Three-dimensional analysis of the pelvic and hip mobility during gait on a treadmill and on the ground.

Pelvic girdle combines two units: passenger and locomotor. That is why the importance of this part of the body is emphasized by all researchers in terms of gait economy. The purpose of our research was to determine the changes of pelvic girdle mobility and hip joint in men in three planes of movement (sagittal, frontal and horizontal) during gait at a speed of 5 km/h. The methodology used here aimed at assessing the impact of the surface (ground or treadmill) on the mobility in those planes. To register overground and treadmill locomotion we applied: Vicon 250, Cardionics Treadmill 3113. The sample of the study was the group of 30 men aged between 21 and 23. The analysis of the results revealed the biggest impact of the type of surface on both pelvis and hip joint in the transverse plane. When the subjects moved on the natural ground, the pelvic range of motion (ROM) in this plane was more than twice wider than that in treadmill walking. Whereas in the case of hip joint, significantly higher ROM values occurred in the transverse plane during walking on the treadmill.

Influence of surface on kinematic gait parameters and lower extremity joints mobility.

In biomechanical studies of human locomotion, treadmill is a widely used measuring device. The purpose of this paper was to determine the values of kinematic parameters describing gait with the velocity of 5 km/h, both on the ground and on a treadmill. Besides, the authors assessed the impact of the surface on the mobility of three main joints of lower extremities in the sagittal plane. The measurements were done on a sample of 48 men aged between 21 and 23. The most important element of a measuring set was the Vicon system. Based on kinematic parameters our data indicated that during walking on a treadmill step frequency was slightly higher than that on the ground. Probably, due to that fact there were found some differences in other variables (e.g., single support as well as step and stride time). Besides, the results revealed that the type of surface affects joint range of motion, in particular ankle plantar flexion, the instantaneous values of joint angles and change in dynamics of these values.

The impact of changes in gait speed and step frequency on the extent of the center of mass displacements.

Center of mass (COM) trajectory plays a crucial role in the analysis of human body movements. This research aimed at studying vertical and transverse COM displacements during gait on a treadmill at a given velocity and step frequency. Locomotion study was accomplished using: Vicon 250, Cardionics Treadmill 3113 and metronome Korg Ma-30. The data achieved for 12 women and 15 men aged 21-22 revealed similarity in vertical COM oscillations in both groups. Lateral COM displacements (L(COM)) were slightly higher in men than in women and they showed tendency to decrease as gait velocity increased. During natural locomotion there was an increasing trend as walking speed increased. At a given velocity of locomotion L(COM) were decreasing as step frequency increased. The only astonishing thing was that the biggest changes of vertical COM oscillations (V(COM)) were noticed at the fastest walking speed (6 km/h). It seems that so large decrease in V(COM) during walking with high velocity and increased step cadency is a consequence of considerable shortening of the movement cycles and performing time of one step.