Introduction: EMG recording from lumber spine muscles can be a reliable discriminator and predictor of low back pain (LBP). Multi variant analysis shows age influences these variables.
Aim: to determine in a longitudinal study if age is a significant factor.
Method: EMG recording from 9 subjects was carried out at time1 and 12 years afterwards (time 2);
at the same load and
at 2/3 of their current Maximum Voluntary Contraction (MVC).
Results: At the same load there was no significant change in the Mean Half Width (HW) from time1 (M=45.9, SD=19.1) to time 2 (M=51.4, SD=18.7), t(8)= −0.98, p=0.36. No difference was observed when the load set at time 1 was used at time 2 (M=51.4, SD=18.7) and compared with a load set from the MVC obtained at time 2 (M=45.9, SD=12.0), t(8)=1.75, p=0.118.. There was no statistically significant difference between Initial Median Frequency (IMF) at time1 (M=50.6, SD=12.0) and time 2, either using the same load (M=51.7, SD=8.6), t(8)=− 0.273, p=0.79) or the load based on current MVC.
Discussion: In this 12 year longitudinal study, age did not appear to affect the HW or IMF measurement. Both of these variables might be used in long term studies.
