The University of Edinburgh has recently published “Effect of water depth on muscle activity and stride duration when walking in the water at different speeds”.

The University of Edinburgh were one of the earliest adopters of the Mini Wave Infinity Waterproof by EMG developer Cometa. This special version of Mini Wave Infinity is equipped with a fully waterproof coating, special rubber gaskets and custom remote controller for asynchronous acquisitions. These accessories allow the acquisition of EMG signal underwater, making it as simple as a regular acquisition.


Aquatic exercise is popular for training and rehabilitation, but information on how the water depth affects muscle activity when walking is lacking. The purpose of this study was to compare muscle activity when walking on land and at knee, pelvis and xiphoid process depth in a swimming pool. Twelve participants (22±3.6 years; 70.9±14.5kg; 1.7±0.1m) walked on land and on the pool floor at each of the three depths, at a self-selected (Vself) and a maximum speed (Vmax). Mean and peak muscle activity was recorded for the rectus femoris (RF), biceps femoris (BF), medial gastrocnemius (GM), lateral gastrocnemius (GL), tibialis anterior (TA) and erector spinae (ES). Stride duration was also recorded. Stride duration decreased and activity of all muscles increased from Vself to Vmax, except peak values at xiphoid process depth. For the depth comparisons, most changes in muscle activity occurred in the RF and BF, with higher values generally occurring at knee and pelvis depth, and stride duration continually increased with depth. These findings provide useful information on the musculoskeletal demands of walking in the water that can be used to inform design and prescription of exercise programmes for rehabilitation.

For the full paper please click here.