The root mean square surface electromyographic activity of lumbar extensor muscles during dynamic trunk flexion and extension from standing has repeatedly been recommended to objectively assess muscle function in chronic low back pain patients.
Extensor muscles
comprises of the group of skeletal muscles whose contraction extends or
stretches the wrist and hand. Age and gender greatly affects the occurrence of
the chronic low back pain (cLBP), also affecting the muscles. The research done
in this topic deals with the neuromuscular regulation and its future prospects
for cLBP.
The root mean
square surface electromyographic activity of lumbar extensor muscles during
dynamic trunk flexion and extension from standing has repeatedly been
recommended to objectively assess muscle function in chronic low back pain
patients. However, literature addressing older patients is sparse. This cross
sectional study sought to examine differences in neuromuscular activation
between age groups (>60 versus 40-60 versus <40 years) and sexes during a
standardized trunk flexion-extension task.
A total of 216
patients (62 older, 84 middle-aged, 70 younger) performed maximum trunk
extensions followed by trunk flexion extension testing thereby holding static
positions at standing, half, and full trunk flexion. The lumbar extensor muscle
activity and 3d-accelerometric signals intended to monitor hip and trunk
position angles were recorded from the L5 (multifidus) and T4 (semispinalis
thoracis) levels. Permutation ANOVA with bootstrapped confidence intervals were
performed to examine for age and gender related differences. Ridge-regressions
investigated the impact of physical-functional and psychological variables to
the half flexion relaxation ratio (i.e. muscle activity at the half divided by
that in maximum flexion position).
Maximum back
extension torque was slightly but significantly higher in youngest compared to
oldest patients if male and females were pooled. Normalized RMS-SEMG revealed
highest lumbar extensor muscle activity at standing in the oldest and the
female groups. Patients over 60 years showed lowest activity changes from
standing to half (increments) and from half to the maximum flexion position
(decrements) leading to a significantly lower half flexion relaxation ratio
compared to the youngest patients. These oldest patients demonstrated the
highest hip and lowest lumbothoracic changes of position angles. Females had
higher regional hip and gross trunk ranges of movement compared to males.
Lumbothoracic flexion and the muscle activity at standing had a significant
impact on the half flexion relaxation ratio.
The neuromuscular
activation pattern and the kinematics in this trunk flexion-extension task
involving static half flexion position changed according to age and sex. The
test has a good potential to discriminate between impaired and unimpaired
neuromuscular regulation of back extensors in cLBP patients, thereby allowing
the design of more individualized exercise programs.
Journal of NeuroEngineering and Rehabilitation (2016) 13:16
Age and gender related neuromuscular pattern during trunk flexion-extension in chronic low back pain patients
Thomas Kienbacher et al.
Comments (0)