The first purpose of this study is to characterize the relationship among propulsion workload, self-selected propulsion speed, and propulsion kinetics/kinematics. The second purpose is to assess the between days repeatability/reliability of the above outcomes. There are no hypothesis This is a repeated measures clinical trial. All participants will complete the following: 1) Acclimation to propelling a manual wheelchair on a wheelchair ergometer; 2) Graded exercise test on the wheelchair ergometer to 80% of age adjusted estimated maximal heart rate; and 3) N=20 one minute propulsion bouts on the wheelchair ergometer.
Participants will complete two visits in a 14 day period. Visit 1 will require 3-4 hours. Visit 2 will require 2-3 hours. During visit 1 participant will complete: 1) Acclimation to propelling a manual wheelchair on a wheelchair ergometer; 2) Graded exercise test on the wheelchair ergometer to 80% of age adjusted estimated maximal heart rate; and 3) N=20 one minute propulsion bouts on the wheelchair ergometer. During visit 2 participants will repeat the N=20 one minute propulsion bouts on the wheelchair ergometer. Wheelchair ergometer propulsion acclimation: Participants will complete a minimum of 2 minutes of wheelchair propulsion to acclimate. Additional propulsion time will be completed as needed. Propulsion workload will be varied during the acclimation. Acclimation propulsion may be repeated as needed during study participation. Submaximal wheelchair ergometer test protocol: Participants will rest quietly in the wheelchair for several minutes. After resting, participants will begin propelling at a comfortable speed at a low initial workload. Workload will be increased every minute. Propulsion speed will remain constant across all workloads. Test will end when participants reach 80% of age adjusted estimated maximum heart rate. Wheelchair propulsion workload assessment: Participants will complete 20 one-minute propulsion bouts at a self-selected speed. Each one minute propulsion bout will be followed by a 2 minute rest period. Each propulsion bout will be at a different workload. After the first 10 propulsion bouts, participants will be provided with an extended rest period (5 to 30 minutes). For each participant, the maximum workload to be tested is based on their estimated maximum workload. Estimate maximum workload is based on the Heart Rate-Workload relationship documented during the submaximal test. The workloads of the N=20 propulsion bouts will be divided into two groups of N=10 (Group A and Group B). The total workload of each group will be equal. Within each group, workload sequence is fixed and arranged in a non-ascending or descending order. Completion order of the groups will be counterbalanced within sex. Within participants, completion order will be counterbalanced across days
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
11
Participants will complete 20 one-minute manual wheelchair propulsion bouts. Each one minute propulsion bout will be followed by a 2 minute rest period. Each propulsion bout will be at a different workload. After every 10 propulsion bouts, participants will be provided with an extended rest period (5 to 30 minutes). For each participant, the maximum workload to be tested is based on their estimated maximum workload. Estimate maximum workload is based on the HR-Workload relationship documented during a prior sub maximal test to 80% of age adjusted maximum heart rate.
UAB/Lakeshore Research Colaborative Building
Homewood, Alabama, United States
Self-Selected Speed (meters per second)
Average linear propulsion speed during each completed propulsion cycle (i.e. contact+recovery) averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average Rolling Resistance (Newtons)
Average rolling resistance during each completed propulsion cycle (i.e. contact+recovery) averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Number of completed propulsion cycles used to generate the outcomes of interest
The number of complete propulsion cycles occurring in the specified time frame. A complete propulsion cycle is defined as beginning with the onset of contact with the pushrim and ending with the onset of contact of the next propulsion cycle. A propulsion cycle includes contact and recovery.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average resultant force (Newtons)
Average resultant force during the contact phase of each completed propulsion cycle averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average rate of rise of resultant force (Newtons per second squared)
Average rate of rise of resultant force during the contact phase of each completed propulsion cycle averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average push frequency (pushes per minute)
For the specified time frame, the total number of completed propulsion cycles divided by the time to complete all the propulsion cycles in seconds multiplied by 60 seconds.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average push length (Degrees)
The distance over which a propulsive torque is applied to the pushrim during the contact phase of each complete propulsion cycle averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average propulsive torque (Newton meter)
Average propulsive torque during the contact phase of each completed propulsion cycle averaged across all completed propulsion cycles in the specified time frame.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average push power output (Watts)
Average power during the contact phase of each each completed propulsion cycle averaged across all completed propulsion cycles in the time frame of interest. Push power output represents the energy the person applies to the pushrim during the contact phase.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average total work per push (Joules)
Total work during the contact phase of each completed propulsion cycle averaged across all completed propulsion cycles in the time frame of interest.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Average external power output (Watts)
Average external power output during the entire propulsion cycle (i.e. contact and recovery) averaged across all completed propulsion cycles in the specified time frame. External power output represents the energy expended by the user-wheelchair system.
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
Frequency of each unique propulsion pattern
For each complete propulsion cycle during the specified time frame, the recovery pattern will be classified into one of 5 categories: semi-circular, arcing, single loop, double loop, or indeterminate. The number of cycles and overall percentage in each category will be reported. Overall percentage is defined as \[number of cycles in a category/total number of cycles \* 100\].
Time frame: Seconds 20 to 40 of each 1 minute propulsion bout
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.