Letter to the editor

摘要

Wilemink et al1 recently published results from a prospective single-arm trial examining the effects of isolated lumbar extension (ILEX) resistance training (RT) upon lumbar multifidus (MF) cross-sectional area (CSA), and disability using the Roland-Morris disability questionnaire. Investigating the effects of exercise interventions in chronic low back pain to understand mechanisms involved in producing clinical improvements is of considerable value. This is particularly important considering recent suggestions that conditioning effects of exercise interventions (i.e., improved strength, endurance, or hypertrophy) are not associated with change in clinical outcomes.2 However, as Willemink et al1 examined a highly specific exercise, ILEX, their study could potentially provide more specific information. We have previously highlighted the importance of specificity.3 Unfortunately, the methodology of this study creates difficulty in surmising why no change in MF CSA occurred despite improved Roland-Morris disability questionnaire scores. Absence of control group notwithstanding, particular concern pertains to control of RT variables in their intervention.