The main dimensions of an electric wheelchair include seat height, width, depth, seat inclination, backrest height and inclination, armrest height, and pedal height. So what is the determination of the basic size parameters of the electric wheelchair? Let's take a look at it next.

   This is the content list:

•    Seat height, width, and depth

•    Seat inclination

•    Backrest height, width, and inclination

•    Armrest height and spacing
  

  
  

  Seat height, width, and depth

   Seat height refers to the distance from the upper support surface of the seat cushion to the contact point between the wheel and the ground. The height of the seat surface is related to the stability of the power wheelchair during driving. Too high seat surface will cause the center of gravity of the wheelchair vehicle to rise, thus reducing the stability of the wheelchair vehicle, and it is easy to cause the wheelchair to lean back, roll over, and forward during the driving process. A reasonable seat height should ensure that the user's thigh muscles are not compressed, while the calf can be placed on the footrest naturally and both legs can freely complete forward extension and backward flexion. At the 95th percentile, the calf in the sitting position of the female is increased by about 500mm to the height of the foot.

   The width of the seat is determined by the hip width of the sitting position and the elbow width of the sitting position. The electric wheelchair seat is too wide, causing the user's elbows to stretch out on both sides, causing shoulder fatigue and reducing sitting stability; It will squeeze the human body and affect the comfort of the wheelchair. And considering the functional correction and psychological correction, the seat width is determined to be 445mm.

   The seat depth of a wheelchair is based on the design principle of ensuring stable sitting posture and effective support of the lumbar spine, leaving a certain gap between the back of the calf and the front surface of the seat. The seat depth is too short, the load on the buttock muscles will be too concentrated, and it is easy to cause acne: the seat depth will damage the lumbar spine. To ensure the high adaptability of the wheelchair, the design is based on the smaller percentile of the human body size, plus a certain amount of correction, and finally taken as 440 mm.

   Seat inclination

   The angle between the support surface of the electric wheelchair seat and the horizontal plane is called the seat surface inclination angle. Under normal circumstances, to prevent the user's buttocks from sliding forward when sitting for a long time and ensure sufficient support for the lower back, the seat is generally designed so that the inclination of the seat surface is too large, which will lead to abnormal bending of the lumbar spine, which will compress the abdomen and cause due to the physical injury of the user, the ideal seat surface inclination angle is generally 4°~8°.

   Backrest height, width, and inclination

   To meet the user's sitting posture adjustment needs, the backrest height-adjustable design is adopted. The height of the backrest is based on the sitting height of the human body, and in addition, it must meet the requirements of national standards, that is, the total height of the indoor and outdoor power wheelchair does not exceed 1090mm. The adjustable backrest has a minimum height of 460 mm and a maximum height of 540 mm. The width of the backrest mainly refers to the shoulder width of the human body, based on the maximum shoulder width of the 95th percentile of women, which is 438 mm, plus the correction amount, which is taken as 440 mm. The obtuse angle between the backrest and the horizontal plane is called the backrest inclination angle, which is generally 95°~120°. According to research, when the angle between the human torso and the horizontal plane is 115°, the human spine naturally stretches and is relatively comfortable. Considering the stability factor of an electric wheelchair, the inclination angle of the backrest is 105°. If the inclination angle of the seat surface is 4°, the angle between the seat surface and the backrest is 109°.

   Armrest height and spacing

   Armrest height refers to the distance from the armrest support surface to the seat support surface. The armrest mainly supports the weight of the arm, and can also maintain the stability of the body when the bumps and shakes, assisting the user to stand, get up or change the sitting position. The design of the electric wheelchair is mainly based on the elbow height in the sitting position. The 5th percentile female sitting elbow height is selected as 215mm. Considering the amount of correction, the height of the armrest is 225mm. The distance between the armrests affects the comfort of the sitting posture. The design mainly refers to the sitting posture width of the human body. Based on the 95th percentile female sitting posture elbow width of 478 mm, plus the correction amount, the armrest distance is designed to be 525 mm.

   The above is the relevant content about the determination of the basic size parameters of electric wheelchair. If you are interested in a it, you can contact us. Our website is www.jbhmedical.com.