Joint Bone Spine 78 (2011) 291–297 Original article Evaluation of the posture and muscular strength of the trunk and inferior members of patients with chronic lumbar pain Abdelmoneem Yahia a,d , Salma Jribi a,d , Sameh Ghroubi a,d , Mohamed Elleuch b,d , Sofiène Baklouti c,d , Mohamed Habib Elleuch a,∗,d a Department of Physical Medicine and Functional Rehabilitation, university of the South, Habib Bourguiba University Hospital, El Ain Road, 3029 Sfax, Tunisia b Department of Rheumatology, Rabta Hospital, Jbel Lakhdhar Street, 1007 Tunis, Tunisia c Department of Rheumatology, Hedi Chaker Hospital, El Ain Road, 3029 Sfax, Tunisia d The Research Unit of the assessment of musculoskeletal disorders, University of the South, 04/UR/08-07, 3000 Sfax, Tunisia article info Article history: Accepted 3 August 2010 Available online 23 October 2010 Keywords: Chronic lumbar Muscular forces Posture Isokinetic Evaluation abstract Objective: We examine the postural profile and muscular forces of the trunk and inferior members of patients with chronic low back pain. Methods: In this study, we include 60 subjects forming two groups: a first group (G1) of 30 patients with chronic low back pain and a second group (G2) of 30 healthy subjects. Every subject profited from an isokinetic evaluation of the muscular forces of the trunk (at 60 and 90 ◦ .s -1 ) and knees (at 60 and 120 ◦ .s -1 ) and of a postural evaluation. The isokinetic evaluation was carried out using Cybex ® Norm II dynamometer with its Trunk Extension/Flexion (TEF) module set in concentric mode. The parameter under study was the torque peak. The postural evaluation was accomplished using the platform SATEL for the balance analysis associated with four conditions: static on stable plan open eyes (OE) then closed eyes (CE) and static on unstable plan OE then CE. The parameters under study were the averages of the total lengths, total surfaces, and the X and Y means. Results: The averages of the torque peaks of the trunk flexor and extensor muscles at the speeds of 60 and 90 ◦ .s -1 were inferior in group G1 as compared to G2. The differences were statistically insignifi- cant only for the extensor muscles (p < 0.005). The averages of the torque peaks of the knee flexors and extensors at 60 and 120 ◦ .s -1 were the lowest in group G1. The differences were significant (p < 0.05). The averages of postural parameters were more important in group G1, indicating a postural deficit in this group. Conclusion: We showed deficits of the posture and muscles of the trunk and knees of patients with chronic lumbar pain. The muscular deficit of the trunk predominates on extensors. © 2010 Société franc ¸ aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved. 1. Introduction The low back pain (LBP) is a real public health problem and a common reason for consultation. The importance of the social costs attributed to LBP is largely due to the chronic form of the disease, which accounts for only 5–10% of the cases [1]. Chronic low back pain (CLBP) is characterized by both physical and psychological deconditioning. Its treatment by functional restoration reflects an accurate assessment of shortcomings such as lack of trunk muscles and lower limbs and impaired postural control could be observed in CLBP. ∗ Corresponding author. Tel.: +00216 74 450584; fax: +00216 74 450584. E-mail address: habib.eleuch@rns.tn (M. Habib Elleuch). Few studies have focused on evaluating the strengths of the muscles of the lower limbs [2,3], as well as postural control [4,5] in the CLBP. The objective of our study is to confirm the deficits of the posture and muscles of the trunk and lower limbs of patients with CLBP and to discuss possible explanations for this deficit in order to choose adequate treatment in rehabilitation. 2. Methods This is a case-control study, conducted from January to July 2009, in the Physical Medicine and Functional Rehabilitation ward, in Habib Bourguiba University Hospital in Sfax, Tunisia, on 60 people which were divided into two groups: the first group (G1) contains CLBP patients and the second one (G2) healthy people. 1297-319X/$ – see front matter © 2010 Société franc ¸ aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2010.09.008