Proprioceptive impairments cause for concern in low back pain
MedWire News: Patients with low back pain (LBP) may find it difficult to go from sitting to standing and vice versa because of decreased use of lumbar proprioceptive afference, researchers suggest.
This impaired proprioceptive control was associated with a decrease in pelvic preparatory movement in patients with LBP and an increased time to transition between sitting and standing.
"The association between a longer duration of the STSTS [sit-to-stance-to-sit movement] and altered kinematics of the pelvis demonstrated in this study may be a risk factor to develop or sustain LBP, due to the daily frequently performed STSTS in a working population," say Kurt Claeys (Faculty of Kinesiology and Rehabilitation Sciences, Leuven, Belgium) and colleagues.
The team studied the proprioceptive steering of 20 healthy individuals and 106 patients with mild LBP during standing muscle vibration and five STSTS repetitions performed on a stable support and foam.
During standing muscle vibration, patients with LBP relied more on ankle muscle proprioceptive inputs than back muscle proprioceptive inputs compared with healthy individuals.
Moreover, patients with LBP took longer to complete the five STSTS repetitions on a stable support than controls, at an average of 9.33 seconds versus 8.29 seconds. This longer duration was mainly due to longer stance phases (average 1.20 vs 1.08 seconds).
The findings were similar when the movement was performed on the foam support, with the exception of the delayed performances of patients with LBP being due to both longer stance and sit phases.
The duration of the focal movement phases were similar between the two groups.
The researchers also found that the onset of pelvic rotation initiation to start both movement sequences and to move from sit-to-stance on foam was delayed in patients with LBP compared with controls.
They suggest in the Journal of Electromyography and Kinesiology that this delay in anterior pelvic rotation initiation may result in more trunk flexion during the STSTS movement, which combined with mild compressive loads is an important risk factor in the development of intervertebral disc injuries.
To rehabilitate proprioceptive impairments in the lumbosacral region, Claeys et al recommend exercises stimulating people to rely more on back muscle proprioceptive inputs in postural control, performing postural control exercises on unstable surfaces and in different postural conditions, retraining dynamic movements, and performing pelvic control exercises during movement.
"Optimal pelvic control, especially during preparatory or transition phases of these movements… could be fruitful in rehabilitation and/or prevention of reoccurrence of LBP," the team concludes.
By Lucy Piper