Project: Effect of wheelchair speed and propulsion pattern on elbow and glenohumeral joint ranges of motion
Goals: To understand how motion analysis data is collected and analyzed for wheelchair mobility during 2 activities. To determine if differences exist between speeds and propulsion patterns at the elbow and glenohumeral joints.
Activity 1: Use motion analysis techniques to analyze peak joint angles and ranges of motion during two different speeds of wheelchair propulsion
Provided is upper extremity data that was calculated from the marker trajectories that were acquired during motion analysis of wheelchair propulsion at two different speeds: 40 beats per minute (bpm) and 60 bpm. For each speed, the same able-bodied individual (non-wheelchair user) propelled the manual wheelchair on a dynamometer (wheelchair treadmill) for three trials. A metronome was used to keep the subject at a steady speed; each time the metronome sounded the user made contact with the handrim effectively starting another stroke cycle (expressed in beats per minute). The subject used the same self-selected propulsion pattern at each speed of testing.
Activity 2: Use motion analysis techniques to analyze peak joint angles and joint ranges of motion during wheelchair propulsion with two different propulsion patterns
Provided is upper extremity data that was calculated from the marker trajectories that were acquired during motion analysis of wheelchair propulsion using two different propulsion patterns: semi-circular (SC) and single-looping over propulsion (SLOP). For each speed, the same able-bodied individual (non-wheelchair user) propelled the manual wheelchair on a dynamometer (wheelchair treadmill) for three trials. A metronome was used to keep the subject at a steady speed; each time the metronome sounded the user made contact with the handrim effectively starting another stroke cycle. The same speed was used for both propulsion patterns.
Data
The data is provided in an Excel spreadsheet and is structured as such:
For each activity, there are two Excel worksheets. For activity 1-speed: the first tab (40 BPM) contains the data for the 40 bpm trials and the second tab (60 BPM) for the 60 bpm trials. For activity 2-patterns: the third tab (SC) contains data for the SC pattern and the fourth tab (SLOP) contains data for the SLOP pattern. Within each sheet the data is organized the same way, as described next.The data is the time series of the subject’s left hand side elbow and glenohumeral joint angles for each of three trials. For the elbow, angle Y represents pronation (+) and supination (-) and angle Z represents flexion (+) and extension (-). For the glenohumeral joint, angle X represents adduction (+) and abduction (-), angle Y represents internal (+) and external (-) rotation, and angle Z represents flexion (+) and extension (-). The first column (A) is the percentage of the wheelchair stroke cycle, from 0-100%. If you plot one of the angles on the Y-axis and the percentage stroke cycle on the X-axis, you will see how that joint moved in that plane from the start of the stroke cycle (0%, hand contact with the handrim) through release of the handrim (transition to recovery phase) to the end of the stroke cycle (100%, after the hand has been brought back to the handrim and is about to contact the handrim for the next stroke cycle).
This time series data is listed for each of these joint angles for all three trials performed by the test subject. Instructions
Use the data provided and Excel (or other software) to do the following:
1) Determine the maximum angle, minimum angle and range of motion for each joint angle, for each trial
o Maximum Angle – Use Excel’s built in functions
In an Excel cell, type “=max(”, then highlight the column of data you want Excel to find the max within, then hit “Enter” on your keyboard
o Minimum Angle – Use Excel’s built in functions
In an Excel cell, type “=min(”, then highlight the column of data you want Excel to find the max within, then hit “Enter” on your keyboard
o Range of Motion (Max Angle – Min Angle)
2) Then, use the data from (1) to calculate the average and standard deviation of the maximum angle, minimum angle and ROM for each joint angle for each speed
o Average the maximum value from each of the 3 trials for the 40 bpm task.
In an Excel cell, type “=average(”, then choose the first data point you want to include in the average (by clicking on the cell), then hit the “,” (comma) and choose the next data point and again hit comma, then choose the last data point and hit “Enter”.
o Determine the standard deviation of the maximum values for each of the 3 trials for 40 bpm task.
In an Excel cell, type “=stdev.s (”, then choose the first data point you want to include in the average (by clicking on the cell), then hit the “,” (comma) and choose the next data point and again hit comma, then choose the last data point and hit “Enter”.
o Repeat this process for the minimum values of each joint angle, and then again for the ROM values for each joint angles of the 40 bpm task.
o Lastly, repeat this whole process for the 60 bpm task.
3) (Optional)Use the data from (1) to perform a Student’s t-test to compare the maximum, minimum and ROM values of each joint between the 40 bpm and the 60 bpm tasks.
o In an Excel cell, type “=t.test(”, then select the maximum joint angle value for each of the 3 trials for the 40 bpm task at the same time, then hit the comma, next highlight the 3 maximum joint angle values from the 60 bpm task, then hit comma again, type 2 (for two-tailed test – we are testing to see if there is a difference), then hit comma, type 2 (for two-sample equal variance – homoscedastic) and hit “Enter”.
The resulting number is the p-value of the t-test. Please use a p-value of 0.05 for reporting statistically significant differences.
4) Calculate the average time series data of the 3 trials for each joint angle at each task speed
o Take the average of the joint angle from each of the three trials during 40 BPM at EACH of the stroke cycle percentages. (So 101 averages will be calculated for each joint angle!) This process will yield an average curve of the three trials that you can plot against the percent stroke cycle.
Ex: You will average the following numbers together: elbow flexion/extension angle at 0% from trial 1, and 0% from trial 2, and 0% from trial 3. This results in the average elbow flexion/extension angular position at 0% stroke cycle for this subject. Then repeat for 1%, and so on. This should be done for each angle at each percentage.
• Excel hint: if you hover over the bottom right hand corner of a selected cell, a black plus sign will appear. If you click and drag, the equation in the originally highlighted cell will be copied across the cells you drag over/highlight. Give it a try, and then double click on one of the cells you expand the equation to and check that the correct cells are being pulled into the equation.
o Repeat this calculation for the other speed.
5) Once the times series averages for each joint angle during each task speed have been calculated, plot each of them (on the y-axis) against the percentage stroke cycle (on the x-axis). For these plots, please have the joint angle from each speed plotted on the same graph, overlayed.
o Ex: Plot the average elbow flexion/extension angle for the 40 bpm task on the same graph as the average elbow flexion/extension angle for the 60 bpm graph. (Joint angles will be on the y-axis and the percentage stroke cycle will by one the x-axis) This way you can compare the two tasks more easily.
o Please use the Scatter Plot with Smooth lines.
6) Lastly, repeat all of these steps for Activity 2-Propulsion Patterns, plotting and comparing the SC pattern and the SLOP pattern.
Short Paper – Activity Write-up
Once all of the data is processed, please follow the instructions below for the paper.
The purpose of this project is to practice some simple data calculations and create commonly used tables and figures used for kinematic motion analysis data and then discuss your findings using references to support your claims.
You will be using the provided data and your data processing results to provide recommendations for propulsion speed and pattern, with references to support your claims.
Your paper should be structured as follows:
Introduction
In a short paragraph described the purpose for using motion analysis to analyze manual wheelchair propulsion. What are some of the common problems that most manual wheelchair users encounter and how could this information be helpful in combating them.
Methods
Data Collection
In another short paragraph describe how this data was collected. While you were not present for the actual data collection, you have been provided the main, important details above. If you are interested in any further details, please contact me. I am not expecting this to be very involved.
Data ProcessingIn this paragraph you will describe any important information on how your results were determined/calculated. Anybody with the same data should be able to understand and replicate what you did. (Note: You do not need to describe how you calculated an average, etc., just that you did calculate it).
The introduction and methods section should be brief. The remaining sections will carry the most weight.
Results
Here you will present all of the results you tabulated and graphed. Please present the results that you found.
Include the following for EACH activity:
Include a table (or multiple tables) displaying the average and standard deviation of the maximum angle, minimum angle, and ROM for each joint angle at each speed. (Optional: Indicate which of these values were statistically significantly different between the two variations of the task (p>0.05)).
Plots of each joint angle (y-axis) vs the percentage wheelchair cycle (x-axis) with both activity variations on the same plot (ex: elbow flexion/extension for 40 bpm and 60 bpm on the same graph)
There will be 2 pages of graphs. One the first page please have both the elbow angles and on the second page, please included all three GH joint plots. You will have 5 plots total (2 elbow + 3 GH over 2 pages) for each activity.
Discussion
In this section, please discuss the results. Postulate why the results turned out the way they did and use references to support your claims. Discuss the meaning and significance of the results. Remember that the test subject was an able-bodied, non-wheelchair using individual.
Specifically be sure to include answers to the following questions WITHIN the discussion section.
• Based on your findings in the data and literature, what speed do you recommend for wheelchair propulsion of an adult and why? Please support your answer with at least 1 journal article citation.
Remember that the test subject was an able-bodied, non-wheelchair using individual.
o Could this recommendation change based on pathology?
o Would there be situations when you would make a different recommendation?
• Based on your findings in lab and literature, what propulsion pattern do you recommend for an adult and why? Please support your answer with at least 1 journal article citation.
Remember that the test subject was an able-bodied, non-wheelchair using individual.
o Could this recommendation change based on pathology?
o Would there be situations when you would make a different recommendation?
• Discuss advantages and disadvantages or limitations of this study?
o In addition to other thoughts, specifically address 2-3 advantages of using motion analysis to measure range of motion as compared to a goniometer?
Technical Requirements
• 3 – 4 pages (not including tables, figures and references)
o It is expected that the Introduction, Methods and Results (not counting tables or figures) would each be about 0.5 – 0.75 pages and the Discussion would be 1.5 to 2.5 pages. These are not required lengths, just estimations for your help; if you are shorter or longer on any of these sections, and have included the required information, that is acceptable.
o Double-spaced
o Page numbers
o Figures for results may all be placed in Appendices if desired, with proper captions.
• References:
o At least 3, peer-reviewed, professional journal articles for undergraduates and at least 4 for graduates.
o You will likely use 1 or 2 citations in the introduction and 2 or 3 in the discussion section. Depending on the references, they may be able to be used in both sections.
o IEEE or APA format
• Tables should have titles above the table and referenced within the paper as (Table #).
o Provide enough detail the table could standalone and make sense.
• Figures should have captions below the figure and referenced within the paper as (Fig. #).
o Provide enough detail the table could standalone and make sense.
• In all tables and figures:
o Be sure the text is legible
o Include units, legends and axis titles where appropriate
Sample Solution
