BACKGROUND: Stroke is a morbid entity in Chinese medicine recognized for over 2 000 years with sensory-motor impairments reported by several classical authors. However, the majority of controlled clinical trials of acupuncture in the treatment of poststroke recovery failed to obtain significant long-term results on functional recovery. Moreover, contradictory results have been obtained regarding the immediate effects of acupuncture stimulation on the electrical activity of human skeletal muscles as observed using surface electromyography. These results raise the question of whether acupuncture has any effect on the neuromuscular level. This study aims to evaluate the immediate effects of manual acupoint stimulation on the electrical activity and strength of the biceps brachii of healthy individuals and patients with chronic hypertonic hemiparesis.
METHODS AND DESIGN: The study proposes a single-blinded randomized clinical trial with four parallel groups. Healthy subjects and poststroke patients with chronic spastic hemiparesis will be submitted to a single acupuncture intervention puncturing either Quchi (LI11) or Tianquan (PC2). The immediate effects on muscle function will be assessed by surface electromyography and isometric force of the biceps brachii muscle as the primary outcome. Secondary outcomes comprise the frequency of patterns in each group, as well as the frequency distribution of manifestations.
DISCUSSION: The proposed study design includes some improvements on common methodological issues on clinical trials with an integrative design. This study design is expected to provide new insights on the neuromuscular effects of acupuncture stimulation in healthy subjects and poststroke patients.
TRIAL REGISTRATION: Brazilian Clinical Trials Registry (www.ensaiosclinicos.gov.br) in English and Portuguese in October 2011. Registration number: RBR-5g7xqh.

Key words: acupuncture therapy, poststroke syndrome, movement disorders, electromyography, randomized controlled trials, clinical protocols