of these groups of subjects was subdivided on the basis of degree of thoracic kyphosis. Among the subjects with substantial thoracic kyphosis, those with a significant increase in back extensor strength had a significant decrease in thoracic kyphosis (-2.8 +/- 4.2 degrees; P = 0.041), whereas those with a small increase in strength had a nonsignificant increase in thoracic kyphosis (1.8 +/- 5.3 degrees). The increase in back extensor strength did not seem to affect mild degrees of kyphosis. CONCLUSION: Increasing the back extensor strength in healthy estrogen-deficient women helps decrease thoracic kyphosis.

Posture Training Support: preliminary report on a series of patients with diminished symptomatic complications of osteoporosis.

Back supports are often used to minimize or prevent complications of osteoporosis. Nevertheless, the few related studies to date reveal that the currently available thoracolumbar and lumbosacral supports have substantial limitations, including (1) poor compliance because of discomfort or restricted motion, (2) expense, (3) unacceptable cosmetic and aesthetic appearance, and (4) medical contraindications to the use of rigid supports. We report the initial results of a clinical trial of the Posture Training Support (a thoracolumbar support) in 29 women and 1 man with osteoporosis or osteopenia of the spine (ages 37 to 87 years), who were referred because of back pain or kyphosis. We hypothesize that this inexpensive, unobtrusive device promotes improvement in posture and reduces back pain either by acting as a proprioceptive reinforcer or by producing a force posteriorly below the inferior angles of the scapulae and thus decreasing the anterior compressive forces that are commonly exerted on the spine. Among the 23 patients who reported substantial back pain before use of the support, relief of the pain was "significant" in 17 and minimal in 6. Nineteen patients noted improvement in their posture. No patient reported worsening of back pain or posture, nor did any patient discontinue use of the device for cosmetic reasons, discomfort, or other complaints. Four patients previously could not tolerate other back supports, and 14 had previously used other supports without substantial improvement. These preliminary results suggests that the Posture Training Support may be of considerable symptomatic and prophylactic value to patients with osteoporosis who cannot tolerate conventional back supports.

Rehabilitation techniques for patients with amyotrophic lateral sclerosis.

Rehabilitation techniques for the management of patients with amyotrophic lateral sclerosis are aimed at maintaining the patients at their optimum functional levels for as long as possible and at preventing complications secondary to disuse of muscles and immobilization. A functional staging of patients is proposed which is helpful in categorizing them in reference to the type of rehabilitative techniques required and the kinds of assistive devices needed.

Vertebral compression fractures sustained during golfing: report of three cases.

Considerable concern has been expressed about the type and level of exercise that are safe for women with osteopenia and osteoporosis; however, published information on the effect of golfing on the osteoporotic spine is meager. We describe three postmenopausal patients with acute compression fractures of the vertebrae that occurred during midswing while golfing. These healthy, active women were long-term golfers; their ages at the time of the trauma were 63, 58, and 66 years. In one patient (case 1), osteoporosis was diagnosed before the golf-related injury. The two other patients (cases 2 and 3) sought medical attention after the trauma and were found to have osteoporosis. The bone mineral density of the lumbar vertebrae (L2-4) in the three patients at the time of or shortly after the trauma was as follows: case 1, 0.77 g/cm2 (3rd percentile of normal, corrected for age); case 2, 0.63 g/cm2 (less than 1st percentile of normal, corrected for age); and case 3, 0.69 g/cm2 (2nd percentile of normal, corrected for age). These findings raise the issue of the safety of golfing for women with previously diagnosed osteoporosis and for those with predisposing risk factors for the disease. Research studies of the kinematics and kinetics of the spine during the golf swing should be conducted. In the interim, a rigid back support for golfers with osteoporosis may be helpful until more conclusive evidence is available from controlled trials.

Rehabilitative operation for motor neuron disease: tendon transfer for segmental muscular atrophy of the upper extremities.

Segmental spinal muscular atrophy of adolescence is a clinical syndrome that can be distinguished from the more common forms of motor neuron disease. A patient with this syndrome who was no longer able to care for herself is described. After selective tendon transfers in her right upper extremity, she has been able to perform many of the activities of daily living. This improved function has been maintained for more than 2 years. We suggest that transfer of tendons and muscles may be indicated in selected patients with slowly progressive muscular atrophy.

Tension myalgia of the pelvic floor.

The clinical picture in and efficacy of physical treatment for pelvic floor myalgia were reviewed. The medical records of patients having a diagnosis of pyriformis syndrome, coccygodynia, levator ani spasm syndrome, proctalgia fugax, or rectal pain who had been seen at the Mayo Clinic and treated in the Department of Physical Medicine and Rehabilitation from 1970 through 1975 were retrieved. Adequate information and follow-up were available for 94 patients. Seventy-eight patients were women and 16 were men, whose ages ranged from 26 to 72 years. All patients had tenderness of the pelvic floor muscles on rectal examination. The most common associated findings were poor posture, deconditioned abdominal muscles, and generalized muscle attachment tenderness. The most effective therapeutic regimen was a combination of rectal diathermy, Thiele's massage, and relaxation exercises. Of the 94 patients, 30 had complete resolution of their symptoms, 19 had marked improvement, 17 had moderate improvement, and 14 had mild improvement. Only 14 patients had no change and 1 patient was worse after treatment.

Effect of back supports on back strength in patients with osteoporosis: a pilot study.

OBJECTIVE: To determine the effect of application of back supports on back strength in subjects with osteoporosis. DESIGN: In a prospective, randomized, controlled study, we compared compliance and evaluated changes in back strength in 45 women with osteoporosis who were older than 40 years of age and were randomly assigned to one of three groups: (1) postural exercise only, (2) postural exercise and a conventional thoracolumbar support, or (3) postural exercise and a Posture Training Support (PTS) (a weighted kypho-orthosis). MATERIAL AND METHODS: Of the 45 study participants, 15 were assigned to a PTS group, 15 to conventional thoracolumbar support, and 15 to no orthosis. All subjects were instructed in basic body mechanics and postural exercises. Back extensor strength, grip strength, and patient's physical activity were measured at baseline and at subsequent 8-week intervals for a 16-week period. Each patient's compliance during the study period was also recorded. RESULTS: compliance was poor among the thoracolumbar group; only 5 of the 15 subjects completed the study (P<0.001), in comparison with 11 of the 15 patients in the control group and all 15 in the PTS group. Analysis revealed statistically significant mean increases in back strength in the PTS group (23%) and the control group (13%) and a nonsignificant increase in the thoracolumbar group (15%), although poor compliance in the thoracolumbar group yielded insufficient power to detect a significant difference in this group. No statistically significant difference was found between the improvements in the PTS and control groups, possibly because of the small sample size in this pilot study. One patient who wore the PTS for only 4 hours a day rather than 8 hours had the largest percentage increase in back extensor strength of this group (78%). At 16 weeks, decreases in back strength of more than 5% below the initial measurements were noted in 1 of 11 subjects (9%) who completed the control arm of the study, 2 of 14 (14%) who completed the PTS arm, and 2 of 5 (40%) who completed the thoracolumbar arm. CONCLUSION: Compliance with use of the PTS was better than that with the thoracolumbar support. Back extensor strength may increase in patients who comply with the PTS and postural exercise program. We caution, however, that this pilot study requires replication in a larger series to determine the clinical and statistical generalizability of these findings to a wider population.

Lumbar spondylolisthesis: a rational approach to conservative treatment.

Forth-seven patients with symptomatic back pain secondary to spondylolisthesis who were not surgical candidates were instructed in a treatment program that included flexion or extension or combined flexion-extension exercises. At follow-up, symptomatic changes were correlated with the type of exercise program. Patients treated with flexion-type exercises were less likely to require use of back supports, require job modification, or limit their activities because of pain. Although surgical treatment of spondylolisthesis has been outlined in current literature, conservative programs have not been well defined. Factors aggravating pain and a specific program for pain reduction are discussed.

Efficacy of nonloading exercises in prevention of vertebral bone loss in postmenopausal women: a controlled trial.

A considerable increase in muscle strength and bone mass can be achieved in young adults through athletic exercise programs. We studied a less demanding nonloading exercise program for the back extensor muscles in postmenopausal women who were not on estrogen therapy. We randomly assigned 65 healthy Caucasian women without evidence of or risk factors for osteoporosis into an exercise group and a control group. The strength of the back extensor muscles and bone mineral density of the lumbar spine were measured at baseline and every 6 months for 2 years. In addition, a physical activity score was determined. Compliance was assessed by regular interviews and review of diaries. During the 2-year study, the mean rates of bone loss in the two groups were not statistically different. The strength of the back extensor muscles increased in both groups but significantly more (P = 0.002) in the exercise group. We conclude that postmenopausal bone loss is unaffected by a modest exercise program despite an increase in muscle strength. Nonloading muscle exercise may be ineffective in retarding vertebral bone loss in ambulatory, healthy postmenopausal women.

Can strong back extensors prevent vertebral fractures in women with osteoporosis?

OBJECTIVE: To determine the influence of back extensor strength on vertebral fractures in 36 women with osteoporosis. DESIGN: We conducted a cross-sectional study of female patients with osteoporosis by assessing anthropometric variables, bone mineral density, muscle strength, level of physical activity, and radiographic findings in the spine. MATERIAL AND METHODS: The 36 study subjects with osteoporosis, who ranged from 47 to 84 years of age, satisfied specific inclusion and exclusion criteria that minimized confounding factors related to pathophysiologic features, diet, and medications. A physical activity score was determined for each subject on the basis of daily physical activities relating to homemaking, occupation, and sports. RESULTS: The range of the physical activity scores-from 2 to 13-indicated that no subject was involved in unusually demanding physical activities. Bone mineral density values ranged from 0.49 to 0.92 g/cm2. Thoracic kyphosis ranged from 31.0 to 84.0 degrees. Isometric strength of the back extensor muscles ranged from 7.3 to 34.0 kg. Statistical analysis demonstrated a significant negative correlation between the strength of the back extensor muscles and thoracic kyphosis. Significant negative correlations were also found between back extensor strength and the number of vertebral compression fractures and between bone mineral density and the number of vertebral fractures. CONCLUSION: The negative association between back extensor strength and both kyphosis and number of vertebral fractures suggests that increasing back strength may prove to be an effective therapeutic intervention for the osteoporotic spine. In persons with stronger back muscles, the risk of vertebral fractures will likely decrease.

Physical activity, but not aerobic capacity, correlates with back strength in healthy premenopausal women from 29 to 40 years of age.

The correlation of muscle strength at various sites of the axial and appendicular skeleton with physical activity and aerobic capacity was assessed in women 29 to 40 years old. Muscle strength of the spine and upper extremities was determined with strain gauges in 96 healthy white women, and power grip was used as an indicator of upper extremity strength. The physical activity score, which reflected the level of daily weight-bearing activity and was based on a standardized scale, ranged from 3 to 15. Maximal oxygen uptake (aerobic capacity) was measured in 69 of the 96 subjects. The mean values for maximal oxygen uptake were 1.9 liters/min and 27.9 ml/kg per minute when normalized for weight. In general, muscle strength was significantly correlated between axial and appendicular sites; thus, the axial musculature usually represents overall muscle strength. Maximal oxygen uptake in milliliters per kilogram per minute was not correlated with back extensor strength or upper extremity strength. Physical activity score was significantly correlated with back extensor strength but not with maximal oxygen uptake (aerobic capacity) either in liters per minute or in milliliters per kilogram per minute. Thus, maximal oxygen uptake is an invalid marker for level of daily weight-bearing physical activity.

A useful technique for measurement of back strength in osteoporotic and elderly patients.

Improvement of back extensor strength (BES) can be used as a therapeutic method for patients with chronic back pain and osteoporosis. The method of evaluation must be reliable and accurate without compromising the condition of the patient. We report the development of a back isometric dynamometer (BID-2000) designed specifically by two of us to address these concerns in elderly patients with osteopenia or osteoporosis. As the demographics of the general population change, increasing numbers of patients will need the type of monitoring that the BID-2000 provides. Aging has been shown to cause a reduction in the number of functional muscle motor units. To examine this effect on BES, we tested 50 normal, healthy women who were 30 to 79 years old. Proper testing of BES in patients with fragile vertebrae should include isometric measurement in the prone position, maneuverability of the device to allow comfortable positioning of the patient, and simplicity of technique to minimize repetitious performance of maximal contraction. The BID-2000 incorporates each of these features and also provides meaningful results inexpensively. The device offers a safe, reliable (coefficient of variation = 2.33%), and valid (P = 0.001) method of evaluation. The results of our study demonstrated moderate, steady reduction of BES with increasing age and with each successive decade.

Relationship between bone mineral density of spine and strength of back extensors in healthy postmenopausal women.

We determined the bone mineral density of the lumbar spine and the strength of back extensors in 68 healthy postmenopausal Caucasian women. Bone mineral density of the second to fourth lumbar vertebrae was measured by dual-photon absorptiometry, and back extensor strength was determined with use of a strain-gauge dynamometer. The bone mineral density percentile ranged from 2 to 99%, and back extensor strength ranged from 37 to 145 lb. Statistical analysis demonstrated a significant positive correlation (P = 0.004) between bone mineral density and back extensor strength, even when bone mineral density was corrected for age. Bone mineral density was also significantly positively correlated with body weight (P = 0.003), height (P = 0.001), and arm span (P = 0.008). These data suggest that the strength of back muscles may contribute to the bone mineral density of vertebral bodies.

Correlation of trunk muscle strength with age in children 5 to 18 years old.

OBJECTIVE: To determine the correlation of trunk muscle strength with age in children and the effect of gender on changes in trunk muscle strength. MATERIAL AND METHODS: Strength of the back extensors and back flexors was evaluated in 137 healthy boys and 109 healthy girls who were 5 to 18 years old. Anthropometric determinations of height and weight were done in all study subjects. Maximal back muscle strength was measured with an isometric dynamometer (BID-2000). Standardized positioning techniques were used to allow comparison with the follow-up evaluations. RESULTS: Regression analysis revealed significant increases in trunk strength with increasing age; the strength of the boys began diverging from that of the girls at age 9 to 10 years. Back extensor strength also increased with increasing height and weight, and expected differences were noted between boys and girls. Strength levels ranged from 80 to 774 newtons (18 to 174 lb). Mean back extensor strength in 2-year age intervals ranged from 153 newtons (34.4 lb) in girls 5 to 7 years old to 504 newtons (113.3 lb) in boys 16 to 18 years of age. (Each newton is equal to 0.2248 lb.) CONCLUSION: Results of this study demonstrated that age, height, and weight are all important predictors of trunk strength in children, and the effects of these factors are modulated by gender.

Bone mass and muscle strength in female college athletes (runners and swimmers).

OBJECTIVE: To determine whether female college athletes had increased muscle strength and bone mass in comparison with age-matched nonathletic female subjects and, if so, whether participation in weight-bearing versus non-weight-bearing exercise made a difference. MATERIAL AND METHODS: We performed a comparative statistical analysis of the bone mineral density (BMD) of the total body, lumbar spine, and femoral neck, maximal oxygen uptake (VO2max), muscle strength, and level of physical activity in 21 runners, 22 swimmers, and 20 control subjects. The study participants were female college students, 18 to 24 years old, who had had more than 8 normal menstrual cycles during the past year. RESULTS: Statistical analyses showed significantly higher VO2max in the two athletic study groups than in the control subjects (P < 0.0001). No significant difference in BMD was noted among the three groups. Total body BMD (r = 0.30; P = 0.02) and femoral neck BMD (r = 0.39; P = 0.002) were positively correlated with weight-bearing activity but not with non-weight-bearing activity. VO2Max (an index of physical fitness) was positively correlated with femoral neck BMD (r = 0.33; P = 0.009) and trochanteric BMD (r = 0.29; P = 0.021). Shoulder muscle strength (determined by isokinetic dynamometry) was positively correlated with total body BMD (r = 0.34; P = 0.007) and lumbar spine BMD (r = 0.28; P = 0.028). Swimmers had higher muscle strength in the back and upper extremities than did runners and control subjects. Hip girdle muscle strength was not significantly different among the three groups. Total body BMD had a positive correlation with percentage of body fat and height. Lumbar spine BMD was higher in subjects who had previously used oral contraceptives. The athletes had a lower percentage of body fat, were less likely to have used oral contraceptives, and had fewer years of normal menses than did the control subjects. CONCLUSION: Our study shows that (1) total body BMD and femoral neck BMD were significantly higher in the study group that performed weight-bearing exercises than in control subjects, (2) swimming exercise had no effect on BMD, and (3) although swimming is not a bone-building exercise, it can significantly improve shoulder, back, and grip muscle strength.