Electromyographic activity of the erector spinae: The short-effect of one workday for welders with nonspecific chronic low back pain, an observational study.

Objective: This study aimed to evaluate the effect of one workday on pain and perceived exertion, muscular strength, and electromyographic activity of the erector spinae muscles in welders with and without low back pain. This is an observational cohort study.

Participants: Twenty-two welders, metallurgical shipbuilding, were equally divided into 2 groups: low back pain and no low back pain.

Interference of Different Types of Mastication on Static Balance in Individuals without Temporomandibular Disorder.

Purpose: This study was to determine whether non-habitual (isotonic) bilateral and unilateral mastication with eyes open and eyes closed exerts an influence on static balance in individuals without temporomandibular disorder (TMD).

Method: An observational, cross-sectional study was conducted involving 20 volunteers aged 20 to 40 years without temporomandibular disorder. Static balance was assessed with the individuals in a quiet standing position on a force plate performing different types of mastication under six separate conditions.