The functional elbow range of motion in children and adolescents has not been previously reported. In adults, a functional motion arc of 30 to 130 degrees of elbow flexion and 50 degrees of pronation to 50 degrees of supination is well established. Contemporary tasks such as cellular phone use and keyboarding require greater elbow flexion and pronation than the functional motion arc. Whether or not this is true in children has yet to be established. We hypothesize that to perform functional and contemporary tasks, children and adolescents use a greater range of elbow motion and forearm rotation as compared with adults.
Twenty-eight subjects performed 8 functional tasks and 4 contemporary tasks. Kinematic data were captured using a 3-dimensional motion analysis system as previously described. Mean and SD was collected for elbow flexion, extension, pronation, and supination. Unpaired t tests were performed to compare elbow kinematics of children 6- to 11-year-old (n=14) to that of adolescents 12- to 17-year-old (n=14), with a significance criterion of P-value <0.05.
The mean arc of motion to achieve functional tasks was 28 to 146 degrees of elbow extension/flexion and 54 degrees of supination to 65 degrees of pronation. Contemporary tasks utilized 40 to 148 degrees of elbow extension/flexion and 49 degrees of supination to 65 degrees of pronation. A greater supination/pronation arc (107 degrees) and greater elbow flexion (148 degrees) were used to bring a cellular phone to the ear, whereas greater pronation (65 degrees) was used to type on a keyboard. Statistically significant differences were observed between children and adolescents in each of the 12 tasks, with the exception of using a fork.
A motion arc of 30 to 130 degrees of elbow flexion and 50 to 50 degrees of pronation/supination is sufficient to achieve most positional and functional tasks in children and adolescents. However, specific contemporary tasks such as the use of a cellular phone and typing on a keyboard utilize more elbow flexion and pronation. Awareness of greater use of flexion and pronation to achieve contemporary tasks may help guide surgeons in the care of patients with posttraumatic elbow and forearm deformities and contractures.
Level of Evidence:
Level II—investigation of a diagnostic test.