who do work that requires them to spend lots of time with their backs bent
should take frequent walking and standing breaks to avoid lower back pain, the
authors of a new study conclude.
Kelvin C.H. Wong of The Hong Kong Polytechnic University used a device called an
accelerometer to track spinal posture in workers at a school for severely
handicapped individuals. All the workers had to spend a considerable amount of
time working in a stooped posture, for example to move students -- most of whom
needed help with activities of daily living -- from place to place.
of the workers had suffered from low back pain for a minimum of one to seven
days in the previous year, while 15 had no back pain problems for the past 12
wore an accelerometer attached to their trunk for three hours in the morning and
another three hours in the afternoon. The device was able to record the degree
to which people's backs had moved out of the upright position, and how much time
they spent in various degrees of back flexion.
Wong and his team found, the people who had back pain were spending more time
with their trunks in the same position compared to people who were pain-free.
They also spent less time with their backs flexed less than 10 degrees, and more
time in three positions in which their backs were bent more than 10 degrees.
thus appears that an increase in risk of back pain may be associated with long
periods of sustained stooped posture," the researchers state in the online
journal BMC Musculoskeletal Disorders.
one's posture frequently and remaining aware of trunk posture can help fight
fatigue and reduce the stress the workers were placing on their backs, Wong and
his colleagues say, adding: "Rest activities such as standing up from
stooping and walking for a short distance are suggested to promote the cyclic
muscular contraction and relaxation that facilitate the nourishment of spinal
tissues and provide periodic rest to the muscles."