My Infectious Disease Doctor used to have me do this same type of resistance test to measure my strength. I have severe neuropathy from Lyme and she was trying to determine if my nerve damage was also causing muscle fatigue and weakness. She would also check all of my reflexes at each visit and found that some of them do not respond correctly. Do you have neurological lyme issues?
Hope this helps.
Peace and Healing
Lyme Disease - Doxycyline, IV-Rocephin, Amoxicillin, Azithromycin.