Association of BMI with Neurodynamics in Healthy Adults: Review

Abstract

Neurodynamics is the science of relationships between mechanics and physiology of nervous system. It is the assessement and treatment of physical health of nervous system. Differentiating the body tissues involved in musculoskeletal pain disorders is a key component of the clinical evaluation. There is association between obesity and increased nerve size which suggests endoneurial oedema as a metabolic mechanism that causes intrafascicular swelling. To review the literature available on Association of BMI with neurodynamics. The reviewed literature was searched using different search engines and different keywords. The Source of the data has been electronic sources (Google Scholar, PubMed, and journals). All the articles were screened for title and inclusion-exclusion criteria. A total of 8 articles with a good level of evidence were included and tabulated revealing their important factors like a year, author, title, method and conclusion. The article published in the English language was included in the study. There is significant correlation of BMI with neurodynamic tests performed clinically for diagnostic as well as therapeutic purpose.

Introduction

I. INTRODUCTION

Neurodynamics is the science of relationships between mechanics and physiology of nervous system. It is the assessment and treatment of physical health of nervous system. Differentiating the body tissues involved in musculoskeletal pain disorders is a key component of the clinical evaluation. Neural tissue involvement can be evaluated through tests that assess its physiological and mechanical capabilities. Those tests, known as neurodynamic tests. Neurodynamic tests are considered to be able to detect increased nerve mechanosensitivity.3 Thus Physical therapists and other healthcare providers use neural tension tests (neurodynamic tests) as part of the clinical examination to help differentiate the underlying pathoanatomic structures. The most common neural tension tests include the straight leg raise test (SLR), the seated slump test (SST), and the upper limb neural tension test (ULNTT).5

Nerve conduction study (NCS) results are affected by factors such as gender, age, height, and weight1. There is potential for increased measurement error due to greater soft tissue excursion relative to underlying bony landmarks in older people, and excessive adipose tissue relative to underlying bony landmarks in those with a high Body Mass Index (BMI).5 A nerve may have reduced elasticity and mobility without producing any symptoms. This reduction can be caused by adhesions in the neural tissues or surrounding tissue, which can reduce the mobility of the nerve in its bed. Also, increased volume of interface in overweight individuals may result in decreased sliding of nerves and flexibility is reduced in increased body mass index individuals. There is association between obesity and increased nerve size which suggests endoneurial oedema as a metabolic mechanism that causes intrafascicular swelling.7

II. AIMS AND OBJECTIVE

1. Aim: To review the literature available on association of BMI with neurodynamics.
2. Objectives: To Search the articles using search engines like Google Scholar, ovoid, SAGE, PUBMED, Springer Link, Cochrane, Science Direct, EBSCO Discovery Service, and Web of Science database.

III. MATERIAL AND METHODOLOGY

This narrative review of literature pertaining role in association of BMI with neurodynamics in healthy adults. Keywords were finalized i.e. neurodynamic tests, BMI, weight, ULTT.

After finalizing the keywords, the literature search was done using various search engines such as Google Scholar, PubMed, ovoid, SAGE, springer link, EBSCO, Discovery service, and web of science database, etc. whenever possible hand search of articles was done in University library and research centre.

The criteria for the inclusion of articles were studied and reports that provide data on association of BMI with neurodynamics in healthy adults. All types of studies like systematic review, meta- analysis, randomized control trials, case series were included. The article published in the English language and having good level of evidence was included in the study.

IV. RESULTS

After finalizing various keywords, and with the help of the search strategy 20 studies were identified from multiple databases. Following the removal of duplicates and the screening of titles and abstracts, a total of 14 potentially relevant studies remained. These studies were reviewed according to inclusion criteria to determine if they should be reviewed, 8 studies remained other 6 studies were excluded from the studies because of their lack of explanation of neurodynamics and BMI.

Searching key words database identification

V. TABLE

VI. DISCUSSION

From the review of 2 articles neural tissue extensibility was reduced in over weight and obese patients (back pain) as compared to patients(back pain) having normal and underweight BMI and neural tissue extensibility was affected in overweight young adults as compared to age matched normal young adults.

Same studies stated increased volume of interface in overweight individuals result in decreased sliding of the nerves and flexibility is reduced in individuals with increased body mass index.

Review from other 6 articles stated the correlation of nerve conduction with BMI. These studies found correlation of nerve conduction with gender, age, height, and weight. But Weight shows a substantial correlation with latencies of F-wave and H reflex, where individuals with higher body weights have longer latencies of the median, peroneal, tibial F-wave, and H reflex studies compared to those with lower body weights. There is correlation between increased BMI and lower sensory/mixed nerve amplitudes should be taken into account in clinical practice.

Thus, there is influence of adipose tissue in the epineurium is related to some extent to the amount of body fat, it is conceivable that the amount of such fat affect the conduction of the nerves.

VII. FUTURE IMPLICATION

Further studies can be carried out to establish direct correlation of BMI with ULTT and SLR.

Conclusion

There is significant correlation of BMI with neurodynamic tests (slump test and nerve conduction studies)

References

[1] D. SCOTT DAVIS et al “Upper Limb Neural Tension and Seated Slump Tests: The False Positive Rate among Healthy Young Adults without Cervical or Lumbar Symptoms” THE JOURNAL OF MANUAL & MANIPULATIVE THERAPY 2008 Jun 1;16(3):136-41. [2] Johnson EK, et al The slump test: the effects of head and lower extremity position on knee extension. Journal of Orthopaedic & Sports Physical Therapy. 1997 Dec;26(6):310-7. [3] Chi-Ren Huang et al Effects of Age, Gender, Height, and Weight on Late Responses and Nerve Conduction Study ParametersActa Neurol Taiwan 2009;18:242-249. [4] RALPH M. BUSCHBACHER, Body mass index effect on Common nerve conduction Study measurements.John Wiley & Sons, Inc. Muscle Nerve 21: 1398–1404, 1998. [5] Khan AM, Sheth MS, Vyas NJ. Comparison of effect of different sensitizing maneuvers on Slump test in patients with low back pain having normal and overweight Body Mass Index International Archives of Integrated Medicine, Vol.2, Issue 4, 2015. [6] Meenakshi Venkateswaran et al “comparison of effect of different sensitizing manoeuvres on slump test between normal and overweight young adults”. Indian Journal of Physiotherapy & Occupational Therapy. January-March 2014, Vol. 8, No.1 . [7] Mark e. LANDAU et al effect of body mass index on ulnar nerve conduction velocity, ulnar neuropathy at the elbow, and carpal tunnel syndrome 2005 Wiley periodicals.

Copyright

Copyright © 2023 Chandani Z, Dhwani C. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.