title: Comparison of the kinetic characteristics of standing and sitting Tai Chi forms.
abstract: OBJECTIVE
  To compare the kinetic characteristics of Tai Chi forms performed in standing and seated positions.
  
  
  METHODS
  An experienced Tai Chi master was invited to perform the Tai Chi Qi Qong 18-form while standing and seated. Two force platforms were used to track the centre of pressure (COP) during the Tai Chi movements. Centre of mass (COM) displacement was measured using a video motion analysis system.
  
  
  RESULTS
  In standing, the maximum COP displacements in the anteroposterior and mediolateral directions ranged from 2.6% to 9.5%, and 0.3% to 29.6% of the subject's height, respectively. The maximum COP displacements in sitting were smaller, with mean displacements of 0.7% and 0.1% of height in the anteroposterior and ML directions, respectively. The subject's COM moved in the vertical direction in slow, coordinated and smooth patterns.
  
  
  CONCLUSIONS
  The kinetic data on each of the 18 Tai Chi forms studied can guide the choice of suitable Tai Chi forms for balance training. Sitting Tai Chi is recommended for rehabilitating the balance of frail older adults who have difficulty standing. Because of the minimal demands of sitting Tai Chi for balance control, progressing to practice in standing as quickly as possible is recommended.
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Eric S F
authors.initials: ES
authors.lastname: Leung
authors.forename: William W N
authors.initials: WW
authors.lastname: Tsang
mesh_terms: D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008875:Middle Aged; D004856:Postural Balance; D026302:Tai Ji; D013647:Task Performance and Analysis