title: Effects of Holding an External Load on the Standing Balance of Older and Younger Adults With and Without Chronic Low Back Pain.
abstract: The purpose of this study was to assess the effect of holding an external load on the standing balance of younger and older adults with and without chronic low back pain (CLBP).
  
  
  
  Twenty participants with and 20 without CLBP participated in the study. Each group contained 10 younger (50% men) and 10 older adults (50% men). Participants were instructed to look straight ahead while standing on a force platform during two 120-second trials with and without holding an external load (10% of body mass). The center of pressure area, mean velocity, and mean frequency in the anteroposterior and mediolateral directions were measured.
  
  
  
  Older adults had worse standing balance than younger adults did (P < .001, d = 0.20). There were no significant balance differences between participants with and without CLBP within age groups during standing balance condition. However, holding the external load significantly increased postural instability for both age groups and CLBP status, with mean effect size across center of pressure variables of d = 0.82 for older participants without CLBP and d = 2.65 for younger participants without CLBP. These effects for people with CLBP were d = 1.65 for subgroup of older and d = 1.60 for subgroup of younger participants.
  
  
  
  Holding an external load of 10% of body mass increased postural instability of both younger and older adults with and without CLBP.
authors.affiliation: Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Shigaki
authors.affiliation: Physical Therapy & Neuroscience Departments, Wertheims' Colleges of Nursing and Health Sciences & Medicine, Florida International University, Miami, FL.
authors.forename: Edgar Ramos
authors.initials: ER
authors.lastname: Vieira
authors.affiliation: Universidade Norte do Paraná, Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: André Wilson
authors.initials: AW
authors.lastname: de Oliveira Gil
authors.affiliation: Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: Cynthia Gobbi Alves
authors.initials: CGA
authors.lastname: Araújo
authors.affiliation: Universidade Norte do Paraná, Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: Mariana Zingari
authors.initials: MZ
authors.lastname: Carmargo
authors.affiliation: Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: Leandro Amaral
authors.initials: LA
authors.lastname: Sturion
authors.affiliation: Universidade Norte do Paraná, Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil.
authors.forename: Marcio Roǵerio
authors.initials: MR
authors.lastname: de Oliveira
authors.affiliation: Universidade Norte do Paraná, Laboratory of Functional Evaluation and Human Motor Performance (LAFUP), Londrina, Brazil. Electronic address: rubens@unopar.br.
authors.forename: Rubens A
authors.initials: RA
authors.lastname: da Silva
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology; D015992:Body Mass Index; D016022:Case-Control Studies; D059350:Chronic Pain / Q000175:diagnosis*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012016:Reference Values; D014891:Weight Lifting / Q000502:physiology; D016474:Weight-Bearing
keywords: Aging; Low Back Pain; Postural Balance