intensely all year, with few breaks.]]> rehabilitation exercises before they can return to sports.]]> surge actually helps them increase muscular power and control, allowing them to better handle the rapid skeletal growth.]]> degenerative knee osteoarthritis than those who never had an ACL injury.]]> lax.]]> hormones also make the ligaments more lax.]]> tissues, or ligaments - the anterior cruciate ligament (ACL), which runs diagonally across the knees and attaches muscle to bone.]]> testosterone surge actually helps them increase muscular power and control, allowing them to better handle the rapid skeletal growth.]]> injuries to one of the knee's four major connective tissues, or ligaments - the anterior cruciate ligament (ACL), which runs diagonally across the knees and attaches muscle to bone.]]> femur bones.]]> tibia and femur bones.]]>