Dynamic pressure measurement

The study was designed as a controlled, same-subject study that measured the force generated by each user during propulsion in three different one-arm drive wheelchairs.

The data being measured were vertical reaction forces at the buttock/seat interface in Newtons. These were measured using the CONFORMat® Pressure Measurement System, a portable interface pressure mapping system, which records pressure distribution under the contact area. The system includes pressure-sensing hardware and software.

The study was designed to compare the measurements taken in each wheelchair for each individual participant, with each user acting as their own control. This was considered to be an appropriate approach due to the heterogeneity of hemiplegia within the user group and the bespoke postural and pressure equipment that they used in the wheelchairs during the study.

Project aims

The aim of this pilot study was to compare the vertical reaction forces  generated in three different Action 3 manual one-arm drive wheelchairs:

  • dual handrim,
  • a lever drive
  • a Neater Uni-wheelchair (NUW)

A CONFORmat® Pressure measurement mat, placed on top of the users’ prescribed cushion, measured vertical force at the buttock/seat interface on both hemiplegic and non-hemiplegic sides in each wheelchair.

Fifteen hemiplegic users were randomly assigned each wheelchair to drive around an indoor obstacle course. During propulsion of a multiple sensor, continuous measurement of force was recorded. Time taken to complete the circuit was recorded. Mean force and confidence intervals for each buttock were calculated per user per wheelchair.

Project impact

The dual handrim produced the highest vertical force during propulsion under the right buttock and the lever drive produced the least force. The NUW completed the course quickest.

The conclusions were that the dual-handrim wheelchair requires the greatest vertical force during propulsion. Since increases in this seat vertical reaction force may be related to the propulsive force. Further investigation is indicated as this may be a significant factor for clinicians when prescribing one-arm drive wheelchairs.

Research team

Anne Mandy

Lucy Redhead

Carol McCudden, Wheelchair Services, Betsi Cadwaladr University Local Health Board, Wrexham, UK

Jon Michaelis, Neater Solutions, Buxton, UK

Output

Research article

Partners

Carol McCudden, Wheelchair Services, Betsi Cadwaladr University Local Health Board, Wrexham, UK

Jon Michaelis, Neater Solutions, Buxton, UK