Michael N. Fulton

Lumbar strengthening in chronic low back pain patients. Physiologic and psychological benefits.

The effects of exercise for isolated lumbar extensor muscles were examined in 54 chronic low-back pain patients. Subjects were randomly assigned to a 10-week exercise program (N =31) or a wait-list control group (N = 23). Results indicated a significant increase in isometric lumbar extension strength for the treatment group and a significant reduction in reported pain compared with the control group (P 0.05). Treated subjects reported less physical and psychosocial dysfunction whereas the control group increased in pain, and physical and psychosocial dysfunction. There were no concomitant changes in reported daily activity levels. These results show that lumbar extension exercise is beneficial for strengthening the lumbar extensors and results in decreased pain and improved perceptions of physical and psychosocial functioning in chronic back pain patients. However, these improvements were not related to changes in activities or psychological distress.

Quantitative assessment of full range-of-motion isometric lumbar extension strength.

The purpose of this study was to evaluate the reliability and variability of repeated measurements of isometric (IM)lumbar extension (LB EXT) strength made at differnt joint angles. Fifty-six men (age, 29.4 ± 10.7 years) and 80 women (age, 24.3 ± 9.1 years) completed IM LB EXT strength tests on 3 separate days (D1, D2, and D3). On D1 and D2, subjects completed two tests (T1 and T2) separated by a 20-to 30-minute rest interval. For each test, IM LB EXT strenth was measured at 72, 60, 48, 36, 24, 12, and 0° of lumbar extension. Mean IM strength values, within-day reliability coefficients, and test variability over the seven angles improved from D1 to D2 (D1: mean, 160.0 to 304.1 N · m, r=0.78 to 0.96, SEE = 37.6 to 46.9 N · m; D2: mean, 176.3 to 329.1 N · m, r = 0.94 to 0.98, SEE = 29.0 to 34.4 N · m). Mean strength values leveled off by D3 (174.5 to 317.0 N · m). The most reliable test results showed that the IM LB EXT strength curves were linear and descending from flexion to extension and ranged from 235.8 ± 85.2 to 464.9 ± 150.7 N · m for men (extension to flexion) and from 134.6 ± 53.2 to 237.3 ± 71.9 N. m for women. Lumbar extension strength was clearly greatest in full flexion, which is in contrat to previously reported results. One practice test was required to attain the most accurate and reliable results. These data indicate that repeated measures of IM LB EXT strength are highly reliable and can be used for the quantification of IM LB EXT strength through a range of motion.

Effect of resistance training on lumbar extension strength

Development of a new testing machine, which stabilizes the pelvis, allowed us to evaluate the lumbar extensor muscles before and after training. Fifteen healthy sub jects (29.1 ± 8 years of age) trained 1 day per week for 10 weeks and 10 healthy subjects (33.7 ± 16 years of age) acted as controls. Training consisted of 6 to 15 repetitions of full range of motion variable resistance lumbar extension exercise to volitional fatigue and periodic maximal isometric contractions taken at seven angles through a full range of motion. Before and after the 10 week training period, subjects completed a maximum isometric strength test at seven angles through a 72° range of motion (0°, 12°, 24°, 36°, 48°, 60°, and 72° of lumbar flexion). The training group significantly improved in lumbar extension strength at all angles (P ≤ 0.01). The result at 0° (full extension) showed an increase from 180.0 ± 25 Nm to 364.1 ± 43 Nm (+102%) and at 72° (full flexion) from 427.4 ± 44.1 to 607.4 ± 68 (+42%) Nm. Results from the control group showed no change (P ≥ 0.05). The mag nitude of gain shown by the training group reflects the low initial trained state of the lumbar extensor muscles. These data indicate that when the lumbar area is iso lated through pelvic stabilization, the isolated lumbar extensor muscles show an abnormally large potential for strength increase.

Resistance training prevents vertebral osteoporosis in lung transplant recipients

Background. Osteoporosis and vertebral fractures are a consequence of glucocorticoid immunosuppression therapy in lung transplant recipients (LTR). The purpose of this study was to determine the therapeutic efficacy of a 6-month program of specific resistance exercise designed to reverse glucocorticoid-induced vertebral osteoporosis. Methods. Sixteen lung transplant candidates were randomly and prospectively assigned to a group (n=8) that performed 6 months of exercise on a lumbar extensor machine or to a control group (n=8). Resistance exercise was initiated at 2 months after transplantation. Bone mineral density (BMD) of the lumbar vertebra (L2-3) was assessed using a dual-energy X-ray absorptiometer (DXA). DXA scans were performed before and 2 months after transplantation and after 6 months of lumbar extensor training or control period. Results. Lumbar BMD did not differ (P >0.05) between the two groups at study entry. Both the trained (0.63 to 0.54 g/cm2 of hydroxyapatite) and control groups (0.62 to 0.53 g/cm2 of hydroxyapatite) lost significant and comparable amounts (−14.5%) of BMD between study entry and 2 months posttransplantation. The control group lost further (P ≤0.05) lumbar BMD between 2 and 8 months posttransplantation (0.53 to 0.50 g/cm2 of hydroxyapatite), decreasing to values that were 19.5% less than pretransplantation baseline. Lumbar BMD in the trained group increased significantly (+9.2%) after 6 months (0.54 to 0.60 g/cm2 of hydroxyapatite) and returned to values that were within 5% of pretransplantation baseline. Conclusion. Mechanical loading associated with progressive resistance exercise, using a specific exercise that isolated the lumbar spine, was efficacious in preventing steroid-induced osteoporosis in LTR.

Resistance exercise training and alendronate reverse Glucocorticoid-Induced osteoporosis in heart transplant recipients ☆

BACKGROUND Immunosuppression therapy with bolus glucocorticoids causes regional osteoporosis in the axial skeleton of heart transplant recipients (HTR). No preventive strategy is generally accepted for steroid-induced bone loss. METHODS To determine the efficacy of an anti-osteoporosis regimen that combined a bisphosphonate agent (alendronate sodium) with the osteogenic stimulus of mechanical loading, 25 HTRs were randomly assigned either to a group that received alendronate (10 mg/day) for 6 months (ALEN; n = 8), a group that received alendronate (10 mg/day) and performed specific resistance exercises for 6 months (ALEN + TRN; n = 8) or to a non-intervention control group (CONTR; n = 9). Alendronate was initiated at 2 months after transplantation. Bone mineral density (BMD) of the total body, femur neck and lumbar spine (L-2 and L-3) was measured by dual-energy X-ray absorptiometry before and 2, 5 and 8 months after transplantation. Resistance training consisted of lumbar extension exercise (MedX) performed 1 day/week and 8 variable resistance exercises (MedX) performed 2 days/week. RESULTS Pre-transplantation BMD values did not differ among the 3 groups. BMD of the total body, femur neck and lumbar vertebra were significantly decreased below baseline at 2 months after transplantation in CONTR (-2.6 +/- 0.9%, -5.1 +/- 1.8%, -12.5 +/- 4.2%, respectively), ALEN (-2.8 +/- 0.8%, -5.3 +/- 1.6%, -12.0 +/- 3.9%) and ALEN + TRN groups (-2.7 +/- 1.0%, -5.6 +/- 2.1%, -11.2 +/- 3.7%). CONTR had further significant losses of BMD after 3 and 6 months. ALEN had no further regional BMD losses after initiation of alendronate therapy. ALEN + TRN restored BMD of the whole body, femur neck and lumbar vertebra to within 0.9%, 2.1%, and 3.4% of pre-transplantation levels, respectively. CONCLUSIONS Resistance exercise plus alendronate was more efficacious than alendronate alone in restoring BMD in HTRs. Our results indicate that anti-osteoporosis therapy in this population should include both an anti-resorptive agent as well as an osteogenic stimulus, such as mechanical loading.

Frequency and volume of resistance training : effect on cervical extension strength

Quantification of cervical extension (CERV EXT) strength is complicated by the inability to stabilize the torso and isolate the CERV EXT muscles. A newly developed machine designed to stabilize the torso and isolate the CERV EXT muscles was used to evaluate the effect of frequency and volume of resistance training on CERV EXT strength. Fifty men (age, 26 +/- 9 years; height, 174 +/- 16 cm; weight, 74 +/- 9 kg) and 28 women (age, 30 +/- 9 years; height, 152 +/- 32 cm; weight, 62 +/- 7 kg) volunteered to participate. Subjects were randomly stratified to one of four training groups or a control group (CONT, n = 19) that did not train. Each training group exercised for 12 weeks as follows; once per week using one set of dynamic exercise (DYN 1x/wk, n = 14), once per week using one set of DYN and one set of maximal isometric (IM) exercise at eight angles through a 126 degrees-range of CERV EXT (DYN-IM 1x/wk, n = 16), DYN 2x/wk (n = 19), or DYN-IM 2x/wk (n = 10). Maximal IM torque was measured at eight angles initially and after 12 weeks of training. All training groups improved CERV EXT strength (p < or = 0.05) at all angles tested compared to the CONT except for DYN once per week at 0 degree of CERV flexion. A greater increase in strength was found when the groups that trained two times a week were compared to those that trained once per week.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative assessment and training of isometric cervical extension strength

The purpose of this study was to evaluate the reliability and variability of repeated measurements of isometric cervical extension strength and determine the effect of 10 weeks of dynamic variable resistance cervical ex tension training on isometric cervical extension strength. Seventy-three subjects (age, 29 ± 12 years [mean ± SD]) completed isometric cervical extension strength tests on 4 separate days (D1, D2, D3, and D4). For each test, isometric cervical strength was measured at 126°, 108°, 90°, 72°, 54°, 36°, 18°, and 0° of cervical flexion. Between-day correlation coeffi cients over the eight angles of cervical flexion were high for D2 versus D3 (r = 0.90 to 0.96). Test variability (standard error of estimate) between D2 versus D3 was low (7.4% to 10.2% of mean) through the entire range of motion. Regression analysis showed that the iso metric cervical extension strength curve is linear and descending from flexion to extension. In a second study, 14 subjects (age, 25 ± 3 years) trained the cervical extensor muscles for 10 weeks while 10 sub jects (age, 23 ± 3 years) served as controls. Training included 8 to 12 cervical extensions to volitional fatigue, 1 day per week. The training group improved isometric cervical extension strength at six of eight angles before to after training (P ≤ 0.05). During the same time period the control group did not change. These data indicate that repeated measures of isometric cervical extension strength are highly reliable and can be used for the quantification of isometric cervical extension strength through a 126° range of motion. Also, training the cervical extensors 1 day per week can significantly increase isometric cervical extension strength through most of the range of motion.

Cross-sectional thigh components: Computerized tomographic assessment

The purpose of this study was to examine the efficacy of the Picker Synerview Fourth Generation CT Scanner in assessing cross-sectional areas of muscle, bone, and subcutaneous fat of the thigh. A secondary purpose was to resolve individual muscle bellies using the CT scanner and to determine the effects of body composition in isolating those muscles. Both limbs of one cadaver were used to compare actual cross-sectional areas with the CT images. Each limb was dissected and photographed. Accuracy of repeated measurements was assessed using human volunteers. Absolute and percent error between the CT measurements and the measurements of the cross-sectional areas differed most at the bone. No differences were found between repeat scans. CT images and photographic measurements of individual muscles were generally quite similar, as assessed by absolute and percent error. The gracilis and sartorious were reasonably well defined in those individuals with more than 8% body fat. The results are discussed in terms of possible applications of the CT scanner in sports medicine research.

Isometric torso rotation strength: Effect of training frequency on its development

OBJECTIVE To examine training frequencys effect on torso rotation muscle strength. DESIGN The study followed a pretest-posttest randomized-group design. SETTING University laboratory. PATIENTS Subjects, 33 men (age 30 +/- 11yr) and 25 women (age 28 +/- 10yr) with no history of low back pain, volunteered to participate in the study and were tested for isometric (IM) torso rotation strength before (T1) and after (T2) 12 weeks of training. Measurements of maximal voluntary IM torso rotation torque (N.m) were made through a 108 degrees range of motion (54 degrees, 36 degrees, 18 degrees, 0 degree, -18 degrees, -36 degrees, -54 degrees). Subjects were stratified by peak torque at T1, and randomized to a nonexercising control group (C, n = 10), or groups that trained once a week (1x/wk, n = 16), twice a week (2x/wk, n = 17), or three times a week (3x/wk, n = 15); and all groups were similar in strength. INTERVENTIONS Training consisted of 8 to 12 repetitions of full range dynamic variable resistance exercise to volitional fatigue, for both left and right rotation. MAIN OUTCOME To determine the best training frequency for the development of torso rotation strength. RESULTS Relative improvements (average increase in strength gained at each angle) for the training groups were 4.9%, 16.3%, and 11.9% for the 1, 2, and 3x/wk groups, respectively. The 1x/wk group did not increase in IM torso rotation strength compared to the control group at any angle. Both the 2 and 3x/ wk groups increased their IM torso rotation strength compared to the control group at all but one angle. There were no significant differences in IM torso rotation strength between the groups that trained 2 or 3x/wk. During the training period, the 2 and 3x/wk groups increased their dynamic training load significantly more than the 1x/wk group. CONCLUSIONS Posttraining dynamic strength was not different between training frequencies of 2 and 3x/wk. Therefore, training the rotary torso muscles 2x/wk is recommended.

Limited range-of-motion lumbar extension strength training

The purpose of this study was to evaluate the effect of limited range-of-motion (ROM) resistance training on the development of lumbar extension strength through a 72 degrees ROM. Thirty-three men and 25 women (age = 30 +/- 11 yr) were randomly assigned to one of three training groups or a control group (C; n = 10) that did not train. Training was conducted once per week for 12 wk and consisted of one set of 8-12 repetitions of variable resistance lumbar extensions until volitional fatigue. Group A (n = 18) trained from 72 degrees to 36 degrees of lumbar flexion; group B (n = 14) from 36 degrees to 0 degree of lumbar flexion; and group AB (n = 16) from 72 degrees to 0 degree of lumbar flexion. Prior to and after training, isometric lumbar extension torque was assessed at 72 degrees, 60 degrees, 48 degrees, 36 degrees, 24 degrees, 12 degrees, and 0 degree of lumbar flexion. Analysis of covariance showed that groups A, B, and AB increased lumbar extension torque (P less than or equal to 0.05) at all angles measured when compared with C. The greatest gains in torque were noted for groups A and B in their respective ranges of training but A and B did not differ from AB (P greater than 0.05) at any angle. These data indicate that limited ROM lumbar extension training through a 36 degrees ROM is effective for developing strength through 72 degrees of lumbar extension.