Robert S. Burnham

Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans

Abstract The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (V˙O2max) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle.

An Alternate Method of Radiofrequency Neurotomy of the Sacroiliac Joint: A Pilot Study of the Effect on Pain, Function, and Satisfaction

Background and Objectives: The sacroiliac joint (SIJ) can be a source of chronic refractory mechanical spine pain. Few previous studies have described radiofrequency (RF) sensory denervation of the SIJ; results have been inconsistent and technically demanding. This uncontrolled, prospective, cohort study evaluates the effects of an innovative method of RF ablation of the posterior sensory nerves of the SIJ on pain, analgesic use, disability, and satisfaction of patients suffering with chronic mechanical SIJ pain. Methods: Nine subjects with SIJ pain, confirmed by a local anesthetic joint block, were studied. Subjects were treated with a series of RF strip lesions performed adjacent to the lateral dorsal foraminal aperture plus conventional monopolar lesioning at the L5 dorsal ramus. Each subject completed a questionnaire twice before and at 1, 3, 6, 9, and 12 months after the procedure. The questionnaire evaluated pain intensity and frequency, analgesic intake, disability, satisfaction (with current pain level and the RF procedure), and procedure complications. Data were analyzed by using linear mixed model analysis. Results: After the procedure, significant reductions of back and leg pain frequency and severity, analgesic intake, and dissatisfaction with their current level of pain occurred. Complications were minimal. Overall, 8 of 9 subjects were satisfied with the procedure. Conclusions: RF sensory ablation of the SIJ using bipolar strip lesions is a technically uncomplicated and low-risk procedure. The resulting effects on pain, disability, and satisfaction are promising. Further evaluation of this technique, including randomized controlled trials, is recommended.

Histochemical changes in muscle of individuals with spinal cord injury following functional electrical stimulated exercise training.

Study Design: Longitudinal training. Objectives: To determine the effects of functional electrical stimulated (FES) leg cycle ergometer training on muscle histochemical characteristics in individuals with motor-complete spinal cord injury (SCI). Setting: University of Alberta, Edmonton, Alberta, Canada. Methods: Six individuals with motor-complete SCI (age 31–50 years; 3–25 years post-injury) trained using FES leg cycle ergometry for 30 min, 3 days per week for 8 weeks. Biopsies of the vastus lateralis muscle were obtained pre- and post-training and analyzed for fibre composition, fibre size and capillarization. Results: The majority of muscle fibres were classified as type 2 pre- and post-training. Average fibre area increased 23% (P<0.05) and capillary number increased 39% (P<0.05) with training. As a result of these proportional increases, capillarization expressed relative to fibre area was unchanged with training. Conclusions: FES leg cycle ergometer training results in proportional increases in fibre area and capillary number in individuals with SCI. Sponsorship: Supported by the Glenrose Rehabilitation Hospital.

Functional electrical stimulation exercise increases GLUT-1 and GLUT-4 in paralyzed skeletal muscle

The study purpose was to determine the effect of functional electrical stimulation (FES)-leg cycle ergometer training (30 minutes on 3 d/wk for 8 weeks) on the GLUT-1 and GLUT-4 content of paralyzed skeletal muscle. Biopsy samples of vastus lateralis muscle were obtained pre- and post-training from five individuals with motor-complete spinal cord injury ([SCI] four men and one woman aged 31 to 50 years, 3 to 25 years postinjury involving C5-T8). Western blot analysis indicated that GLUT-1 increased by 52% and GLUT-4 increased by 72% with training (P < .05). This coincided with an increase in the muscle oxidative capacity as indicated by a 56% increase in citrate synthase (CS) activity (P < .05) and an improvement in the insulin sensitivity index as determined from oral glucose tolerance tests (P < .05). It is concluded that FES endurance training is effective to increase glucose transporter protein levels in paralyzed skeletal muscle of individuals with SCI.

The Effectiveness of Topical Diclofenac for Lateral Epicondylitis

IntroductionGastrointestinal upset and local pain commonly limit the use of oral nonsteroidal anti-inflammatory drugs and corticosteroid injection as treatments for lateral epicondylitis. Transdermal administration of an anti-inflammatory drug could avoid these adverse effects. PurposeTo determine the effectiveness of topical diclofenac as a treatment of lateral epicondylitis. MethodsA convenience sample of 14 subjects meeting clinical criteria of chronic lateral epicondylitis participated in this randomized, double blind, crossover study. Each subject applied a plutonic lecithin liposomal organo-gel (PLO) over the affected lateral elbow three times daily for 1 week, followed by a 1-week “washout” period of no gel. A second topical PLO gel was then applied similarly for 1 week. Both gels were identical, but only one gel contained 2% diclofenac. Treatment order was randomized, and both the subject and tester were blinded. Pain and isometric wrist extension strength were measured using a visual analog pain scale (VAS) and a mounted manual muscle testing dynamometer, respectively, at the following time periods: just before application of the first gel, the last day of using the first gel, the last day of the washout week, and the last day of using the second gel. Analysis was performed using repeated measures analysis of variance. ResultsWhen subjects used diclofenac PLO, pain was significantly less than that during the pretreatment, washout, and placebo PLO periods (mean VAS; diclofenac PLO, 2.1; pretreatment, 3.5; washout, 3.4; placebo PLO, 3.6). Average wrist extension strength was significantly greater when subjects used diclofenac PLO (8.4 kg) than it was before treatment (5.9 kg). One subject developed a local rash while using diclofenac PLO. ConclusionTopical 2% diclofenac in PLO appears to provide effective short-term reduction in elbow pain and wrist extensor weakness associated with chronic lateral epicondylitis.

The effect of polytrauma in persons with traumatic spine injury. A prospective database of spine fractures.

Study Design. A mixed cross-sectional survey and cohort study using a prospectively gathered database of persons with traumatic spine injury. Objectives. To identify demographic and injury mechanism factors that predict greater injury severity, and to determine the effect of injury severity on outcomes in traumatic spine fracture. Summary of Background Data. Traumatic spine fracture outcome studies have focused on defining type and level of vertebral fracture without considering the severity of associated injuries. In the trauma population, greater injury severity has been shown to be related to worse outcome. No studies have been reported on the effect of injury severity on outcome in the traumatic spine fracture population. Methods. Prospectively collected data on 830 persons with traumatic spine injury who were admitted to a trauma hospital were reviewed. Patient demographics; injury mechanism; hospital events; and disability, employment, and pain status at discharge, 1 year, and 2 years after injury were recorded. Associations between these factors and trauma severity (Injury Severity Score) were explored using Pearson’s correlation and analysis of variance. Results. Trauma was more severe in patients who had been married previously, who were involved in a motor vehicle accident, were ejected from the vehicle, had loss of consciousness, had higher-level and multiple complicated vertebral fractures, or had neurologic deficit. Those more severely injured had longer lengths of stay, more surgery, more complications, higher mortality, more disability, and less return to work. Conclusions. Persons with traumatic spine injury and polytrauma have poorer short- and long-term outcomes. This high-risk group may require aggressive interventions, more hospital resources, and close follow-up observation after discharge from hospital to optimize outcome.

Evidence of autonomic dysreflexia during functional electrical stimulation in individuals with spinal cord injuries

The purpose of the investigation was to examine the safety and efficacy of functional electrical stimulation (FES)-assisted hydraulic resistance training in improving cardiovascular fitness in persons with spinal cord injuries. The cardiopulmonary responses of 10 high spinal cord injured (SCI) and five able bodied (AB) subjects were assessed during three bouts of FES-assisted leg extension exercise. The protocol involved three 30-minute tests: (1) unloaded leg extension, (2) hydraulically-resisted leg extension (loaded), and (3) a reproduction of the unloaded and loaded protocols to measure cardiac output (Q). Pre-measurements were made of body mass, mean limb weight, maximal force output and maximal oxygen uptake (incremental arm ergometry). Oxygen uptake (VO2), minute ventilation (Ve), respiratory exchange ratio (RER), heart rate (HR), blood pressure (BP) were recorded before, during and after tests. There was a significant difference in VO2 max between SCI and AB subjects. Cardiac output significantly increased between the loaded and unloaded tests. The significant increases from rest to unloaded and loaded exercise pointed to the potential value of adding resistance to a leg extension training regime. Heart rate and BP of the participants with SCI consistently demonstrated a response suggestive of autonomic dysreflexia. Upon stimulation an immediate increase in (predominantly systolic) BP was observed, followed by a fall in HR. On cessation of stimulation HR exhibited a substantial rebound effect and BP returned to normal levels. This response was highly reproducible and suggests caution be exercised in the use of FES for people with SCI with lesion levels above the major splanchnic outflow (T6).

Testosterone, cortisol and catecholamine responses to exercise stress and autonomic dysreflexia in elite quadriplegic athletes

Episodes of short high intensity exercise are associated with an increase in circulating total testosterone (T) in men. Mechanisms may include hemoconcentration, decreased metabolic clearance and/or increased synthesis. Beta-blockade abolishes the T response suggesting a direct beta-adrenergic effect on the testes. Some spinal cord injured (SCI) athletes deliberately induce autonomic dysreflexia (boosting) to enhance performance. Associated with this practice are elevated catecholamine (CA) levels and exaggerated responses to serum catecholamine levels. Since basal T levels are reported to be normal in the SCI male, the T response to acute high intensity exercise might be expected to be exaggerated by boosting and associated elevated CA levels. The acute exercise T response has not been examined in SCI men to date. To determine whether the increased CA values associated with boosting enhanced the exercise-induced T elevation we measured circulating levels of T, Cortisol (C), norepinephrine (NE) and epinephrine (E) before and after maximal exertion and a simulated 7.5 km race with and without boosting in eight elite quadriplegic athletes. Maximal incremental exercise and a simulated 7.5 km race resulted in a rise in T similar to able bodied men under normal exercise conditions. Under boosted conditions the rise in T was eliminated while NE levels were significantly elevated above unboosted levels. The data may suggest an inhibitory role for CA on T production or release under conditions of extreme stress. Other possible mechanisms include C induced suppression, impaired gonadotropin stimulation of the Leydig cell and CA mediated alterations in gonadal blood supply.

Assessment of isokinetic and hand-held dynamometer measures of shoulder rotator strength among individuals with spinal cord injury

OBJECTIVE To determine the intrarater reliability of the hand-held dynamometer (HHD) for the measurement of shoulder rotation and to examine the relationship between the peak force values of the HHD and the isokinetic dynamometer. PARTICIPANTS Twenty-five spinal cord injured individuals, 12 persons with paraplegia and 13 persons with tetraplegia between the ages of 18 and 42 years, were recruited from the community. SETTING Private practice clinic. PROCEDURES All participants were tested with the HHD by one examiner to determine reliability. On the same day, these participants underwent isokinetic testing to determine the relationship of the HHD and Cybex dynamometer measurements. RESULTS The intraclass correlation coefficients for the intrarater reliability ranged from .89 to .96. The Pearson product moment correlation was used to analyze the relationship between the two devices. All coefficients (.52 to .88) were statistically significant (p < .01); however, separate analyses for the persons with paraplegia and tetraplegia differed considerably. There was substantial variability of the isokinetic strength values at the lower levels of isometric strength. CONCLUSIONS The HHD can be used reliably to measure shoulder rotation in paraplegic and tetraplegic spinal cord injured individuals. Although it appears that the relationship between HHD and isokinetic measurement is poor for the participants with tetraplegia, the variability of the isokinetic scores indicates that this observation may be a function of the method of isokinetic measurements. Further study with a modified isokinetic testing protocol is needed to clarify the results of the participants with tetraplegia.

Functional electrical stimulation effect on orthostatic hypotension after spinal cord injury.

OBJECTIVE To investigate the possibility of using functional electrical stimulation (FES) to control orthostatic hypotension in patients with spinal cord injury (SCI) and to clarify the mechanism of the response. DESIGN Subjects were tilted by 10 degree increments with varying intensities of lower-extremity FES. Stimulation over muscles was compared to stimulation over noncontractile sites. SETTING Physical therapy department of a major rehabilitation center. PATIENTS Six patients with SCI above T6 (3 with recent injury recruited consecutively from an inpatient spinal cord rehabilitation unit, and 3 from the community with longstanding injury, recruited as volunteers). MAIN OUTCOME MEASURES Blood pressure, heart rate, and perceived presyncope score recorded at each tilt angle and analyzed using a multivariate analysis of variance statistical methodology. RESULTS Systolic and diastolic blood pressure increased with increasing stimulation intensities (systolic, p = .001; diastolic, p = .0019) and decreased with increasing angle of tilt (p < .001) regardless of the site of stimulation. Subjects tolerated higher angles of incline with electrical stimulation than without (p = .03). CONCLUSIONS FES causes a dose-dependent increase in blood pressure independent of stimulation site that may be useful in treating orthostatic hypotension.