Journal of sport rehabilitation | 2019
Effect of Lower Limb Muscle Fatigue on Ground Reaction Force Components During Landing in People With Nonspecific Chronic Low Back Pain.
Abstract
CONTEXT\nThe link between landing parameters and lower limb muscle fatigue in association with chronic low back pain (CLBP) is not well understood.\n\n\nOBJECTIVE\nTo examine the effects of fatigue on the ground reaction force components during landing in people with nonspecific CLBP.\n\n\nDESIGN\nQuasi-experimental study.\n\n\nSETTING\nClinical biomechanics laboratory.\n\n\nPARTICIPANTS\nA total of 44 subjects were equally divided into a healthy group and a group with CLBP.\n\n\nMAIN OUTCOME MEASURES\nThe ground reaction force along anterior-posterior (y) and medial-lateral (x) and vertical (z) axes, time to peak (TTP), the rate of force development, and impulses for all axes were calculated. A repeated-measures analysis of variance (group\u2009×\u2009fatigue) was used to compare the data among groups.\n\n\nRESULTS\nIn the unfatigued conditions, the amplitudes of Fy3, Fz2, and TTP of Fy1, Fy2, Fz1, Fz2, Fz3, Fz4, rate of force development in Y in the CLBP subjects are significantly different than those in the healthy subjects (P\u2009<\u2009.05). In the fatigued conditions, the amplitudes of Fz2, Fz3, Fz4, and TTP of Fy2, Fy3, Fy4, Fz2, impulses of X2, Z in the CLBP group were significantly different than those in the healthy subjects (P\u2009<\u2009.05). Within-group comparisons of measured Fx1, Fy1, Fy2, Fz2, Fz4 and TTP of Fx1, Fy1, Fy2, Fz2, Fz3, Fz4, impulses of X2, z were significantly different from prefatigue to postfatigue in the healthy group (P\u2009<\u2009.05). Within-group comparisons of measured Fx1, Fy1, Fz1, Fz2 and TTP of Fx5, Fz1, impulses of X2 were significantly differed from prefatigue to postfatigue in the CLBP group (P\u2009<\u2009.05).\n\n\nCONCLUSIONS\nIt seems that TTP of ground reaction force variables in CLBP may have clinical values for rehabilitation. Muscle fatigue altered landing performance. However, patients with CLBP will respond differently to lower-extremity fatigue. These altered variables in patients with low back pain are the cause of future injuries or lower-extremity injuries that need to be addressed in further studies.