The Effects of Whole Body Vibration on Low Back Pain During and After a Military Foot March and Foot March Performance

Abstract

Background: Military foot marches are a critical part of operational missions and military training. However, increases in load carriage weight has increased the amount of musculoskeletal injuries (MSI) sustained. MSI from foot marches now account for 17 to 22 percent of all active duty injuries in the US Army. Weight carried during military foot marches are primarily carried on the service members back; thus a majority of these injuries occur to the back, specifically the lower back. Whole body vibration (WBV) has been shown to decrease low back pain in patients with chronic low back issues by increasing core muscle activation and proprioception. Specific aims of the current study are to determine if WBV and/or core exercise training: 1) influences low back pain during and/or after a military foot march; 2) impacts core muscle activation during a military foot march; 3) affects trunk flexion posture during a military foot march; and 4) influences performance time on a military foot march. Methods: A randomized control trial with three groups: WBV and exercise (WBVEx), exercise (Ex) and a control group was used to evaluate the effects of WBV and exercise on measures of low back pain, performance and recovery during an eight kilometer foot march. Outcome measures: Dependent variables included visual analog scale (VAS), time, creatine kinase (CK), interleukin-6 (IL-6), algometer, posture, electromyography (EMG), heart rate, muscle oxygenation and rate of perceived exertion (RPE). Regardless of group, low back pain, heart rate, muscle oxygenation, and posture increased throughout the weighted foot march. CK and IL-6 increased following the foot march, however only CK remained elevated 48 hours after the foot march. The WBVEx and Ex group increased performance on foot march two (FM2) as compared to the control group. Additionally, the WBVEx and Ex interventions had a moderate effect on increasing pain pressure threshold following FM2 as compared to foot march one (FM1). WBVEx significantly increased posture during FM2. Overall, WBV and/or exercise training may significantly improve foot march performance, posture and increase pain pressure threshold in the low back following a foot march. Additionally, completing multiple foot marches may decrease low back pain associated with foot marches.