 It has been suggested that chimpanzee knuckle-walking and gorilla knuckle-walking are biomechanically and posturally distinct.
<fluency>  It has been suggested that chimpanzee knuckle-walking and gorilla knuckle-walking are biomechanically and posturally distinct.
 It has been suggested that chimpanzee knuckle-walking and gorilla knuckle-walking have been suggested to be biomechanically and posturally distinct.