Final answer:
A PTA sitting with crossed arms and legs is exhibiting closed posture, which can imply non-openness or defensiveness. Understanding body language is key in non-verbal communication. Good posture is crucial for reducing strain on the body.
Step-by-step explanation:
A PTA sitting with their arms and legs crossed is an example of closed posture. This type of posture can communicate that a person is not open to communication or maybe feeling defensive or self-protective. Body language and posture play a significant role in non-verbal communication and can impact social interactions. Good posture involves proper alignment and positioning of the body, which helps in avoiding strain and potential damage to the musculoskeletal system. When considering posture, it is also important to acknowledge that muscles are attached close to joints and maintaining the center of gravity above the hips helps in reducing back strain.