The hypothesis of this study was the potential of whole body vibration, performed on the Power Plate® machine, in a therapeutic context, where it may enhance muscular performance in patients and older adults for whom standard exercise programs are not an option. Maintaining muscle mass, functional strength and cardiovascular performance is a challenge for the elderly due to the risk of potential overload and the diminished ability of the aging body to adapt to high levels of loading. Whole body vibration provides a safe and easy opportunity to train these systems without excessive overload.
Muscle strength and peak muscle power have a great influence on the function of older adults in activities of daily life such as walking, climbing stairs, and rising from a chair. Common risk factors leading to falls and hip fractures in older adults are muscle weakness and the inability of lower extremity muscles to produce rapid force. Older adults lose muscle mass with an age-related decrease in physical activity. Therefore, the prevention of age-related strength loss and muscle atrophy is a public health issue.
The research included 89 postmenopausal women between the ages of 58 and 74. Participants were randomly assigned to three groups: the whole body vibration group trained three times per week on a Power Plate® machine; they performed a progressive program of static and dynamic knee extensor exercises such as squats and lunges. The conventional training group also trained three times per week; they performed dynamic leg press and leg extension exercises on conventional fitness equipment, increasing intensity from low to high resistance. The control group did not participate in any training for the entire duration of the study, which was 24 weeks.
The results prove that both whole body vibration and conventional training increases muscle strength of the legs (figure 1). Both groups also showed an improvement in performing the counter movement jump (figure 2). The speed of movement increased only for the group that trained on the Power Plate® machine (figure 3).
The counter movement jump is an accurate method for measuring the stretch shortening of the muscles, a system used in daily life in acitivities such as rising from a chair, climbing a stair or maintaining balance. Speed of movement is a very important measure of reaction and balance, and plays a part in reducing the risk of falling.