The firing pattern of low-threshold motor units was examined in the human trapezius and first dorsal interosseous (FDI) muscles during slowly augmenting, low-amplitude contractions that were intended to mimic contractile activity in postural muscles. The motor unit activity was detected with a special needle electrode and was analyzed with the assistance of computer algorithms. The surface elec...

CONTEXT Handheld dynamometry (HHD) is considered an objective method of measuring strength, but the reliability of the procedure can be compromised by inadequate tester strength and insufficient stabilization of the dynamometer especially, for the scapular muscles. OBJECTIVE Primarily, to determine the intrarater reliability of HHD when testing shoulder and scapular muscle strength, and secon...

OBJECTIVE To evaluate muscle activation patterns in selected scapulohumeral muscles in the tennis serve. These patterns of muscle activation have not been evaluated in other studies of the tennis serve. Fine wire and surface EMG was used to calculate onset and offset timing of muscle activation. DESIGN Controlled laboratory study. SETTING Biomechanical laboratory. SUBJECTS 16 tennis playe...

The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses g...

[Purpose] The present study examined the effects of treatment using PNF extension techniques on the pain, pressure pain, and neck and shoulder functions of the upper trapezius muscles of myofascial pain syndrome (MPS) patients. [Subjects] Thirty-two patients with MPS in the upper trapezius muscle were divided into two groups: a PNF group (n=16), and a control group (n=16) [Methods] The PNF grou...

Focal posttraumatic shoulder dystonia is a rare and not easily identifiable entity. Its true pathophysiologic nature, predisposing factors, and disease course remain debatable.This article describes a rare case of a 40-year-old man with late symptoms of focal shoulder dystonia after peripheral trauma of his left shoulder girdle. The shoulder was indirectly injured from the impact of a fall off ...

BACKGROUND The purpose of this study was to compare the effectiveness of the trapezius squeezing test with that of the jaw thrust maneuver as clinical indicators of adequate conditions for laryngeal mask airway (LMA) insertion in adults under sevoflurane anesthesia. METHODS One hundred adult patients of ASA physical status 1 or 2 undergoing minor surgical procedures were randomly allocated to...

OBJECTIVE The aim of this study was to compare the interstitial concentrations of pyruvate, lactate and glutamate in the trapezius muscle between patients with fibromyalgia syndrome and healthy controls. DESIGN Comparative cross-sectional study. SUBJECTS Patients with fibromyalgia (n = 19) and healthy controls (n = 19); all women. METHODS Subjects answered a questionnaire about different ...

OBJECTIVE The purpose of this study was to test the hypothesis that wearing a wrist splint while performing a common light manufacturing task (moving an object from a bin) increases shoulder muscle activity. METHODS Electromyography (EMG) signals were evaluated from the anterior, middle, and posterior deltoid, trapezius, supraspinatus, and infraspinatus of 14 volunteers while they moved an ob...

OBJECTIVE The purpose of this study was to determine the response of the cervical muscles to increasing low-velocity anterolateral impacts with the volunteer's trunk flexed to the right and left. METHODS A total of 20 healthy volunteers were subjected to left anterolateral impacts of 4.0, 7.6, 10.7, and 13.4 m/sec and, sequentially, with trunk flexed either left or right. Bilateral electromyo...