Respostas cinemáticas e eletromiográficas durante suporte parcial de peso em indivíduos saudáveis

Abstract

Partial weight support (PWS) is an intervention method that allows a decrease in body weight by a suspension apparatus, which accommodates elevations and body falls during treadmill walking. It is frequently prescribed for individuals with movement disorders whose treatment programs aims to decrease the loads in the tissues, promoting joint protection and pain relieve. However, little is known about the actual repercussions generated in gait when partial weight support is used. Thus, the present study aimed to verify the effect of speed and PWS on kinematic and electromyographic variables of healthy individuals. Forty nine healthy subjects (18 women), with 28.7 (± 6.7) years of age, body mass of 76.9 (± 14.9) kg, height of 173.3 (± 14.9) took part of the study. They walked in a treadmill at 3 different velocities (2.0 km/h, 4 km/h and at a self-selected pace), and under 4 levels of partial weight suspension: 0%, 20%, 50% and 80%. All volunteers went through the 12 conditions. We found that PWS above 50% at low velocities and at self-selected pace the gait cadence decreases, the balance phase increases, articular amplitudes and hip, knee and ankle peaks decrease. Higher PWS induced a decrease in the electromyographic activity in gluteus medius, rectus femoris, vastus lateralis, biceps femoris, tibialis anterior and lateral gastrocnemius muscles in all gait phases. These results suggest that the suspension has a direct influence in the gait behavior of healthy individuals. It decreases muscle and joint demands without changing its main characteristics, allowing the use of this strategy for joint protection and early return to independent locomotion.