Coffee Task
About the Coffee Task
The Coffee Task is a representative bilateral activity of daily living (ADL), during which individuals simulate brewing a cup of coffee with a pod-style coffee maker using 3 functional grasps (fist, pinch, point) and 5 grasp transitions.
The task was designed as an objective assessment tool that enables quantification of performance during grasp transitions - number of errors and completion time - in users of multi-articulating upper limb prostheses.
There are two versions of the task: segmented and continuous.
Segmented Task: Individuals are asked to attempt each of the 5 segments of the task until all parts of the segment, including a successful grasp transition, are completed. They receive up to 5 attempts per segment to complete, leaving the maximum accumulated error of 25 for the full task.
Continuous Task: Individuals are asked to complete the full task continuously as fast as they can while using as many correct grasp transitions as possible. They are not allowed to complete parts of the task designed to be completed by the prosthetic hand with their intact hand (dominant hand for those with bilateral amputation). Individuals receive up to 2.5 minutes to complete the task.
Materials needed:
Pod-style coffee maker with a small push-to-start button
2 beads
1 small cup that can fit under the coffee maker
Reusable coffee pod
Sugar packets
Sugar packet holder
Container for sugar packet trash
Video camera for scoring errors (segmented)
Stopwatch for timing (continuous)
All materials are laid out on the table whose height aligns with the participant’s anterior-superior iliac spine. The participant completes all tasks standing in front of the table.
The coffeemaker is placed on the contralateral side of the prosthesis. The cup is filled with the two beads and is placed on the ipsilateral side of the prosthesis. The trash container is placed laterally and distally to the cup. Sugar packets should be in a holder and aligned with the midline of the participant. The reusable coffee pod is also aligned with the midline of the participant, proximal to the sugar packets.
Place a video camera in front of the participant for scoring the number of errors.
Instructions for Unilateral Amputation
This novel assessment is called the Coffee Task. I will explain what the task sequence is and which prosthetic grasp to use to complete each segment of the task. The task sequence is as following:
Fi: Fist, Po: Point, Pi: Pinch
Use your intact hand to open the coffeemaker water reservoir. (Fi) Using Fist grasp, grab the cup with beads with your prosthesis and pour the beads into the reservoir. Maintain the fist grasp around the cup to place it underneath the dispenser.
(Pi) Open the pod holder with your intact hand and using the Pinch grasp, pick up the pod with your prosthesis. Place the pod you just grabbed in the holder using your prosthesis. Close the pod holder with intact hand.
(Po) Using the Point grasp, press the start button on the coffee maker with your prosthesis.
(Fi) Using the Fist grasp, grab the cup from underneath the dispenser with your prosthesis and place it anywhere on the table.
You may use your intact or your prosthesis to reach and grab the sugar. (Pi) Use both your intact hand and prosthesis with Pinch grasp to tear open the sugar packet. Pour at least 90% of the sugar into the cup, then place the empty packet in the trash container.
You will complete this task first in segments, and then continuously. In the segmented version, I will cue the specific segments of the task and you will repeatedly attempt each segment up to five times or until you complete the segments without any errors. Errors you may encounter include incorrect grasp transition, inability to change grasps, unintended hand opening, and dropped objects. The goal of the segmented version is to accomplish all segments of the task with the correct grasp transition and as few errors as possible.
You will then complete the continuous version of the task. You will start on my command and go through each segment from start to finish continuously. You do not need to wait for my cue to continue between segments. The goal of the continuous version is to complete the task quickly using the prescribed grasps. It is acceptable to complete a segment with an unprescribed grasp as long as the segment is completed using the specified hand (e.g., prosthesis v. intact).
Demonstration
Video Upload