Acute<unk> s typically occur when the joint is abruptly forced beyond its functional range of motion, often in the setting of trauma or sports injuries. Chronic<unk> s are caused by repetitive movements leading to overuse. Mechanism Ligaments are collagen fibers that connect bones together, providing passive stabilization to a joint. These fibers can be found in various organizational patterns (parallel, oblique, spiral, etc.) depending on the function of the joint involved. Ligaments can be extra-capsular (located outside the joint capsule), capsular (continuation of the joint capsule), or intra-articular (located within a joint capsule). The location has important implications for healing as blood flow to intra-articular ligaments is diminished compared to extra-capsular or capsular ligaments. Collagen fibers have about a 4% elastic zone where fibers stretch out with increased load on the joint. However, exceeding this elastic limit causes a rupture of fibers, leading to a<unk> . It is important to recognize that ligaments adapt to training by increasing the cross-sectional area of fibers. When a ligament is immobilized, the ligament has been shown to rapidly weaken. Normal daily activity is important for maintaining about 80–90% of the mechanical properties of a ligament. Risk factors * Fatigue and overuse * High-intensity contact sports * Environmental factors * Poor conditioning or equipment *Age and genetic predisposition to ligament injuries * Lack of stretching or "warming up", which when performed properly increases blood flow and joint flexibility right
Sprain
Bone fracture
Back injury
Strain (injury)
Back strain
Swayback
Whiplash 
Whiplash