Effect of static and dynamic back extensor muscles endurance exercise on pain intensity, activity limitation and participation restriction in patients with long-term mechanical low-back pain

Introduction: Long-Term Mechanical Low-Back Pain (LMLBP) constitutes a serious challenge to clinicians and researchers. This study evaluated the effect of static and dynamic back extensor muscles endurance exercise on pain intensity, activity limitation and participation restriction in patients with LMLBP treated with the McKenzie Protocol (MP). Materials and Methods: Eighty four patients with LMLBP participated in this single-blind controlled trial. The participants were assigned to one of three groups; the MP Group (MPG), MP plus Static Back Endurance Exercise Group (MPSBEEG) and MP plus Dynamic Endurance Exercise Group (MPDBEEG) using permuted randomized block. Treatment was applied thrice weekly for 8 weeks and outcomes were measured in terms of pain intensity, activity limitation and participation restriction at the end of 4th and 8th week of study using Quadriple Visual Analogue Scale (QVAS), Roland – Morris Back Pain Questionnaire (RMBPQ), and Oswestry Low-back Disability Questionnaire (OLBDQ). Data were analyzed using descriptive and inferential statistics at 0.05 alpha level. Results: Sixty seven participants whose ages ranged between 38 and 62 years completed the study comprising of 25, 22 and 20 in MPG, MPSBEEG and MPDBEEG respectively. The groups were comparable in age, physical characteristics and baseline outcome measures (p>0,05). Within-group comparison across the three time-points of the study revealed that the different treatment regimens had significant effects on all the outcome measures (p<0,05). There were no significant differences in the mean change scores on QVAS (p=0,579) and OLBDQ (p=0,755) at across the groups at week 4 and 8 respectively. Post-hoc analysis showed that MPDEEG had higher mean change in RMBPQ (p=0,001) at week 4 only. Conclusion: McKenzie protocol as well as the addition of static or dynamic back extensors endurance exercises are effective in reducing pain and disability in patients with long-term mechanical low-back pain. However, four weeks of McKenzie protocol plus dynamic back extensors endurance exercise resulted in better decrease in participation restriction. Slowa kluczowe cwiczenie, statyczne, dynamiczne, metoda McKenzie, przewlekly bol krzyza, aktywnośc, partycypacja Streszczenie Wstep: Przewlekly bol ledźwiowy o podlozu mechanicznym (ang. Long-Term Mechanical Low-Back Pain – LMLBP) stanowi powazne wyzwanie dla lekarzy i badaczy. Niniejsze badanie ocenilo wplyw statycznych i dynamicznych wytrzymalościowych cwiczen prostownika grzbietu na natezenie bolu, ograniczenie aktywności i partycypacji u chorych z LMLBP leczonych metodą Mc Kenzie (ang. Mc Kenzie Protocol – MP). Materialy i metody: 84 chorych z LMLBP uczestniczylo w kontrolowanym badaniu przeprowadzonym metodą pojedynczej ślepej proby. Metodą randomizacji blokowej chorych przydzielono do jednej z trzech grup: Grupa MP (ang. Mc Kenzie Protocol Group – MPG), grupa MP plus statyczne cwiczenia wytrzymalościowe prostownika grzbietu (ang. Mc Kenzie Protocol Static Back Endurance Exer-