Author:

Keywords:

Chronic low back pain, DYNAMOMETER, ENDURANCE, EPIDEMIOLOGY, EXTENSOR, Isokinetic dynamometer, Life Sciences & Biomedicine, Muscle strength, MUSCLE STRENGTH, Rehabilitation, Reliability, REPRODUCIBILITY, Science & Technology, Sport Sciences, TEST-RETEST RELIABILITY, TORQUE, VALIDITY, Adult, Chronic Disease, Female, Humans, Isometric Contraction, Low Back Pain, Lumbosacral Region, Male, Middle Aged, Muscle Strength, Muscle Strength Dynamometer, Muscle, Skeletal, Range of Motion, Articular, Reproducibility of Results, Torso, 1103 Clinical Sciences, 1106 Human Movement and Sports Sciences, 4201 Allied health and rehabilitation science, 4207 Sports science and exercise

Abstract:

OBJECTIVES: to assess intra/inter-operator reliability and agreement of maximum isometric abdominal and back muscle strength in a functional trunk and isolated lumbar protocol, using an isokinetic dynamometer, in healthy persons and persons with chronic nonspecific low back pain (CNSLBP). DESIGN: Test-retest. SETTING: Participants performed two assessments consisting of two protocols on the Biodex 3 system, evaluating maximum isometric back and abdominal strength in a functional trunk and isolated lumbar position. During the first assessment, each protocol was executed twice, supported by different operators. PARTICIPANTS: Healthy persons (n = 20) and persons with CNSLBP (n = 20). MAIN OUTCOME MEASURES: Intraclass Correlation (ICC), Standard Error of Measurement (SEM and %SEM), and Minimal Detectable Change (MDC) of muscle strength outcomes and seat positioning characteristics were calculated. RESULTS: Intra/inter reliability of muscle strength outcomes was excellent (ICC: 0.94-0.98), while seat positioning characteristics varied from low to high (ICC: 0-0.94). For muscle strength outcomes, %SEM ranged from 4.7 to 9.2% and MDC ranged from 14.3 to 29.8 Nm in trunk flexion and 39.1-68.5 Nm in trunk extension. CONCLUSIONS: The Biodex 3 system can be used reliably to assess maximum isometric trunk muscle strength with the aforementioned protocols in healthy persons and persons with CNSLBP. All muscle strength outcomes showed comparable agreement (%SEM < 10%).