A new tool in rehab called the Bodyblade has been tested recently with good results. The Bodyblade is a long, thin foil that oscillates (moves back and forth) at a natural frequency of 4.5 Hz. A foil is the thin sword used in fencing or sword fighting.
The speed of the oscillation combined with the position of the user activates trunk and abdominal muscles. The orientation of the blade is also important when using this tool in rehab.
Fourteen (14) healthy athletes were tested using the Bodyblade. Four different exercises were performed to challenge the core trunk muscles. Surface electrodes attached to the skin recorded muscle activation during each exercise. Position of the spine was also tracked using a special electromagnetic device.
Compressive force through the spine and spinal stability were measured using well-known math and computer models. Patterns of muscle activation were identified and analyzed.
The authors report the key to successful use of the Bodyblade literally lies in the hands of the user. It seems only some people are able to master the coordination needed to achieve resonance. Others can not do so no matter how much they practice.
For those who could use the Bodyblade easily, horizontal use resulted in the highest activation levels of trunk and abdominal muscles. Diagonal use resulted in moderate amounts of muscle cocontraction. Cocontraction is the use of muscles on both sides of a joint at the same time.
Patients who could not oscillate the Bodyblade at lower levels of amplitude had greater spinal compression. For this reason, safety may be an issue for some patients.