How would range and strength of abduction of the upper extremity be affected if there were a rupture of the coracoclavicular ligament?

What will be an ideal response?

ANS:
Without the coracoclavicular ligaments, the only force causing elevation of the clavicle would be the direct action of the upper trapezius. That is, the indirect force for clavicular elevation would be lost because the scapula would immediately upwardly rotate around the acromioclavicular (AC) joint. Further, there would be no force to create clavicular rotation, because this motion occurs only through the mediation of these ligaments. Given that some clavicular elevation would occur through the direct action of the upper trapezius, and at least some s-t upward rotation would occur directly at the AC joint, an approximation of 30 ° to 40 ° of scapular rotation would appear feasible. The total range available actively and passively is 150 ° to 160 °.