Abstract
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);
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at the same load and
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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.
Correspondence should be addressed to: Mr John O’ Dowd, SBPR, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
