This study is completed and is now awaiting publication.

At this stage we cannot print the study in its entirety but we may explain how the study was conducted and by whom. Key findings are also shown here with the kind permission of both Universities.

Prof. Dr. Wim Dankaerts, PhD, MT, PT

Musculoskeletal Research Unit

University of Leuven

In cooperation with

Kieran O'Sullivan SMISCP MISOM M Manip Ther

Lecturer in Physiotherapy,

Faculty of Education and Health Sciences,

University of Limerick, Ireland

Introduction

This study aimed to compare trunk muscle activity and spinal posture when sitting in a standard office chair compared with sitting in a new novel dynamic seat.

Methods

1. Muscle activity was measured using non-invasive surface electromyography (EMG); the Motion Lab Systems MA-300 multi-channel EMG system. The activity of the major lower back and abdominal muscles was measured. Bipolar electrodes were placed on these muscles. Electrodes were adhered to the skin using adhesive tape. EMG was expressed relative to maximal voluntary contraction (MVC) for each subject.

2. Posture was measured using a 'spinal positioning monitoring device' (www.sels-instruments.be). Posture was expressed relative to full range of motion.

TESTING PROTOCOL

15 healthy pain free subjects were tested. Subjects completed both a typing task and a series of office tasks (being on phone, moving paper on desk) in each of the following postures;

(i) Usual sitting on standard office chair (without back support)

(ii) Back App – on green setting (relatively stable)

We also examined posture and muscle activation with;

1. The Back App when set in the red zone, to evaluate what happens in this training mode.

2. subjects in usual standing

3. subjects lying down (resting muscle tone)

4. subject sitting fully slumped

5. subject sitting fully upright

Finally, to see if the backapp could facilitate lumbar lordosis with greater ease / comfort, we asked subjects to obtain a lordosis while on the backapp and while on a standard chair, and see which was more comfortable. Posture and emg measured in both of these again.

When using the backapp the hip angle was standardised to 125 degrees.

Key findings

• Just sitting on backapp makes posture less flexed than on chair with no back support (approx 20% less flexion,)

• Baseline sitting on backapp was more flexed than backapp during typing

• During typing task, subjects sat very close to neutral spine on backapp, without being asked to (25% less flexion than on chair with no back support)

• During typing task, less back muscle activity on backapp (36-54% less active on backapp)

• Office task: backapp was less flexed also, and allows greater range of motion

• When asked to maintain a “good” posture, backapp required 21% less “effort” and significantly less (44%) muscle activation