Effect of bench height on sit-to-stand in children without disabilities and children with cerebral palsy.

OBJECTIVE To evaluate the effect of seat height on sit-to-stand (STS) in children with cerebral palsy (CP) and in children without disabilities. DESIGN A mixed design (subject type by seat height) with repeated measures for seat height. SETTING Motion analysis laboratory. PARTICIPANTS Ten children with mild CP (mean age, 10.9+/-2.7 y) and 10 children without disabilities (mean age, 8.7+/-2.4 y). INTERVENTIONS Kinematic and force measurements of STS were completed with 6 infrared cameras and 2 forceplates. MAIN OUTCOME MEASURES Phase duration of the STS movement, amplitude and timing of ground reaction forces, and maximum head velocity during the movement. RESULTS Children with CP took significantly longer to rise to standing (1.71 s) than children without disabilities (1.24 s) (F(1,18)=16.97). The extension phase of STS was also significantly longer for children with CP (.85 s) than for children without disabilities (.45 s) (F(1,18)=18.73). Seat height did not affect time to stand for either children with CP or children without disabilities (F(1,18)=2.82, P>.05). The duration of the extension phase, maximum horizontal and vertical velocity of the head, and maximum vertical ground reaction force were all significantly greater when children stood from the low bench height than from the higher bench height, although we found no significant differences by subject type for maximum horizontal and vertical head velocity or for maximum vertical ground reaction force. CONCLUSIONS Although children with CP were able to modify their motor programs for STS to accommodate changes in seat height as readily as nondisabled children, the speed with which they extended against gravity was slower; therefore, the total STS movement took longer for them to complete than for children without disabilities. Because the time to complete STS from the low and high bench did not differ, it would appear that time to ascend from sitting may be invariant and therefore be a motor control parameter for the STS movement.

[1]  M W Rogers,et al.  Speed variation and resultant joint torques during sit-to-stand. , 1991, Archives of physical medicine and rehabilitation.

[2]  M. Y. Lee,et al.  The sit-to-stand movement in stroke patients and its correlation with falling. , 1998, Archives of physical medicine and rehabilitation.

[3]  H. Hirschfeld,et al.  Coordinated ground forces exerted by buttocks and feet are adequately programmed for weight transfer during sit-to-stand. , 1999, Journal of neurophysiology.

[4]  P. Raina,et al.  Validation of a model of gross motor function for children with cerebral palsy. , 2000, Physical therapy.

[5]  P. Crenna,et al.  A motor programme for the initiation of forward‐oriented movements in humans. , 1991, The Journal of physiology.

[6]  W. A. Hodge,et al.  Influence of age on dynamics of rising from a chair. , 1991, Physical therapy.

[7]  A. Schultz,et al.  Rising from a chair: effects of age and functional ability on performance biomechanics. , 1991, Journal of gerontology.

[8]  Wim G. M. Janssen,et al.  Determinants of the sit-to-stand movement: a review. , 2002, Physical therapy.

[9]  J. Munton,et al.  Use of electromyography to study leg muscle activity in patients with arthritis and in normal subjects during rising from a chair. , 1984, Annals of the rheumatic diseases.

[10]  R.B. Davis,et al.  Clinical gait analysis , 1988, IEEE Engineering in Medicine and Biology Magazine.

[11]  Shepherd Rb,et al.  Some biomechanical consequences of varying foot placement in sit-to-stand in young women. , 1996 .

[12]  R Adams,et al.  Inter-segmental co-ordination in sit-to-stand: an age cross-sectional study. , 1999, Physiotherapy research international : the journal for researchers and clinicians in physical therapy.

[13]  Jake K. Aggarwal,et al.  Human Motion Analysis: A Review , 1999, Comput. Vis. Image Underst..

[14]  Robertw . Mann,et al.  Whole-body movements during rising to standing from sitting. , 1990, Physical therapy.

[15]  P. Grimaud.  [Cerebral palsy]. , 1972, Pediatrie.

[16]  K. Song,et al.  Ankle-foot orthoses for preambulatory children with spastic diplegia. , 1997, Journal of pediatric orthopedics.

[17]  J. Perry,et al.  Rising from a chair. Influence of age and chair design. , 1985, Physical therapy.

[18]  J. Bonar.  Physical Therapy for Children , 1995 .

[19]  Y. Pai,et al.  Control of body mass transfer as a function of speed of ascent in sit-to-stand. , 1990, Medicine and science in sports and exercise.

[20]  R. Soames,et al.  The influence of initial posture on the sit-to-stand movement , 2004, European Journal of Applied Physiology and Occupational Physiology.

[21]  R. Palisano,et al.  Development and reliability of a system to classify gross motor function in children with cerebral palsy , 1997, Developmental medicine and child neurology.

[22]  Y. Pai,et al.  Segmental contributions to total body momentum in sit-to-stand. , 1991, Medicine and science in sports and exercise.

[23]  D. V. Vander Linden,et al.  Variant and invariant characteristics of the sit-to-stand task in healthy elderly adults. , 1994, Archives of Physical Medicine and Rehabilitation.

[24]  Robertw . Mann,et al.  Mechanics of a constrained chair-rise. , 1991, Journal of biomechanics.

[25]  P. Riley,et al.  Sit to stand from progressively lower seat heights -- alterations in angular velocity. , 1996, Clinical biomechanics.

[26]  T. Andriacchi,et al.  The influence of chair height on lower limb mechanics during rising , 1989, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.