title: Reliability and Validity of Standing Back Extension Test for Detecting Motor Control Impairment in Subjects with Low Back Pain.
abstract: BACKGROUND
  Low back pain is a chronic health problem with high socioeconomic impact. Specific diagnosis or treatment approach has not yet effectively established to treat chronic low back pain. Standing Back Extension Test is one of the clinical measures to detect the passive extension subgroup of Motor Control Impairment (MCI); which could have an impact on spinal stability leading to recurrent chronic low back pain. Reliability and validity of this test is not fully established.
  
  
  OBJECTIVE
  To determine the intra-rater and inter-rater reliability and concurrent validity of the Standing Back Extension Test for detecting MCI of the lumbar spine.
  
  
  METHODS
  A total of 50 subjects were included in the study, 25 patients with Non Specific Low Back Pain (NSLBP) (12 men, 13 women) and 25 healthy controls (12 men, 13 women) were recruited into the study. All subjects performed the test movement. Two raters blinded to the subjects rated the test performance as either 'Positive' or 'Negative' based on the predetermined rating protocol. The thickness of Transverse Abdominis (TrA) muscle was assessed using Rehabilitative Ultrasound Imaging (RUSI).
  For reliability, the kappa coefficient with percent agreement was calculated and for assessing the validity Receiver Operator Characteristic (ROC) curves and Area under the Curve (AUC) were constructed.
  
  
  RESULTS
  The standing back extension test showed very good intra-rater (k=0.87 with an agreement of 96%) and good inter-rater (k=0.78 with an agreement of 94%) reliability and high AUC for TrA muscle.
  
  
  CONCLUSIONS
  The standing back extension test was found to be a reliable and a valid measure to detect passive extension subgroup for MCI in subjects with low back pain.
authors.affiliation: Junior Executive, Department of Physiotherapy, Breach Candy Hospital Trust , Mumbai, India .
authors.forename: Gauri A
authors.initials: GA
authors.lastname: Gondhalekar
authors.affiliation: Professor, Maharishi Markandeshwar Institute of Physiotherapy and Rehabilitation (MMIPR), Maharishi Markandeshwar University (MMU) , Mullana-Ambala, Haryana, India .
authors.forename: Senthil P
authors.initials: SP
authors.lastname: Kumar
authors.affiliation: Associate Professor Department of Physiotherapy, Kasturba Medical College, Manipal University, KMC Hospital , Attavara, Mangalore, Karnataka, India .
authors.forename: Charu
authors.initials: C
authors.lastname: Eapen
authors.affiliation: Professor and Head, Department of Radio-diagnosis and Imaging, Kasturba Medical College, Mangalore and KMC Hospitals , Mangalore, Karnataka, India .
authors.forename: Ajit
authors.initials: A
authors.lastname: Mahale
keywords: Movement impairment; Non specific low back pain; Relative flexibility