When seated the spinal load is graeter then when standing.
Certainly, but would the spinal load be greater on this machine compared to if they were just seated in general? I know it wouldn't be comparable to having 200lbs on his back.
But, who ever sits on those things properly?
Anyone who wants to work out with me.
Also, the tilted back posture of that chain may allow the pelvis to posteriorly tilt (if the hamstrings are tight), causing lumbar flexion which may be a position that increases pain for him (or it might not....case specific).
The olympic lifts, if done improperly, could also lead to injury. 