title: Effects of body mechanics training on performance of repetitive lifting.
abstract: OBJECTIVE
  To measure the efficacy of body mechanics instruction (BMI) in patients with low back pain.
  
  
  METHODS
  The effect of BMI was measured in four participants with back injuries using a standardized lifting protocol. Static strength, weight lifted, number of lifts completed, and motion analysis data to describe the body mechanics were measured before and after work hardening to evaluate treatment effects. The participants' performances were compared with 52 controls from an earlier study.
  
  
  RESULTS
  Starting postures, characterized by degrees of hip and knee flexion, varied by participant but favored a squat lift in three participants when compared with the controls. Dynamic motion synchrony of the hip and knee joints was similar to controls in three of the four participants. Posttest data revealed significant changes in static strength, dynamic endurance, and lifting speed.
  
  
  CONCLUSIONS
  Intensive instruction in body mechanics provided during the work-hardening treatment produced major changes in lifting styles, in terms of both starting postures and dynamic aspects of repetitive lifting. The computerized measurement procedures used in this study permitted more careful and detailed analyses of body mechanics, particularly dynamic aspects, than is possible with observational methods. This study demonstrated some of the inherent intricacies in isodynamic lifting and suggests additional areas of performance that may be important to address in BMI.
authors.affiliation: Department of Anesthesiology/CCM, University of Pittsburgh, Pennsylvania 15213, USA. liebersj@peti.sm.upmc.edu
authors.forename: S J
authors.initials: SJ
authors.lastname: Lieber
authors.forename: T E
authors.initials: TE
authors.lastname: Rudy
authors.forename: J R
authors.initials: JR
authors.lastname: Boston
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D009788:Occupational Therapy / Q000379:methods; D013122:Spinal Diseases / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation; D016896:Treatment Outcome; D014891:Weight Lifting / Q000502:physiology