Transcutaneous Electromagnetic Stimulation (TENS) uses analgesic currents and while its mechanism of action is not completely understood it is thought that it serves to release endogenous opiates in specific areas of the Central Nervous System (Herrera-Lasso 1993). Pulsed Electromagnetic Field Therapy is thought to improve vascularisation, so promoting healing (Binder 1984). In practice, patients with shoulder pain seldom receive a single treatment intervention in isolation.