Short-Term Effect of Spinal Manipulation on Pain Perception,Spinal Mobility,and Full Height Recovery in Male Subjects With Degenerative Disk Disease: A Randomized Controlled Trial

Objective

To evaluate the short-term effect on spinal mobility, pain perception, neural mechanosensitivity, and full height recovery after high-velocity, low-amplitude (HVLA) spinal manipulation (SM) in the lumbosacral joint (L5-S1).

Design

Randomized, double-blind, controlled clinical trial with evaluations at baseline and after intervention.

Setting

University-based physical therapy research clinic.

Participants

Men (N=40; mean age ± SD, 38±9.14y) with diagnosed degenerative lumbar disease at L5-S1 were randomly divided into 2 groups: a treatment group (TG) (n=20; mean age ± SD, 39±9.12y) and a control group (CG) (n=20; mean age ± SD, 37±9.31y). All participants completed the intervention and follow-up evaluations.

Interventions

A single L5-S1 SM technique (pull-move) was performed in the TG, whereas the CG received a single placebo intervention.

Main Outcome Measures

Measures included assessing the subject's height using a stadiometer. The secondary outcome measures included perceived low back pain, evaluated using a visual analog scale; neural mechanosensitivity, as assessed using the passive straight-leg raise (SLR) test; and amount of spinal mobility in flexion, as measured using the finger-to-floor distance (FFD) test.

Results

The intragroup comparison indicated a significant improvement in all variables in the TG (P<.001). There were no changes in the CG, except for the FFD test (P=.008). In the between-group comparison of the mean differences from pre- to postintervention, there was statistical significance for all cases (P<.001).

Conclusions

An HVLA SM in the lumbosacral joint performed on men with degenerative disk disease immediately improves self-perceived pain, spinal mobility in flexion, hip flexion during the passive SLR test, and subjects' full height. Future studies should include women and should evaluate the long-term results.     

Intra-abdominal pressure and abdominal wall muscular function: Spinal unloading mechanism

Background

The roles of antagonistic activation of abdominal muscles and of intra-abdominal pressurization remain enigmatic, but are thought to be associated with both spinal unloading and spinal stabilization in activities such as lifting. Biomechanical analyses are needed to understand the function of intra-abdominal pressurization because of the anatomical and physiological complexity, but prior analyses have been over-simplified.

Methods

To test whether increased intra-abdominal pressure was associated with reduced spinal compression forces for efforts that generated moments about each of the principal axis directions, a previously published biomechanical model of the spine and its musculature was modified by the addition of anatomically realistic three-layers of curved abdominal musculature connected by fascia to the spine. Published values of muscle cross-sectional areas and the active and passive stiffness properties were assigned. The muscle activations were calculated assuming minimized muscle stress and stretch for the model loaded with flexion, extension, lateral bending and axial rotation moments of up to 60 Nm, along with intra-abdominal pressurization of 5 or 10 kPa (37.5 or 75 mm Hg) and partial bodyweight (340 N).

Findings

The analysis predicted a reduction in spinal compressive force with increase in intra-abdominal pressurization from 5 to 10 kPa. This reduction at 60 Nm external effort was 21% for extension effort, 18% for flexion effort, 29% for lateral bending and 31% for axial rotation.

Interpretation

This analysis predicts that intra-abdominal pressure produces spinal unloading, and shows likely muscle activation patterns that achieve this.     

Creation of an asymmetrical gradient of back muscle activity and spinal stiffness during asymmetrical hip extension

Background

Low back pain is often associated with increased spinal stiffness which thought to arise from increased muscle activity. Unfortunately, the association between paraspinal muscle activity and paraspinal stiffness, as well as the spatial distribution of this relation, is unknown. The purpose of this investigation was to employ new technological developments to determine the relation between spinal muscle contraction and spinal stiffness over a large region of the lumbar spine.

Methods

Thirty-two male subjects performed graded isometric prone right hip extension at four different exertion levels (0%, 10%, 25% and 50% of the maximum voluntary contraction) to induce asymmetric back muscle activity. The corresponding stiffness and muscle activity over bilateral paraspinal lumbar regions was measured by indentation loading and topography surface electromyography, respectively. Paraspinal stiffness and muscle activity were then plotted and their correlation was determined.

Findings

Data from this study demonstrated the existence of an asymmetrical gradient in muscle activation and paraspinal stiffness in the lumbar spine during isometric prone right hip extension. The magnitude and scale of the gradient increased with the contraction force. A positive correlation between paraspinal stiffness and paraspinal muscle activity existed irrespective of the hip extension effort (Pearson correlation coefficient, range 0.566–0.782 (P < 0.001)).

Interpretation

Our results demonstrate the creation of an asymmetrical gradient of muscle activity and paraspinal stiffness during right hip extension. Future studies will determine if alterations in this gradient may possess diagnostic or prognostic value for patients with low back pain.     

Intervertebral neural foramina deformation due to two types of repetitive combined loading

Background

Tissue compression and noxious stimuli are known to elicit pain from neural tissues in the spine. Compression of nerve roots due to decreases in the intervertebral foramina may be caused by posture, sustained loading and disc height loss, herniation, or altered mechanics. It has been established that non-neutral postures combined with repeated loading can cause disc herniations, however information regarding the effect of repetitive axial twist loading is limited. The objectives of this study were twofold; to measure the occlusion of the foramina due to two types of repetitive loading and to investigate whether repetitive combined axial twist loading can contribute to disc injury.

Methods

Sixteen porcine cervical spine segments (C5/6) were subjected to 1500 N of compression combined with either repetitive flexion–extension motions or 16.4° (Standard Deviation 2.1) of static flexion with repetitive axial twist motions. The foramina pressure was measured bilaterally using plastic tubing and a custom pressure monitoring system. Specimens were loaded until 10,000 cycles were reached or disc herniation occurred.

Findings

Significantly larger pressure (pre–post difference) developed in the intervertebral foramina of specimens that were repetitively flexed–extended (P = 0.028) compared to those that were repetitively twisted. All of the flexed–extended specimens herniated, whereas in the twisted specimens five (62.5%) had incomplete herniations, one (12.5%) sustained a facet fracture, and two (25%) had no damage. There was no difference between the loading groups for vertical height loss (P = 0.994).

Interpretation

Repetitive loading of flexion–extension motions are a viable pain generating pathway in absence of distinguishing height loss. This information may be useful to consider for the diagnosis and treatment of nerve root compression.     

Accurate prediction of the needle depth required for successful lumbar puncture

Introduction

The aim of this study is to formulate an accurate estimate of the spinal needle depth for a successful lumbar puncture in pediatric patients.

Methods

This is a prospective study of pediatric oncology patients who had lumbar punctures in the course of their treatment. The distance from skin entry point to the tip of the spinal needle was measured after lumbar punctures were performed. The relationship between the depth of needle insertion with weight, height, body surface area, body mass index, intervertebral space used, ethnicity, and sex of patient were studied. Predictive statistical models were used for the formulation of the ideal lumbar puncture needle depth.

Results

Two hundred seventy-nine patients who had nontraumatic lumbar punctures were studied. The patient characteristics were as follows: age, 0.5 to 15 years; weight, 7 to 63 kg; and height, 70 to 162 cm. Analysis using multiple regression tests with stepwise approach showed a strong relationship between the lumbar puncture needle depth and weight/height ratio. By using a predictive regression model, ideal depth of needle insertion (cm) = 10 [weight(kg)/height(cm)] + 1, with a regression coefficient r = 0.77.

Conclusion

This formula is accurate and practical with less complex calculations. However, further validation in a prospective study will be needed.     

Effect of Spinal Manipulation Thrust Duration on Trunk Mechanical Activation Thresholds of Nociceptive-Specific Lateral Thalamic Neurons

Objective

The objective of this preliminary study was to determine if high-velocity, low-amplitude spinal manipulation (HVLA-SM) thrust duration alters mechanical trunk activation thresholds of nociceptive-specific (NS) lateral thalamic neurons.

Methods

Extracellular recordings were obtained from 18 NS neurons located in 2 lateral thalamic nuclei (ventrolateral [n = 12] and posterior [n = 6]) in normal anesthetized Wistar rats. Response thresholds to electronic von Frey anesthesiometer (rigid tip) mechanical trunk stimuli applied in 3 lumbar directions (dorsal-ventral, 45° caudal, and 45° cranial) were determined before and immediately after the delivery of 3 HVLA-SM thrust durations (time control 0, 100, and 400 milliseconds). Mean changes in mechanical trunk activation thresholds were compared using a mixed model analysis of variance.

Results

High-velocity, low-amplitude spinal manipulation duration did not significantly alter NS lateral thalamic neurons' mechanical trunk responses to any of the 3 directions tested with the anesthesiometer.

Conclusions

This study is the first to examine the effect of HVLA-SM thrust duration on NS lateral thalamic mechanical response thresholds. High-velocity, low-amplitude spinal manipulation thrust duration did not affect mechanical trunk thresholds.     

Effects of Cervical Spine Manual Therapy on Range of Motion,Head Repositioning,and Balance in Participants With Cervicogenic Dizziness: A Randomized Controlled Trial

Objective

To evaluate and compare the effects of 2 manual therapy interventions on cervical spine range of motion (ROM), head repositioning accuracy, and balance in patients with chronic cervicogenic dizziness.

Design

Randomized controlled trial with 12-week follow-up using blinded outcome assessment.

Setting

University School of Health Sciences.

Participants

Participants (N=86; mean age ± SD, 62.0±12.7y; 50% women) with chronic cervicogenic dizziness.

Interventions

Participants were randomly assigned to 1 of 3 groups: sustained natural apophyseal glides (SNAGs) with self-SNAG exercises, passive joint mobilization (PJM) with ROM exercises, or a placebo. Participants each received 2 to 6 treatments over 6 weeks.

Main Outcome Measures

Cervical ROM, head repositioning accuracy, and balance.

Results

SNAG therapy resulted in improved (P≤.05) cervical spine ROM in all 6 physiological cervical spine movement directions immediately posttreatment and at 12 weeks. Treatment with PJM resulted in improvement in 1 of the 6 cervical movement directions posttreatment and 1 movement direction at 12 weeks. There was a greater improvement (P<.01) after SNAGs than PJM in extension (mean difference, −7.5°; 95% confidence interval [CI], −13° to −2.0°) and right rotation (mean difference, −6.8°; 95% CI, −11.5° to −2.1°) posttreatment. Manual therapy had no effect on balance or head repositioning accuracy.

Conclusions

SNAG treatment improved cervical ROM, and the effects were maintained for 12 weeks after treatment. PJM had very limited impact on cervical ROM. There was no conclusive effect of SNAGs or PJMs on joint repositioning accuracy or balance in people with cervicogenic dizziness.     

Intertester Agreement and Validity of Identifying Lumbar Pain Provocative Movement Patterns Using Active and Passive Accessory Movement Tests

Objective

The purpose of this study was to evaluate the interexaminer agreement and validity of active and passive pain provocation tests in the lumbar spine.

Methods

Two blinded raters examined 36 participants, 18 of whom were asymptomatic and 18 reported subacute nonspecific low back pain (LBP). Two types of pain provocation tests were performed: (1) physiological movements in single (flexion/extension) and, when necessary, combined planes and (2) passive accessory intervertebral movement tests of each lumbar vertebra in prone with the lumbar spine in neutral, flexion, and extension position.

Results

The interobserver agreement in both groups was good to excellent for the identification of flexion (κ = 0.87-1) or extension (κ = 0.65-0.74) as the most painful pattern of spinal movement. In healthy participants, 0% was identified as having a flexion provocative pattern and 8.8% were identified as having an extension provocative pattern. In the LBP group, 20% were identified as having a flexion provocative pattern vs 60% with an extension provocative pattern. The average interexaminer agreement for passive accessory intervertebral movement tests in both groups was moderate to excellent (κ = 0.42-0.83). The examiners showed good sensitivity (0.67-0.87) and specificity (0.82-0.85) to distinguish participants with LBP using this combined examination procedure.

Conclusion

The use of a combination of pain provocative tests was found to have acceptable interexaminer reliability and good validity in identifying the main pain provocative movement pattern and the lumbar segmental level of involvement. These pain provocation tests were able to distinguish participants with LBP from asymptomatic participants and may help clinicians in directing manual therapy treatment.     

Effects of Stimulating Hip and Trunk Muscles on Seated Stability,Posture, and Reach After Spinal Cord Injury

Objective

To determine the stimulated strength of the paralyzed gluteal and paraspinal muscles and their effects on the seated function of individuals with paralysis.

Design

Case series with subjects acting as their own concurrent controls.

Setting

Hospital-based clinical biomechanics laboratory.

Participants

Users (N=8) of implanted neuroprostheses for lower extremity function with low-cervical or thoracic level injuries.

Interventions

Dynamometry and digital motion capture both with and without stimulation to the hip and trunk muscles.

Main Outcome Measures

Isometric trunk extension moment at 0°, 15°, and 30° of flexion; seated stability in terms of simulated isokinetic rowing; pelvic tilt, shoulder height, loaded and unloaded bimanual reaching to different heights, and subjective ratings of difficulty during unsupported sitting.

Results

Stimulation produced significant increases in mean trunk extension moment (9.2±9.5Nm, P<.001) and rowing force (27.4±23.1N, P<.012) over baseline volitional values. Similarly, stimulation induced positive changes in average pelvic tilt (16.7±15.7°) and shoulder height (2.2±2.5cm) during quiet sitting and bimanual reaching, and increased mean reach distance (5.5±6.6cm) over all subjects, target heights, and loading conditions. Subjects consistently rated tasks with stimulation easier than voluntary effort alone.

Conclusions

In spite of considerable intersubject variability, stabilizing the paralyzed trunk with electrical stimulation can positively impact seated posture, extend forward reach, and allow exertion of larger forces on objects in the environment.     

Symptoms of Depression Over Time in Adults With Pediatric-Onset Spinal Cord Injury

Objective

To investigate the prevalence of depressive symptoms in adults with pediatric-onset spinal cord injury (SCI) and explore potential risk factors that may be associated with elevated symptoms.

Design

Longitudinal, cohort survey over a period of 2 to 9 years. Follow-up occurred approximately every year, a total of 868 interviews were conducted, and most participants contributed to at least 3 waves of data (72%; range, 2–8; mean, 4.34±2.16).

Setting

Community.

Participants

Adults (N=214; 133 men; mean age at first interview, 29.52±5.21y; range, 24–42y) who sustained an SCI prior to age 19 (mean age at injury, 13.93±4.37y; range, 0–18y). Participants tended to have complete injuries (71%) and tetraplegia (58%).

Interventions

Not applicable.

Main Outcome Measures

Participants completed measures assessing psychosocial functioning, physical independence, participation, and depression at each time point. Multilevel growth modeling analyses were used to explore depression symptoms across time.

Results

Depression symptoms at initial status were typically minimal (3.07±.24; 95% confidence interval, 2.6–3.54) but fluctuated significantly over time (P<.01). Several factors emerged as significant predictors of depressive symptoms in the final model, including less community participation (P<.01), incomplete injury (P=.02), hazardous drinking (P=.02), bladder incontinence (P=.01), and pain (P=.03). Within individuals, as bowel accidents (P<.01) and pain increased (P<.01), depression scores increased; however, marriage resulted in decreases in depression scores for individuals (P=.02).

Conclusions

These findings suggest that most patients with pediatric-onset SCI are psychologically resilient, but strategies to minimize secondary health complications and foster community participation and engagement should be considered.     

In vivo loads in the lumbar L3–4 disc during a weight lifting extension

Background

Knowledge of in vivo human lumbar loading is critical for understanding the lumbar function and for improving surgical treatments of lumbar pathology. Although numerous experimental measurements and computational simulations have been reported, non-invasive determination of in vivo spinal disc loads is still a challenge in biomedical engineering. The object of the study is to investigate the in vivo human lumbar disc loads using a subject-specific and kinematic driven finite element approach.

Methods

Three dimensional lumbar spine models of three living subjects were created using MR images. Finite element model of the L3–4 disc was built for each subject. The endplate kinematics of the L3–4 segment of each subject during a dynamic weight lifting extension was determined using a dual fluoroscopic imaging technique. The endplate kinematics was used as displacement boundary conditions to calculate the in-vivo disc forces and moments during the weight lifting activity.

Findings

During the weight lifting extension, the L3–4 disc experienced maximum shear load of about 230 N or 0.34 bodyweight at the flexion position and maximum compressive load of 1500 N or 2.28 bodyweight at the upright position. The disc experienced a primary flexion–extension moment during the motion which reached a maximum of 4.2 Nm at upright position with stretched arms holding the weight.

Interpretation

This study provided quantitative data on in vivo disc loading that could help understand intrinsic biomechanics of the spine and improve surgical treatment of pathological discs using fusion or arthroplasty techniques.     

Effectiveness of Supported Employment for Veterans With Spinal Cord Injury: 2-Year Results

Objective

To examine if supported employment (SE) remains more effective than treatment as usual (TAU) in returning veterans to competitive employment after spinal cord injury (SCI) at 2-year follow-up.

Design

Prospective, randomized, controlled, multisite trial of SE versus TAU with 24 months of follow-up.

Setting

SCI centers.

Participants

Subjects (N=201) were enrolled and completed baseline interviews. At interventional sites, subjects were randomized to SE (n=81) or TAU (n=76). At observational sites, 44 subjects were enrolled in a nonrandomized TAU condition.

Intervention

The intervention was a SE program called the SCI Vocational Integration Program, which followed the principles of the individual placement and support model of SE for persons with mental illness.

Main Outcome Measures

Competitive employment in the community within 2 years.

Results

For the entire 2-year follow-up period, SE subjects were significantly more likely to achieve employment (30.8%; 95% confidence interval [CI], 21.8–41.6) than either the TAU subjects at the intervention sites (10.5%; 95% CI, 5.2–19.7; P<.001) or the TAU subjects at the observational sites (2.3%; 95% CI, 0.0–12.9; P<.002). Most subjects who obtained competitive employment did so in year 1, and the average time to first employment was about 17 weeks.

Conclusions

SE was better than usual practices in improving employment outcomes for veterans with SCI across a 2-year follow-up period. Although SE continued to be superior to traditional practices over the entire study, the first year of participation in SE may represent a critical window for achieving employment after SCI.     

The effect of interspinous implant surgery on back surface shape and radiographic lumbar curvature

Background

Interspinous process implants, used to augment lumbar spine surgery, putatively induce a local segmental lumbar kyphosis yet few investigations outline the effect in vivo on thoracolumbar sagittal curvature. Changes in lumbar skeletal alignment and posture have traditionally relied upon radiographic and back surface spinal curvature measurements, respectively.

Methods

Lumbar lordosis curvature in 10 healthy subjects (6F, 4M; mean age 36 years) and 10 interspinous implant lumbar surgery patients (5F, 5M; mean age 51 years) was assessed with rasterstereography at baseline and at 6 weeks. Skeletal lumbar lordosis in standing was measured from lateral erect radiography pre- and 6 weeks post-operatively in the surgical cohort, and compared to angulation obtained for surface lordosis curvature derived from rasterstereography.

Findings

Repeatable measurement of standing lumbar lordosis from rasterstereographic back shape imaging in healthy volunteers and lumbar surgery cases was demonstrated. Reductions of 0.6 (NS) in healthy and 3.1 (significant, P < 0.001) in surgical subjects were recorded for surface lumbar lordosis angle between the 6 week time-points. Slight flattening of the segmental angle and regional lordosis after DIAM surgery was revealed by radiography. Skeletal and surface lumbar lordosis changes were uncorrelated preoperatively (ρ = 0.28) and postoperatively (ρ = 0.26).

Interpretation

Rasterstereography is sensitive in assessing lumbar lordosis changes in healthy and lumbar surgical individuals over time. Surgery with DIAM for lumbar pathology may result in an initial mild flattening of lordosis. Serial investigations of spinal curvature after surgery with DIAM interspinous implant are warranted in order to better understand the time-course of spinal posture changes of such cases.     

Relationship Between Sleep,Pain, and Disability in Patients With Spinal Pathology

Objective

To characterize sleep and its relationship with disability and pain in patients with spine pathology.

Design

A survey study.

Setting

A university-based hospital spine clinic.

Participants

Subjects (N=121) with mixed-etiology spine pathology.

Interventions

Not applicable.

Main Outcome Measures

Self-reported disability (Oswestry Disability Index [ODI]), back and leg pain intensity, the effect of back or leg pain on function, and sleep (Pittsburgh Sleep Quality Index [PSQI]) assessments were completed.

Results

Severe disability was evident with a mean ODI ± SD of 54.9±14, with mean pain intensities ± SD of 50±30mm and 54±27mm of 100mm for the leg and back, respectively. The mean PSQI ± SD was 10.4±5.3, with 87% of participants scoring greater than the sleep-disordered threshold of 5. PSQI was correlated to ODI (r=.53, P<.001), and ODI without the sleep component (r=.47, P<.001). Six of the subscales of PSQI were all also significantly correlated to ODI (.25<r<.42, P<.05). Stepwise regression (ODI dependent variables; PSQI, pain intensity and function, age, body mass index as independent variables) was performed. PSQI was retained in the model along with 2 pain measures (r²=.50, P<.001). Substitution of the 7 subscales for the overall PSQI score revealed 2 subscales (sleep quality, use of sleep medications) as predictors of ODI (r²=.490, P<.001).

Conclusions

Despite its being intuitive that sleep disorders will be present in patients with spinal disorders, it was surprising that sleep quality was an independent predictor of disability along with pain. Furthermore, sleep quality is more closely correlated to disability than leg pain, which is the current focus of medical interventions.     

Alterations in Cortical and Cerebellar Motor Processing in Subclinical Neck Pain Patients Following Spinal Manipulation

Objective

The purpose of this study was investigate whether there are alterations in cerebellar output in a subclinical neck pain (SCNP) group and whether spinal manipulation before motor sequence learning might restore the baseline functional relationship between the cerebellum and motor cortex.

Methods

Ten volunteers were tested with SCNP using transcranial magnetic stimulation before and after a combined intervention of spinal manipulation and motor sequence learning. In a separate experiment, we tested 10 healthy controls using the same measures before and after motor sequence learning. Our transcranial magnetic stimulation measurements included short-interval intracortical inhibition, long-interval intracortical inhibition, and cerebellar inhibition (CBI).

Results

The SCNP group showed a significant improvement in task performance as indicated by a 19% decrease in mean reaction time (P < .0001), which occurred concurrently with a decrease in CBI following the combined spinal manipulation and motor sequence learning intervention (F_1,6 = 7.92, P < .05). The control group also showed an improvement in task performance as indicated by a 25% increase in reaction time (P < .001) with no changes to CBI.

Conclusions

Subclinical neck pain patients have altered CBI when compared with healthy controls, and spinal manipulation before a motor sequence learning task changes the CBI pattern to one similar to healthy controls.     

Assisted Movement With Proprioceptive Stimulation Reduces Impairment and Restores Function in Incomplete Spinal Cord Injury

Objective

To test whether treatment with assisted movement with enhanced sensation (AMES) using vibration to the antagonist muscle would reduce impairments and restore upper limb function in people with incomplete tetraplegia.

Design

Prospective, pre-post study.

Setting

Laboratory and rehabilitation hospital.

Participants

We recruited 15 arms from 10 individuals (8 men; mean age, 40.5y; mean years postspinal cord injury [SCI], 3) with chronic, incomplete tetraplegia.

Intervention

Two or three 20-minute sessions per week over 9 to 13 weeks (25 sessions total) on the AMES device, which combines repeated movement with targeted vibration to the antagonist muscle.

Main Outcome Measures

Strength and active motion tests on the AMES device; International Standards for the Neurological Classification of SCI (ISNCSCI) motor and sensory examinations; Modified Ashworth Scale (MAS); grasp and release test (GRT); Van Lieshout Test (VLT); and Capabilities of Upper Extremity questionnaire (CUE).

Results

The AMES strength test scores improved significantly in metacarpophalangeal flexion (P=.024) and extension (P=.007) and wrist flexion (P=.001) and extension (P<.000). The AMES active motion scores improved in the hand (P=.001) and wrist (P=.001). The MAS and ISNCSCI scores remained unchanged, whereas the GRT scores increased (P=.025). Post hoc analysis showed a trend from pre- to posttreatment (P=.068) and a significant change from pretreatment to 3-month follow-up (P=.046). There was no significant change in the VLT (P=.951) or the CUE (P=.164). Five of the 10 participants reported a return of sensation to the digits after the first, second, or third treatment session.

Conclusions

People with chronic, incomplete tetraplegia may experience improvements in impairments and function after treatment on a device combining assisted movement and proprioceptive stimulation. Further investigation is warranted.     

Electrically Induced Resistance Training in Individuals With Motor Complete Spinal Cord Injury

Objective

To examine the effects of 16 weeks of electrically induced resistance training on insulin resistance and glucose tolerance, and changes in muscle size, composition, and metabolism in paralyzed muscle.

Design

Pre-post intervention.

Setting

University-based trial.

Participants

Participants (N=14; 11 men and 3 women) with chronic (>2y post spinal cord injury), motor complete spinal cord injury.

Intervention

Home-based electrically induced resistance exercise training twice weekly for 16 weeks.

Main Outcome Measures

Plasma glucose and insulin throughout a standard clinical oral glucose tolerance test, thigh muscle and fat mass via dual-energy x-ray absorptiometry, quadriceps and hamstrings muscle size and composition via magnetic resonance imaging, and muscle oxidative metabolism using phosphorus magnetic resonance spectroscopy.

Results

Muscle mass increased in all participants (mean ± SD, 39%±27%; range, 5%–84%). The mean change ± SD in intramuscular fat was 3%±22%. Phosphocreatine mean recovery time constants ± SD were 102±24 and 77±18 seconds before and after electrical stimulation-induced resistance training, respectively (P<.05). There was no improvement in fasting blood glucose levels, homeostatic model assessment calculated insulin resistance, 2-hour insulin, or 2-hour glucose.

Conclusions

Sixteen weeks of electrical stimulation-induced resistance training increased muscle mass, but did not reduce intramuscular fat. Similarly, factors associated with insulin resistance or glucose tolerance did not improve with training. We did find a 25% improvement in mitochondrial function, as measured by phosphocreatine recovery rates. Larger improvements in mitochondrial function may translate into improved glucose tolerance and insulin resistance.