The Effects of Spinal Manipulation on Central Nervous System Activity Measured by Reflexive Calf Muscle Recruitment

April 17, 2017 updated by: Grant Sanders

The Effects of Spinal Manipulative Therapy on Postactivation Potentiation

This study investigated the effects of spinal manipulation on central nervous system activity. The presence of postactivation potentiation, an increase in muscular force production following prior muscular contractions, was measured with electromyography and the muscular force production during electrically-induced calf muscle reflexes. It was hypothesized that significantly greater potentiation would be stimulated by a calf muscle contraction with spinal manipulation delivered immediately beforehand than the potentiation arising from the contraction only.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

A randomized, controlled, single-blind crossover study design was utilized, and the three independent variables were spinal manipulative therapy (SMT), a 10 second plantar flexion maximal voluntary isometric contraction (MVIC) or SMT immediately preceding the MVIC (SMT + MVIC). The treatment order was randomized for each of the three sessions before the tibial nerve Hmax/Mmax stimulation protocol.

Each of the four dependent variables were evoked during the tibial nerve H-reflex stimulation protocol at the conclusion of each session, and included the Hmax/Mmax ratio (%) of the gastrocnemius and soleus muscles and the isometric twitch torque occurring at Hmax and at Mmax. Hmax, the highest H-reflex amplitude, is an indication of the greatest possible reflex activation; as such, it is an estimate of the number of motor neurons a subject is capable of activating in a given state. Further increases in the stimulation intensity cause the subsequent M-wave to reach its highest amplitude, Mmax. Mmax is a compound muscle action potential (CMAP) which represents full muscle activation. Specific to the current investigation, Mmax indicated activation of the total volume of the gastrocnemius/soleus motor neuron (MN) pool.

Given that Hmax is an inference of the number of MNs being recruited, and Mmax constitutes the entire motor neuron pool, the proportion of the entire MN pool capable of being recruited can be estimated with the Hmax/Mmax ratio. The Hmax/Mmax ratio was determined by division of the EMG peak-to-peak amplitudes (mV) evoked at Hmax by the preceding Mmax EMG peak-to-peak amplitudes. Differences in each of the four dependent variables (Hmax/Mmax ratios of the gastrocnemius and soleus and the peak twitch torques evoked at Hmax and Mmax) following each treatment form of SMT, MVIC or SMT+MVIC delivered during the three data collection sessions on three separate days were determined with a two-way (treatment × time point) repeated measures ANOVA. Percent changes from baseline were also calculated for each of the dependent variables, and the same type of ANOVA was used to determine differences in the within-subjects effects of each treatment.

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Kentucky
      • Lexington, Kentucky, United States, 40506
        • College of Education, Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 35 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • At least one year of resistance training experience and current completion of at least three training sessions per week
  • Males needed to be able to back squat a minimum load of 1.5 x body weight
  • Females needed to be able to back squat 1 x body weight

Exclusion Criteria:

  • Any pain in the lower back, abdomen or legs and/or surgeries performed in these regions

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: BASIC_SCIENCE
  • Allocation: RANDOMIZED
  • Interventional Model: FACTORIAL
  • Masking: SINGLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
ACTIVE_COMPARATOR: Spinal Manipulation SM
In a repeated measures, crossover design, all subjects received one of three randomized treatments during three separate sessions: SM; a 10 second plantar flexion maximal voluntary isometric contraction (MVIC) or the manipulation immediately preceding the contraction (SM+MVIC).
Procedure: Spinal Manipulation
Manual, side-posture, high-velocity low-amplitude spinal manipulation targeting the lower lumbar spine and sacroiliac joints
ACTIVE_COMPARATOR: Max Voluntary Isometric Contraction MVIC
In a repeated measures, crossover design, all subjects received one of three randomized treatments during three separate sessions: SM; a 10 second plantar flexion maximal voluntary isometric contraction (MVIC) or the manipulation immediately preceding the contraction (SM+MVIC).
Procedure: Max Voluntary Isometric Contraction
A 10 second plantar flexion maximal voluntary isometric contraction
ACTIVE_COMPARATOR: SM+MVIC
In a repeated measures, crossover design, all subjects received one of three randomized treatments during three separate sessions: SM; a 10 second plantar flexion maximal voluntary isometric contraction (MVIC) or the manipulation immediately preceding the contraction (SM+MVIC).
Procedure: SM+MVIC
The spinal manipulation immediately preceding the maximal voluntary isometric contraction

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in H-reflex amplitudes of the gastrocnemius and soleus muscles compared to baseline
Time Frame: Data were collected at 17 time points during a 20-minute tibial nerve electrical stimulation protocol post-treatment: 20 seconds, 40 seconds, 1:00, 2:00, 3:00, 4:00, 5:00, 6:00, 7:00, 8:00, 9:00, 10:00, 12:00, 14:00, 16:00, 18:00 and 20:00 minutes
Peak-to-peak EMG amplitudes (mV) at Hmax of the gastrocnemius and soleus were recorded before and immediately following the three separate treatments
Data were collected at 17 time points during a 20-minute tibial nerve electrical stimulation protocol post-treatment: 20 seconds, 40 seconds, 1:00, 2:00, 3:00, 4:00, 5:00, 6:00, 7:00, 8:00, 9:00, 10:00, 12:00, 14:00, 16:00, 18:00 and 20:00 minutes
Changes in isometric twitch torques of the gastrocnemius and soleus muscles compared to baseline
Time Frame: Data were collected at 17 time points during a 20-minute tibial nerve electrical stimulation protocol post-treatment: 10 seconds, 30 seconds, 50 seconds, 1:30, 2:30, 3:30, 4:30, 5:30, 6:30, 7:30, 8:30, 9:30, 11:00, 13:00, 15:00, 17:00 and 19:00 minutes
Twitch torques (Nm) of the gastrocnemius and soleus at Mmax were recorded before and immediately following the three separate treatments
Data were collected at 17 time points during a 20-minute tibial nerve electrical stimulation protocol post-treatment: 10 seconds, 30 seconds, 50 seconds, 1:30, 2:30, 3:30, 4:30, 5:30, 6:30, 7:30, 8:30, 9:30, 11:00, 13:00, 15:00, 17:00 and 19:00 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Grant Sanders

Collaborators

University of Kentucky

Investigators

  • Principal Investigator: Grant D Sanders, D.C., Ph.D., College of Education, Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY
  • Study Chair: James W Yates, Ph.D., College of Education, Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2014

Primary Completion (ACTUAL)

October 1, 2014

Study Completion (ACTUAL)

October 1, 2014

Study Registration Dates

First Submitted

July 13, 2016

First Submitted That Met QC Criteria

July 25, 2016

First Posted (ESTIMATE)

July 28, 2016

Study Record Updates

Last Update Posted (ACTUAL)

April 19, 2017

Last Update Submitted That Met QC Criteria

April 17, 2017

Last Verified

April 1, 2017

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 14-0507-F6A

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Shared data include the subjects' reflexive EMG amplitudes and peak torques of the gastrocnemius and soleus during the Hoffmann Reflex electrical stimulation protocol at the conclusion of each data collection session. These raw data are available in Appendix K of the PI's dissertation, which may be obtained at http://uknowledge.uky.edu/khp_etds/27/

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Subluxation of Joint of Lumbar Spine

Clinical Trials on Spinal Manipulation

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Israel

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe