Man's thumb can be in the opposite direction of the other fingers of the same hand which gives him much more dexterity. Man's feet are more adapted to the upward position.
"The chimpanzee hand is notably different from the human hand in the relative length of its digits. The chimp thumb is much shorter than in humans, phalanges exhibit much more robust insertion areas for flexor tendons, and metacarpals have transverse ridges across their heads that limit dorsiflexion."
"The primary difference between the human and chimp foot is the contrast between prehensile functions of the ape foot and the anatomy of bipedal striding in the human. The chimpanzee foot has an opposable hallux and long phalanges. The human foot has greatly reduced digits, with all metatarsals parallel and an increase in the lever arm of the tarsus for striding. In the human foot, a longitudinal arch provides a shock absorbing and weight distribution system. The orientation of the ankle joint allows the tibia to take a straighter path over the foot during walking."