Stretching involves deliberately expanding muscles to improve elasticity and flexibility. It's a natural activity performed by humans and animals, including spiders. Can occur after sleep, inactivity or entering confined spaces
Elbow is the region between upper arm and forearm surrounding elbow joint. Joint allows forearm and hand movement towards and away from body. Elbow is specific to humans and primates, not other vertebrates. Joint capsule surrounds three bones: humerus, radius, and ulna
Defecation eliminates waste from digestive tract via anus or cloaca. Peristalsis moves fecal matter through colon to rectum. External anal sphincter is voluntary, internal is involuntary. Frequency varies from few times daily to weekly
Erector spinae muscles straighten and rotate the back. Works with glutes to maintain stable posture. Runs from sacrum to base of skull along spine. Covered by thoracolumbar fascia in lower regions
The knee is the largest joint in the body and is easily injured. Three main bones: tibia, femur, and patella are connected. Articular cartilage covers bone ends, meniscus acts as shock absorber. Fabella, a sesamoid bone, is present in about 25% of population
Skinnier wrists help emphasize forearm muscles, making them appear bigger. Stretch wrists before and after exercises. Warm up with unweighted wrist movements before training. Be patient and consistent in training routine