Neena K. Sharma

The Effect of Exercise on Neuropathic Symptoms, Nerve Function, and Cutaneous Innervation in People with Diabetic Peripheral Neuropathy

UNLABELLED Although exercise can significantly reduce the prevalence and severity of diabetic complications, no studies have evaluated the impact of exercise on nerve function in people with diagnosed diabetic peripheral neuropathy (DPN). The purpose of this pilot study was to examine feasibility and effectiveness of a supervised, moderately intense aerobic and resistance exercise program in people with DPN. We hypothesized that the exercise intervention can improve neuropathic symptoms, nerve function, and cutaneous innervation. METHODS A pre-test post-test design was used to assess change in outcome measures following participation in a 10-week aerobic and strengthening exercise program. Seventeen subjects with diagnosed DPN (8 males/9 females; age 58.4±5.98; duration of diabetes 12.4±12.2 years) completed the study. Outcome measures included pain measures (visual analog scale), Michigan Neuropathy Screening Instrument (MNSI) questionnaire of neuropathic symptoms, nerve function measures, and intraepidermal nerve fiber (IENF) density and branching in distal and proximal lower extremity skin biopsies. RESULTS Significant reductions in pain (-18.1±35.5 mm on a 100 mm scale, P=.05), neuropathic symptoms (-1.24±1.8 on MNSI, P=.01), and increased intraepidermal nerve fiber branching (+0.11±0.15 branch nodes/fiber, P=.008) from a proximal skin biopsy were noted following the intervention. CONCLUSIONS This is the first study to describe improvements in neuropathic and cutaneous nerve fiber branching following supervised exercise in people with diabetic peripheral neuropathy. These findings are particularly promising given the short duration of the intervention, but need to be validated by comparison with a control group in future studies.

Aerobic Exercise Alters Analgesia and Neurotrophin-3 Synthesis in an Animal Model of Chronic Widespread Pain

Background Present literature and clinical practice provide strong support for the use of aerobic exercise in reducing pain and improving function for individuals with chronic musculoskeletal pain syndromes. However, the molecular basis for the positive actions of exercise remains poorly understood. Recent studies suggest that neurotrophin-3 (NT-3) may act in an analgesic fashion in various pain states. Objective The purpose of the present study was to examine the effects of moderate-intensity aerobic exercise on pain-like behavior and NT-3 in an animal model of widespread pain. Design This was a repeated-measures, observational cross-sectional study. Methods Forty female mice were injected with either normal (pH 7.2; n=20) or acidic (pH 4.0; n=20) saline in the gastrocnemius muscle to induce widespread hyperalgesia and exercised for 3 weeks. Cutaneous (von Frey monofilament) and muscular (forceps compression) mechanical sensitivity were assessed. Neurotrophin-3 was quantified in 2 hind-limb skeletal muscles for both messenger RNA (mRNA) and protein levels after exercise training. Data were analyzed with 2-factor analysis of variance for repeated measures (group × time). Results Moderate-intensity aerobic exercise reduced cutaneous and deep tissue hyperalgesia induced by acidic saline and stimulated NT-3 synthesis in skeletal muscle. The increase in NT-3 was more pronounced at the protein level compared with mRNA expression. In addition, the increase in NT-3 protein was significant in the gastrocnemius muscle but not in the soleus muscle, suggesting that exercise can preferentially target NT-3 synthesis in specific muscle types. Limitations Results are limited to animal models and cannot be generalized to chronic pain syndromes in humans. Conclusions This is the first study demonstrating the effect of exercise on deep tissue mechanical hyperalgesia in a rodent model of pain and providing a possible molecular basis for exercise training in reducing muscular pain.

Acidic Saline-Induced Primary and Secondary Mechanical Hyperalgesia in Mice

UNLABELLED Most of our knowledge about chronic musculoskeletal pain is based on cutaneous pain models. To test the hypothesis that animals develop chronic muscular hyperalgesia following intramuscular acidic saline injections, primary hyperalgesia within the gastrocnemius muscle was analyzed compared to secondary cutaneous hyperalgesia in the hind paw that develops following intramuscular acid saline injection. Two acidic saline (pH 4) injections were administrated into the gastrocnemius of female CF-1 mice. The results indicate that mice developed a robust hypersensitivity bilaterally in primary (gastrocnemius muscle) secondary (cutaneous hind paw) sites that lasted up to 2 weeks. In addition, primary hyperalgesia correlated well with levels of Fos expression. Fos expression patterns in the spinal cord were different for primary secondary site stimulation. Hind-paw palpation stimulated ipsilateral Fos expression in the superficial spinal laminae at L4/L5 levels, bilaterally in deep laminae at L2-L5 spinal levels. In contrast, gastrocnemius compression stimulated widespread Fos expression in all regions of the ipsilateral dorsal horn within L2-L6 spinal segments. These findings indicate that acidic saline injection induces primary hyperalgesia in muscle that the patterns of Fos expression in response to primary vs secondary stimulation are strikingly different. PERSPECTIVE This study assesses primary site muscular pain, which is the main complaint of people with musculoskeletal conditions, and identifies spinal patterns activated by noxious mechanical stimuli to the gastrocnemius. This study demonstrates approaches to test nociception arising from muscle aids in our understanding of spinal processing of primary secondary site hyperalgesia.

A randomized controlled pilot study of the therapeutic effects of yoga in people with Parkinson's disease

Background: Exercise can be beneficial for cardiopulmonary, musculoskeletal or neurological systems, and other factors including mood, and may be beneficial in reducing fall risks, dementia and variables associated with quality of life (QOL). Parkinsons disease (PD) produces progressive motor and cognitive deterioration that may leave those inflicted unable to participate in standard exercise programs. Alternative forms of exercise such as yoga may be successful in improving physical function, QOL and physiological variables for overall well-being. Aim: This randomized controlled pilot study investigated the effectiveness of yoga intervention on physiological and health-related QOL measures in people with PD. Methods and Materials: Thirteen people with stage 1-2 PD were randomized to either a yoga (n = 8) or a control group (n = 5). The yoga group participated in twice-weekly yoga sessions for 12 weeks. Participants were tested at baseline, and at 6 and 12 weeks using the Unified Parkinsons Disease Rating Scale (UPDRS), clinical measures of health-related QOL and physiological measures. Results: Significant improvement in UPDRS scores (P = .006), diastolic blood pressure (P = 0.036) and average forced vital capacity (P = 0.03) was noted in the yoga group over time. Changes between groups were also noted in two SF-36 subscales. Positive trends of improvement were noted in depression scores (P = 0.056), body weight (P = 0.056) and forced expiratory volume (P = 0.059). Yoga participants reported more positive symptom changes including immediate tremor reduction. Conclusions: The results suggest that yoga may improve aspects of QOL and physiological functions in stages 1-2 PD. Future larger studies are needed to confirm and extend our findings of the effects of yoga in PD.

Effect of Yoga on Motor Function in People with Parkinson's Disease: A Randomized, Controlled Pilot Study

Yoga is a form of exercise that may be beneficial to those with Parkinson’s disease (PD). There have been no randomized control research studies investigating the effect of yoga on those with PD. The objective was to determine if yoga can improve motor function in people with PD using a randomized controlled small group design. The PD participants were randomized into a yoga intervention group or a control group of no intervention. Assessment of physical function included motor examination scores from the Unified Parkinson’s Disease Rating Scale, posture, measures of extremity ROM, flexibility and strength, and biomechanical measures of balance and gait that occurred at 3 time points: prior to starting the intervention, at 6 weeks of intervention, and immediately following 12 weeks of intervention. Thirteen adults with PD met the inclusion and exclusion criteria. All participants were unfamiliar with yoga. An Iyengar Hatha yoga program was tailored to fit participants with PD and designed to improve strength, flexibility, body alignment, and overall well-being. A 60-minute session, including physical postures, breathing, and meditation was implemented twice a week for 12 weeks. A significant improvement was found in motor UPDRS scores (p=0.004) and Berg Balance Scale scores (p=0.04) in the yoga group. A general trend of positive outcomes in the yoga group for strength, ROM and flexibility were noted with significant differences at p=0.05 in selected hip and ankle measurements. Qualitative improvements in posture were observed and there were significant improvements in the onset time of foot unloading and onset time of foot lift off. Findings suggest that yoga practice improves motor function which may be partially explained by improvements in balance, strength, posture and gait. Due to the progressive nature of PD yoga programs may offer a way to maintain wellness and perhaps quality of life.

Pilot Study of Exercise Therapy on Painful Diabetic Peripheral Neuropathy

OBJECTIVE Painful diabetic peripheral neuropathy (DPN) is a common complication of diabetes. While the beneficial effect of exercise on diabetes is well established, its effect specifically on painful DPN has not been thoroughly explored. The objective of this pilot study was to examine the effect of aerobic exercise on pain in people with DPN. METHODS Fourteen sedentary individuals (mean age 57 ± 5.11 years) with painful DPN were enrolled in a 16-week, supervised aerobic exercise program. The Brief Pain Inventory-Diabetic Peripheral Neuropathy was used to assess pain intensity (worst, least, average, now) and pain interference with daily life (activity, mood, walk, normal work, relationship, sleep, enjoyment of life) pre intervention and postintervention. Body mass index (BMI), maximum oxygen uptake (VO2max ), hemoglobin A1c (HbA1c), and blood pressure were also measured preintervention and postintervention as secondary outcomes of interest. RESULTS Significant reductions in pain interference were observed with walking (4.93 ± 3.03 pre to 3.29 ± 2.89 post, P = 0.016), normal work (5.39 ± 3.32 pre to 3.79 ± 3.04 post, P = 0.032), relationship with others (3.96 ± 3.53 pre to 1.29 ± 1.27 post, P = 0.006), sleep (5.11 ± 3.04 pre to 3.5 ± 3.03 post, P = 0.02), and the overall pain interference (4.65 ± 2.70 pre to 2.97 ± 2.22 post, P = 0.013) following the intervention; however, there was no change in pain intensity. VO2max increased significantly postintervention (16.02 ± 3.84 ml/kg/min pre to 17.18 ± 4.19 ml/kg/min, P = 0.028), while BMI, HbA1c, and blood pressure remained unchanged. CONCLUSION These preliminary results suggest that perceived pain interference may be reduced following an aerobic exercise intervention among people with painful DPN, without a change in pain intensity. Further validation by a RCT is needed.

Static Progressive Stretch Brace as a Treatment of Pain and Functional Limitations Associated With Plantar Fasciitis A Pilot Study

Plantar fasciitis is a common and hard-to-treat disorder of the foot. Numerous studies have compared various stretching exercises, but the use of a day-wear static progressive stretch brace has not been studied. A randomized, single-blinded trial was conducted to compare the effectiveness of a static progressive stretch brace to standard care of active stretching exercises. Thirteen subjects (12 women and 1 man; mean age, 42 ± 9.0 years) with plantar fasciitis participated in this study between January 2004 and March 2007. Subjects were randomized to either an exercise group (static stretch group, n = 8) or a brace group (static progressive stretch group, n = 9) for an 8-week treatment period and 1-month follow up. Both groups received basic off-the-shelf foot orthoses. Data were available for 7 subjects in the exercise group and 6 in the brace group. Pain and functional limitations were evaluated with the Foot Functional Index pain subscale, the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, and great toe extension motion. Overall pain and morning pain improved in both groups as compared with baseline measures (repeated-measures analysis of variance, P = .04 and P = .02, respectively). Functional rating also improved in both groups (repeated-measures analysis of variance, P = .005). No changes were found in either group with great toe extension range of motion. In addition, there was no significant group difference or interaction with time and group with any measures. Both interventions (static, exercise, and brace stretching) were beneficial for treating pain and functional limitations, suggesting that static progressive stretch brace is an effective alternative option to static stretching exercises for people with plantar fasciitis.

Painful Diabetic Peripheral Neuropathy: Presentations, Mechanisms, and Exercise Therapy

Diabetic peripheral neuropathy (DPN) is a frequent complication of diabetes and a major cause of morbidity and increased mortality. It is typically characterized by significant deficits in tactile sensitivity, vibration sense, lower-limb proprioception, and kinesthesia. Painful diabetic neuropathy (P-DPN) is a common phenotype of DPN that affects up to one-third of the general diabetic population. P-DPN has been shown to be associated with significant reductions in overall quality of life, increased levels of anxiety and depression, sleep impairment, and greater gait variability. The purpose of this review is to examine proposed mechanisms of P-DPN, summarize current treatment regimen, and assess exercise as a potential therapy for P-PDN. Although exercise has been shown to be an effective therapeutic modality for diabetes, its specific effects on DPN and especially the painful phenotype have not been sufficiently investigated in current literature. Several rodent models and clinical trials have presented promising results in this area, and warrant further investigations examining the effect of exercise on P-DPN.

Novice lifters exhibit a more kyphotic lifting posture than experienced lifters in straight-leg lifting.

As torso flexion and repetitive lifting are known risk factors for low back pain and injury, it is important to investigate lifting techniques that might reduce injury during repetitive lifting. By normalizing lumbar posture to a subjects range of motion (ROM), as a function of torso flexion, this research examined when subjects approached their range of motion limits during dynamic lifting tasks. For this study, it was hypothesized that experienced lifters would maintain a more neutral lumbar angle relative to their range of motion, while novice lifters would approach the limits of their lumbar ROM during the extension phase of a straight-leg lift. The results show a statistically significant difference in lifting patterns for these two groups supporting this hypothesis. The novice group maintained a much more kyphotic lumbar angle for both the flexion (74% of the lumbar angle ROM) and extension phases (86% of the lumbar angle ROM) of the lifting cycle, while the experienced group retained a more neutral curvature throughout the entire lifting cycle (37% of lumbar angle ROM in flexion and 48% of lumbar angle ROM in extension). By approaching the limits of their range of motion, the novice lifters could be at greater risk of injury by placing greater loads on the supporting soft tissues of the spine. Future research should examine whether training subjects to assume more neutral postures during lifting could indeed lower injury risks.

Immediate Effect of Lumbar Mobilization on Activity of Erector Spinae and Lumbar Multifidus Muscles

Objective: The purpose of this study was to investigate the effect of grade IV lumbar mobilization on the activity/contraction of erector spinae (ES) and lumbar multifidus (LM) muscles in healthy people. Methods: A randomized, repeated‐measures design was used. Sixteen healthy subjects attended 3 testing sessions with a different intervention in each session (no intervention, grade IV central lumbar mobilization at L4, and placebo/light touch). Lying in a prone position, subjects lifted a light weight with their right arm while ultrasound images of LM and surface electromyography signals of ES were captured before and immediately after application of the intervention in the session. The contraction of LM was calculated from US images, and the root mean square was calculated from the electromyography signals of ES and used as outcome measures. Results: A significant difference was found in LM contraction between the placebo and mobilization intervention (difference = 0.04, P = .02). There was no difference for the root mean square of electromyography signals between the interventions. Conclusion: The significant difference in LM contraction was small and may not have clinical significance. Lumbar mobilization did not change the activity of ES in healthy people. Future studies with larger samples are needed to confirm our findings and to investigate the effect of mobilization on back muscles in people with low back pain.