Prevention of repetitive stress injuries of the forearm, wrist and hand by use of an ergonomic paint brush
... Humans are plagued by numerous conditions, which can as a group can be called repetitive stress injuries or cumulative micro trauma disorders. Included is this category are "MSD's" or musculoskeletal disorders which refer to conditions that involve the nerves, tendons, muscles and supporting structures of the body.
There are several conditions to consider within the hand and wrist region. Combined work factors of forceful and repetitive use of the hands and wrists are associated with carpal tunnel syndrome. Workers in industries which spend their workdays performing forceful exertions and repetitive movements of the hand and wrist have been found to have a strong association with tendonitis of the wrist and have also been found with disorders of the elbow such as epicondylitis. Carpal tunnel syndrome is usually associated with a) ill-designed tools, poor job techniques and repetitive work processes involving the hands.
My initial analysis began with a review of available research on the subject of musculoskeletal disorders, carpal tunnel syndrome and other reviews of epidemiological evidence for work-related disorders of the hand, wrist and forearm. Here we are interested in those conditions specifically related to repetitive flexion/extension and side bending of the wrist as well as forceful and or prolonged gripping of the fingers. We have chosen these particular activities because they are the movements involved the use of the standard paintbrush. Contained in Table 1 below are some of the most frequent disorders associated with these movements.
Further, research supports the fact that "repeated or continuous contact with hard or sharp objects such as non-rounded desk edges or unpadded, narrow tool handles may create pressure over one area of the body (e.g., the forearm or sides of the fingers) that can inhibit nerve function and blood flow".
NIOSH's publication, Elements of Ergonomics Programs succinctly summarizes as follows: "The affect of repetition on intramuscular tissue, nerves and joints is also an important consideration. A series of motions performed every few seconds with little variation may produce fatigue and muscle-tendon strain. If adequate recovery time is not allowed for these effects to diminish, or if the motions also involve awkward postures or forceful exertions, the risk of actual tissue damage and other musculoskeletal problems will probably increase. A task cycle time of less than 30 seconds has been considered repetitive." (Continued via ) [Ergonomics Resources]