It’s no secret that people move differently, but researchers who carefully tracked muscle movements of study participants during exercise think the differences may go even deeper than variation in movement styles. Their conclusion: humans possess muscle activation “signatures” that are as unique to each individual as fingerprints or iris structure. Not only could these patterns be used to identify an individual, they write, but finding a person’s activation strategies could help to identify the potential for future musculoskeletal problems, and better tailor treatments to individual patient needs.
Researchers analyzed movement patterns of 53 individuals using surface electromyography (EMG) on their legs as they pedaled on a stationary bicycle and walked on a treadmill. Using a machine learning protocol, authors of the study tracked activation patterns from 8 muscles of the right leg: the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), soleus (SOL), tibialis anterior (TA), and biceps femoris-long head (BF). They used the data to establish unique muscle activation signatures recorded during an initial session. Participants then returned for a second round of the same activities between 1 and 41 days after the first (average, 13 days), allowing researchers to evaluate the similarities between activation patterns observed at each session.