Effects of acupuncture on muscle strength of healthy subjects and stroke patients

INTERVENTION: E02.190.044 E02.190.044.555.035 The intervention will consist in a unique treatment session (day). All subjects from both groups (healthy control and stroke patients) will be in a sitting position with their upper limb supported during all procedure. The following procedure will be performed only once for each subjects: Location of the acupuncture points according to the modern pattern, followed by skin assepsia with 70% alchohol and saline solution hydration; Electrode positioning for recording of the surface electromyogram according to the Surface Electromyography for the Non‐Invasive Assessment of Muscles (SENIAM) protocol for the biceps brachii muscle; Electromyographic signal acquisition during dynamometry; Needle insertion (45º angle) directed to the qi circulation with sterilized, disposable needles (0,20 x 13 mm) at approximately 1.5 cm deepth, followed by rotating maneuvers until the subjects reported the de qi sensation; At 5, 10, 15 and 20 minutes, manual stimulation will be performed during 10 seconds; After 20 minutes, the needle will be withdraw and the signal acquisition repeated. CONDITION: C10.228.140.300.775 C10.597.613.550 Stroke‐related motor impairment ; C10.228.140.300.775 ; C10.597.613.550 PRIMARY OUTCOME: Proportion of individuals with reduced muscle strength. Isometric muscle strength will be measured by the average of three maximal isometric voluntary contractions, each lasting 5 seconds, performed in the interval of 3 minutes each. Proportion of subjects with reduced motor unit recruitment. Muscle recruitment will be measured by the average of RMS values of three maximal isometric voluntary contractions, each lasting 5 seconds, performed in the interval of 3 minutes each. SECONDARY OUTCOME: Prevalence of clinical manifestations in each subtype of clinical presentation. Clinical manifestations will be collected by interview with a clinical questionnaire. Prevalence of subtypes of clinical presentations according to Chinese medicine. Subtypes will be classified by multivariate logistic regression based on the reported symptons. INCLUSION CRITERIA: Control group: Absence of pain, trauma or musculoskeletal injuries in the upper limbs, neuromuscular diseases, pregnancy or some sort of unconfortable reaction to needling; Informed written consent signature after reading of the text and explanation of the objectives, risks and potential benefits from the participation in this research. Hemiplegic group: Clinical diagnosis of upper neuron lesion due to stroke for at least 6 months, confirmed by image exams, both ischemic of hemorragic; Partial motor impairment of the upper limb function (hemiparesis); Absence of pain, trauma or musculoskeletal injuries in the upper limbs, neuromuscular diseases, pregnancy or some sort of unconfortable reaction to needling; Informed written consent signature after reading of the text and explanation of the objectives, risks and potential benefits from the participation in this research.