1. Primate Locomotion

2. Primate Locomotion Some primates are arboreal i.e. live in trees.
Other primates are adapted to life on the ground

3. Arboreal Locomotion Quadrupedalism
walking on all 4 limbs. Arms and legs are more or less equal length and importance. The most primitive form using this method lived in the trees e.g. the lemurs

4. Arboreal Locomotion Modified Quadrupedalism
Leaping and clinging. The animal’s trunk is vertical before and after each leap, as well as in the resting position. On the few occasions when on the ground these primates hop on their back legs or walk with the trunk held upright. (a prerequisite for bipedalism. E.g. some prosimians.

5. Leaping Lemurs
Leaping

6. Arboreal Locomotion Brachiation
this involves the use of arms to suspend the body during feeding and to move the body by arm-swinging. This can be:
Full or Extreme – e.g. gibbons. Progressing rapidly beneath branches using the arms alone, extended above their heads.

7. Brachiation.
Brachiation

8. Arboreal Locomotion
Semi-brachiation – this is less extreme. The hind limbs are still essentially dominant e.g. spider monkeys are quadrepeds about 80% of the time and arm-swing only about 10% of the time. This intermediate stage is a likely precursor stage for bipedalism

9. Ground Locomotion Quadrapedalism
this is walking on all four legs, e.g.baboons

10. Ground Locomotion Knuckle Walking
walking on the backs of the middle parts of the 3rd and 4th fingers on each hand. The fingers, hand, wrist and arm joints are all adapted to this type of locomotion. Which is used in the trees as well as on the ground. The foot shows some parallel trends to ground walking. E.g Chimps and gorillas.

11. Ground Locomotion Habitual Bipedalism
walking on 2 legs i.e. they are plantigrade which means walking on the bottom surface of the whole foot. This involves major changes in the pelvis, backbone and foot. This is exemplified by hominids e.g. humans