An orthotic support comprises a shoulder section for encapsulating a first shoulder of a wearer, a glove section for conforming to at least a portion of the wearer's hand, and a sleeve section for conforming to the wearer's arm, the sleeve section connecting the shoulder section to the glove section. A resilient reinforcement extends from the glove section to the shoulder section, and at least a portion of the reinforcement extends in a spiral around the sleeve section, so that the reinforcement is configured to apply a rotational force to the wearer's arm, when worn, to urge a portion of the wearer's arm to rotate in a predetermined direction. The orthotic support may be usable to treat or prevent shoulder dislocation or subluxation, arm over-pronation or over-supination, wrist flexion or elbow flexion. An orthotic support may comprise a reinforcement with a first branch extending over an anterior portion of the sleeve section, and a second branch extending over a posterior portion of the sleeve section, so that the reinforcement is configured to urge the wearer's upper arm towards a rest position.