Maximal power of trunk flexor and extensor muscles as a quantitative factor of low back pain

Abstract

Torque-velocity and power-velocity relationships, which determine the different indicators of muscle function, have some practical application during rehabilitation program. These relationships for trunk flexor and extensor muscles during isokinetic conditions have yet to be studied in chronic lower back pain patients in order to demonstrate that maximal power could be used as a quantitative factor for this population. Ten healthy male subjects and eleven chronic lower back pain male patients performed series of isokinetic trunk flexions and extensions at six different velocities, ranging from 45°/s to 120°/s, on a Biodex dynamometer. The torque-velocity and power-velocity relationships of trunk muscles were described by linear (P < 0.01; r=0.9–0.99) and parabolic (P < 0.05; r=0.9–0.99) relationships, respectively. Maximal power was the only parameter which showed a significant difference (P< 0.01) between the two populations for both flexor and extensor muscles. It was concluded that the lower back pain did not influence the shape of trunk muscles' torque- and power-velocity relationships. The different maximal power observed between the two groups suggests that rehabilitation program should focus on strength training for the extensor muscles whereas the flexor group would follow velocity exercise session.

Influence of lower limbs strength on trunk flexion and extension in chronic low back pain patients

“…T 0 and P max were significantly higher for the trunk extensor than for the flexor one ( p , 0.05), with no statistical difference for V 0 . These results are in accordance with those previously found in the literature (Ripamonti et al 2011). They can be explained by (i) the muscle atrophy and fatty involution observed in subjects with CLBP before rehabilitation programme (Revel 1995) and (ii) the inability for these patients to mobilise muscles and to use lumbopelvic articulation (mobility and proprioception) during trunk flexion and extension comparing to healthy subjects (Mayer et al 1994).…”

“…Many studies have focused on quantifying trunk muscle quality in CLBP (Mayer et al 1994). Thus, the force -velocity and powervelocity relationships give us an interesting overview about each individual muscle properties (Ripamonti et al 2011), in particular for trunk and lower limbs.…”

Peak torque substantially varies between patients with non-specific low back pain; belong to directional preference classification, and healthy individuals—clinical biokinesiologic perspectives

“…The load varies according to the velocity used during isokinetic testing. Ripamonti et al 23) demonstrated the importance of torque-velocity relationship during any rehabilitation program. Researchers had their measurements on a group of low back pain patients.…”

Interest of isokinetic force–velocity relationships during low back pain evaluation

“…For each selected velocity, only the trial presenting the highest peak torque was considered for the data analysis. Maximal isometric torque (T 0 ), maximal velocity (V 0 ) and maximal power (P max ) were then extrapolated from the torquevelocity and power-velocity relationships (Ripamonti et al 2011). …”

“…However, isokinetic device was not commonly used neither for evaluating low back patient nor for rehabilitation training. A previous study (Ripamonti et al 2011), focusing on torque -velocity and power-velocity relationships determination, showed the interest of determining muscular parameters, such as maximal isometric torque and maximal power, from isokinetic measurements. The purpose of this study was to assess the therapy exercise programme of low back pain patient of the centre de l'Arche.…”