[Association between trunk muscle activation and wall inclination during various static climbing positions:...

Sport climbing has been increasingly applied as therapy for patients with orthopaedic problems. Results from previous intervention studies have already revealed positive effects, especially for people with back problems, although there is a lack of baseline knowledge regarding the general effects of climbing. The aim of this present study is to investigate the muscle activation of the trunk while performing various static climbing positions at different inclination angles. SUBJECTS/MATERIAL AND METHODS: Thirteen healthy adults without climbing experience were asked to hold three static climbing positions (base position, lifting a hand, lifting a foot) at three different handhold set-ups and six wall inclination angles (0°, 4°, 8°, 12°, 15°, 18°) for 5 seconds each. Bilateral muscle activity of Erector spinae, Multifidus, Latissimus dorsi, Obliquus externus abdominis, Obliquus internus abdominis and Rectus abdominis was measured using surface electromyography. Data were analysed for each muscle and climbing condition separately.

Compared to the vertical wall, the muscle activity starts to differ significantly (p ≤ 0.05) from 12° onwards. This inclination angle particularly affects the activity of all muscles when lifting a hand (0.000 ≤ p ≤ 0.048). The oblique abdominal muscles did not show any or little effects when lifting a foot or being in the base position, while all other muscles demonstrate a continuous increase. The EMG data were normalised to the corresponding base position and analysed for each muscle and climbing condition separately.

Inclinable climbing walls are an appropriate method to increase muscle activity. Compared to the base position, activation of the oblique abdominal muscles, which are relevant for a stable trunk, is increased only when a hand is lifted. Climbing walls used for therapy should offer variable inclination angles. Further research should concentrate on the development and evaluation of climbing exercises for specific patients (eg people with scoliosis).