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Sliding and lower limb mechanics during sit-stand-sit transitions with a standing wheelchair.

Yang YS, Chen MD, Fang WC, Chang JJ, Kuo CC - Biomed Res Int (2014)

Bottom Line: The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight.A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions.Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

View Article: PubMed Central - PubMed

Affiliation: Department of Occupational Therapy, College of Health Science, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan.

ABSTRACT

Purpose: This study aimed to investigate the shear displacement between the body and backrest/seat, range of motion (ROM), and force acting on the lower limb joints during sit-stand-sit transitions by operating an electric-powered standing wheelchair.

Methods and materials: The amounts of sliding along the backrest and the seat plane, ROM of lower limb joints, and force acting on the knee/foot were measured in twenty-four people with paraplegia.

Results: Without an antishear mechanism, the shear displacement was approximately 9 cm between the user's body and the backrest/seat surfaces. During standing up, the user's back slid down and the thigh was displaced rearward, but they moved in opposite directions when wheelchair sat back down. A minimum of 60 degrees of ROM at the hip and knee was needed during sit-stand-sit transitions. The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight.

Conclusion: Sliding between the body and backrest/seat occurred while transitioning from sitting to standing and vice versa. A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions. Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

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Related in: MedlinePlus

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fig1: Experimental setting.

Mentions: An electrically powered standing wheelchair (Model LY-ESB240, Comfort Orthopedic Co. Ltd., Chia-Yi, Taiwan) was used in this study. The overall dimension of length with footrests, seat height, and width were 113.5 cm, 56 cm, and 45.7 cm, respectively. The maximal angle to hoist a user upright was 80 degrees. No particular shear reduction technology either by back or seat frames was employed in this model. Each participant was required to wear tight fitting clothing (e.g., spandex shorts and sleeveless shirt) to prevent problems with “marker plucking.” Reflective markers were placed bilaterally to the surface of the skin over the following bony landmarks: acromion process, great trochanter, lateral epicondyle of the femur, the medial and lateral malleoli, and the fifth metatarsal base. Moreover, eight additional markers were placed on both sides of the backrest frame and seat frame of the wheelchair to determine the backrest and seat reference plane. Three-dimensional marker trajectory data were measured using a six-camera motion analysis system (Qualisys Medical AB, Göteborg, Sweden) at a sampling rate of 120 Hz (Figure 1).


Sliding and lower limb mechanics during sit-stand-sit transitions with a standing wheelchair.

Yang YS, Chen MD, Fang WC, Chang JJ, Kuo CC - Biomed Res Int (2014)

Experimental setting.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109664&req=5

fig1: Experimental setting.
Mentions: An electrically powered standing wheelchair (Model LY-ESB240, Comfort Orthopedic Co. Ltd., Chia-Yi, Taiwan) was used in this study. The overall dimension of length with footrests, seat height, and width were 113.5 cm, 56 cm, and 45.7 cm, respectively. The maximal angle to hoist a user upright was 80 degrees. No particular shear reduction technology either by back or seat frames was employed in this model. Each participant was required to wear tight fitting clothing (e.g., spandex shorts and sleeveless shirt) to prevent problems with “marker plucking.” Reflective markers were placed bilaterally to the surface of the skin over the following bony landmarks: acromion process, great trochanter, lateral epicondyle of the femur, the medial and lateral malleoli, and the fifth metatarsal base. Moreover, eight additional markers were placed on both sides of the backrest frame and seat frame of the wheelchair to determine the backrest and seat reference plane. Three-dimensional marker trajectory data were measured using a six-camera motion analysis system (Qualisys Medical AB, Göteborg, Sweden) at a sampling rate of 120 Hz (Figure 1).

Bottom Line: The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight.A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions.Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

View Article: PubMed Central - PubMed

Affiliation: Department of Occupational Therapy, College of Health Science, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan.

ABSTRACT

Purpose: This study aimed to investigate the shear displacement between the body and backrest/seat, range of motion (ROM), and force acting on the lower limb joints during sit-stand-sit transitions by operating an electric-powered standing wheelchair.

Methods and materials: The amounts of sliding along the backrest and the seat plane, ROM of lower limb joints, and force acting on the knee/foot were measured in twenty-four people with paraplegia.

Results: Without an antishear mechanism, the shear displacement was approximately 9 cm between the user's body and the backrest/seat surfaces. During standing up, the user's back slid down and the thigh was displaced rearward, but they moved in opposite directions when wheelchair sat back down. A minimum of 60 degrees of ROM at the hip and knee was needed during sit-stand-sit transitions. The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight.

Conclusion: Sliding between the body and backrest/seat occurred while transitioning from sitting to standing and vice versa. A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions. Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

Show MeSH
Related in: MedlinePlus