Validity and Reliability of L Test in Persons With Multiple Sclerosis

General Information about the Research, Rationale and Objectives:

Multiple Sclerosis (MS), a chronic inflammatory disease of the central nervous system, is a disease characterized by myelin, oligodendrocyte and axon damage [1]. Research continues on the autoimmune, infectious, environmental, vascular and genetic origins of this disease, which affects approximately 2.5 million people in the world and is seen 2-3 times more in women than in men [1, 2]. Although the signs and symptoms of the disease vary according to the location of the lesion; Loss of balance and strength, spasticity, sensory disturbances, fatigue, ataxia, autonomic dysfunction, and decreased visual acuity are frequently observed [1].

Abnormalities and losses in balance management are frequently seen in individuals with MS [3-6] . This abnormality, together with other risk factors, increases the risk of falling [7] and causes limitations in patients' activities of daily living. Studies on balance problems in elderly individuals are frequently investigated in the literature. However, the frequency of falls in this population was found to be 1.5 falls per year [8], while another study investigating individuals with MS found an average of 9 falls per year [7]. In order to develop fall prevention or reduction strategies, it is necessary to evaluate different aspects of motor impairment and to accurately identify factors contributing to falls [9-11]. Since falls among MS patients have a multifactorial etiology, multiple evaluations are necessary to explore the balance problem.

Although various scales have been developed to evaluate the functional level of MS patients [12, 13], the use of frequently applied scales in this patient group allows the results to be compared with other studies and other pathologies. In addition, the use of frequently applied scales does not require special training of raters. Previous studies have used the Berg Balance Scale, the Functional Reach Test, the Timed Get Up and Walk test, and general measures of fall risk (eg, questioning the date of fall) [14-16]. These tests primarily assess the ability to walk forward, turn back, and take a step.

The reliability of the TUG in people with MS has ranged from 'good' to 'excellent' [17,18], but the TUG is only an opportunity for unilateral disorders to turn in a preferred direction [19]. Thus, despite good reliability and validity, TUG currently has limitations in MS that can only be overcome by adding complex and potentially excessively expensive instrumentation. The L test is a modification of the TUG that extends the walking distance from 6 to 20 m and also requires participants to make both clockwise and counterclockwise turns. Therefore, it may have limited sensitivity and the potential to overcome ceiling effects. The L test was originally designed for individuals following lower limb amputation and has since been evaluated in stroke and hospitalized elderly subjects [19-21]. In all three studies, the L test showed good reliability and also showed good correlation with the TUG. The aim of this study is to evaluate the L test in terms of test/retest reliability and concurrent validity with TUG in individuals with MS. There are no studies in the literature investigating the validity and reliability of this test in individuals with MS. Reliability is population specific and it is important to investigate the reliability of the L test in MS patients. Therefore, the aim of our study is to reveal the test-retest reliability and validity of the L test.