John Poppe, “Comparison of Pre and Post-Op Thoracohumeral Kinematics in Individuals with Rotator Cuff Tears”
Mentor: Alyssa Schnorenberg, Occupational Science & Technology
The rotator cuff (RC) is a group of muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) which contribute to the motion and stability of the glenohumeral joint. A tear in one or more RC muscles often results in pain and decreased shoulder mobility, which can make it difficult for the injured to perform activities of daily living (ADLs). This study examined the progress of standard RC tear rehabilitation by comparing injured and non-injured joint kinematics during a common ADL. Participants with an RC tear were recorded with a 15 camera Vicon T-Series system at 120 Hz performing a reach to back pocket task (simulating perineal care) with their injured and non-injured arms. Participants were evaluated 3 months before (pre-op), 3 months after (post-op 1), and 6 months after (post-op 2) RC repair surgery. An inverse kinematics model calculated the 3D thoracohumeral joint angles for each arm. The range of motion (ROM) in each plane was determined by taking the difference between the peak angles. One representative participant is reported. The coronal plane ROM of the injured arm was less at pre-op (7.3⁰±2.4⁰), similar at post-op 1 (17.4⁰±2.2⁰), and greater at post-op 2 (30.2⁰±3.6⁰), in comparison to the non-injured arm (15.8⁰±2.4⁰). The transverse plane ROM of the injured arm was less at both pre-op (15.9⁰±0.9⁰) and post-op 1 (18.0⁰±2.2⁰), and similar at post-op 2 (31.4⁰±3.8⁰) in comparison to the non-injured arm (27.4⁰±4.2⁰). The sagittal ROM of the injured arm was similar at pre-op (50.7⁰±1.4⁰), and more at post-op 1 (52.1⁰±0.3⁰) and post-op 2 (57.1⁰±0.9⁰) in comparison to the non-injured arm (47.0⁰±6.3⁰). We successfully calculated the 3D thoracohumeral joint kinematics during the back-pocket ADL before and after a RC repair surgery for one participant. Current work is underway to include more participants to elucidate patterns of rehabilitation.
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Hello! My name is John Poppe, I’m a sophomore studying computer science and computer engineering, and I’ve been working on this project since October. Feel free to post any questions you may have regarding the project in the comments, and I’ll get back to you as soon as possible!
Very nice work, John. Your presentation of the data is exceptionally clear. I wonder, as you apparently do as well, about the degree to which the differences in results (especially for subjects 3 and 5) might be explained in terms of modification of movement to accommodate injury. Interesting avenues for follow-up…
It’s a very interesting avenue indeed! I think it would be very interesting to do a follow up study restricting the participants motion to exactly mirror their non-injured arm, but doing so is more easily said than done. Another interesting avenue to consider for difference in results is how strictly these subjects adhered to their physical therapy post-surgery. For this project, we assumed that every subject did exactly what they were told to do by their doctor and other healthcare providers, however its possible that each subject took some liberty with rehabilitation plan.
Great work, John. Very interesting! Given the supraspinatus’ role in arm abduction, did you consider studying other ADL’s that involve more abduction at the shoulder joint?
Hey Caleb! Thank you for the kind words! All of the ADL’s were considered for this project, but it was decided early on that looking at every ADL would be too large for the scope of the project. I do think it would be very interesting to examine an ADL with a larger range of motion in the non-injured arm in any of the planes of motion
Great work, John!!