Editing Sprain (section)

=== Mechanism ===
[[Ligament]]s are [[collagen]] fibers that connect [[bone]]s 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).<ref name=":3" /> The location has important implications for healing as blood flow to intra-articular ligaments is diminished compared to extra-capsular or capsular ligaments.<ref>{{Cite journal|last=Frank|first=C. B.|date=June 2004|title=Ligament structure, physiology and function|journal=Journal of Musculoskeletal & Neuronal Interactions|volume=4|issue=2|pages=199–201|issn=1108-7161|pmid=15615126}}</ref>

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 sprain. It is important to recognize that ligaments adapt to training by increasing the cross-sectional area of fibers.<ref>{{Cite journal|last1=Doschak|first1=M. R.|last2=Zernicke|first2=R. F.|date=March 2005|title=Structure, function and adaptation of bone-tendon and bone-ligament complexes|journal=Journal of Musculoskeletal & Neuronal Interactions|volume=5|issue=1|pages=35–40|issn=1108-7161|pmid=15788869}}</ref> 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.<ref name=":3" />