Showing papers by "Mohamad Parnianpour published in 2007"

Translation and validation study of the Iranian versions of the Neck Disability Index and the Neck Pain and Disability Scale.

Abstract: STUDY DESIGN Cultural translation and psychometric testing OBJECTIVE To translate and validate the Iranian versions of the Neck Disability Index (NDI-IR) and the Neck Pain and Disability Scale (NPDS-IR) SUMMARY OF BACKGROUND DATA The widely used the NDI and the NPDS scales have not been translated and validated for Persian-speaking patients with neck pain This was to provide a validated instrument to measure functional status in patients with neck pain in Iran METHODS The translation and cultural adaptation of the original questionnaires were carried out in accordance with the published guidelines One hundred and eighty-five patients with neck pain were participated in the study Patients were asked to complete a questionnaire booklet including the NDI-IR, the NPDS-IR, the Iranian SF-36, and a visual analog scale (VAS) of pain To carry out the test-retest reliability, 30 randomly selected patients with neck pain were asked to complete the questionnaire booklet 48 hours later for the second time RESULTS Cronbach I± coefficient for the NDI-IR was 088 and for the 4 subscales of the NPDS-IR was found to be satisfactory (ranging from 074 to 094) The NDI-IR and the NPDS-IR subscales showed excellent test-retest reliability (intraclass correlation coefficient ranged from 090 to 097; P < 001) The correlation between the NDI-IR and the NPDS-IR subscales and functional scales of the SF-36 showed desirable results, indicating a good convergent validity (Pearson correlation coefficients ranged from -031 to -070) The correlation between the NDI-IR and the VAS was 071 and between the NPDS-IR subscales and the VAS ranged from 063 to 079 (P < 001) CONCLUSION The Iranian versions of the NDI and NPDS are reliable and valid instruments to measure functional status in Persian-speaking patients with neck pain in Iran They are simple and easy to use and now can be applied in clinical settings and future outcome studies in Iran and other Persian speaking communities © 2007 Lippincott Williams & Wilkins, Inc

Pregnancy related pelvic girdle pain and low back pain in an Iranian population.

Abstract: Study design A cross-sectional study in pregnancy. Objectives To differentiate between pregnancy related pelvic girdle pain (PGP) and low back pain (LBP) in Iranian women, and investigate the prevalence of each syndrome. Summary of background data Most of the information about PGP and LBP has been obtained in Western countries. There are few studies to investigate pregnancy related lumbopelvic pain, and, especially, differentiate between PGP and LBP in non-Western countries, particularly in the Middle East. Methods This study included 325 pregnant women, ranging in age from 16 to 42 years. All pregnant women were interviewed using a questionnaire. Two trained physical therapists performed the posterior pelvic pain provocation test on all women with lumbopelvic pain. Results A total of 161 pregnant women (49.5%) had reported lumbopelvic pain at the time of the examination. Based on the posterior pelvic pain provocation test, 91 women (28%) had PGP, 43 (13.2%) had LBP, and 27 (8.3%) had both PGP and LBP simultaneously. The intensity of pain in women with lumbopelvic pain using the visual analog scale was 5.6 (standard deviation 2.0; range 2-10). Conclusions About 1 in every 2 pregnant women studied experienced lumbopelvic pain at the time of the examination. In this study, PGP was almost 2 times more common than LBP. The high prevalence of PGP suggests that this symptom is a significant health problem in Iranian pregnant women, and needs more attention by Iranian health professionals and researchers.

Trunk biomechanical models based on equilibrium at a single-level violate equilibrium at other levels

Abstract: Accurate estimation of muscle forces in various occupational tasks is critical for a reliable evaluation of spinal loads and subsequent assessment of risk of injury and management of back disorders. The majority of biomechanical models of multi-segmental spine estimate muscle forces and spinal loads based on the balance of net moments at a single level with no consideration for the equilibrium at remaining levels. This work aimed to quantify the extent of equilibrium violation and alterations in estimations when such models are performed at different levels. Results are compared with those of kinematics-driven model that satisfies equilibrium at all levels and EMG data. Regardless of the method used (optimization or EMG-assisted), single-level free body diagram models yielded estimations that substantially altered depending on the level considered (i.e., level dependency). Equilibrium of net moment was also grossly violated at remaining levels with the error increasing in more demanding tasks. These models may, however, be used to estimate spinal compression forces.

Dynamic iso-resistive trunk extension simulation: Contributions of the intrinsic and reflexive mechanisms to spinal stability

Abstract: The effects of external resistance on the recruitment of trunk muscles and the role of intrinsic and reflexive mechanisms to ensure the spinal stability are significant issues in spinal biomechanics. A computational model of spine under the control of 48 anatomically oriented muscle actions was used to simulate iso-resistive trunk movements. Neural excitation of muscles was attained based on inverse dynamics approach along with the stability-based optimization. The effect of muscle spindle reflex response on the trunk movement stability was evaluated upon the application of a perturbation moment. In this study, the trunk extension movement at various resistance levels while extending from 60° flexion to the upright posture was investigated. Incorporation of the stability condition as an additional constraint in the optimization algorithm increased antagonistic activities for all resistance levels demonstrating that the co-activation caused an increase in the intrinsic stiffness of the spine and its stability in a feed-forward manner. During the acceleration phase of the movement, extensors activity increased while flexors activity decreased in response to the higher resistance. The co-activation ratio noticed in the braking phase of the movement increased with higher resistance. In presence of a 30 Nm flexion perturbation moment, reflexive feed-back noticeably decreased the induced deviation of the velocity and position profiles from the desired ones at all resistance levels. The stability-generated co-activation decreased the reflexive response of muscle spindles to the perturbation demonstrating that both intrinsic and reflexive mechanisms contribute to the trunk stability. The rise in muscle co-activation can ameliorate the corruption of afferent neural sensory system at the expense of higher loading of the spine.