Isometric pull-push strengths in workspace: 2. Analysis of spatial factors.

The effect of reach levels, horizontal angles and vertical angles on isometric pull and push strengths of males and females in standing and seated positions was determined. The effect of reach levels on strength varied as a consequence of force direction, working position and gender. Reach level has a significant effect on women's pull strength in the seated position and on push strength in the standing position. The strength value was significantly greater in the extreme reach than in maximum or normal reach. Vertical angle phi had a significant effect on strength consistently in all cases. Strength values increased significantly with the increase of phi angles from 0 degrees to 45 degrees to 90 degrees. The horizontal angle theta had a significant influence only on the pull strength of standing and seated men and standing women (not seated woman). The maximum strength was significantly greater at theta = 90 degrees.