A new muscle discovered? As a licensed massage therapist, I am a muscle specialist, but also an anatomy geek and a research nerd. Always combing the halls of the Massage Therapy Foundation and PubMed for the latest research studies, I am always surprised by how much we still have to learn about how the human body works. In the upcoming article to be published in the journal Clinical Anatomy, researchers in Switzerland have found a new muscle – tensor vastus intermedius- in the quadriceps! (This means we will have to change the name of the muscle group.- Quinticeps? )
The quadriceps femoris is traditionally described as a muscle group composed of the rectus femoris, vastus lateralis, vastus medialis, and deep to rectus femoris, the vastus intermedius. The researchers have found a second tensor-like muscle between the vastus lateralis and the vastus intermedius, hereafter named the tensor vastus intermedius. (TVI)
How did they find it? During the dissection of twenty-six lower limbs, special attention was paid to the nerves and blood vessels attached in this area. All muscles were traced separately from their origin to their insertion. In all twenty-six, a TVI was found, supplied by its own nerve and artery branches and merging separately into the quadriceps tendon into the medial aspect of the the patella – inner side of the kneecap. There are variations between subjects. In fact, four different variations were found during the study. It begins at the upper part of the femur between the insertions of the vastus lateralis and vastus intermedius and continues down the leg mainly as a thin tendon before joining the quadriceps tendon and ultimately attaching via the patellar tendon below your kneecap onto the tibia.
What does this mean for your massage or your workout? Not a whole lot. It’s always been there. You’re not going to notice a difference as this new muscle is likely unable to be differentiated from the surrounding tissue with palpation, but I always find it fascinating when researchers discover something new in the body. Just like this previous blog post about the recently discovered lymphatic system in the brain.
For more information read the abstract on PubMed here:
Grob, K., Ackland, T., Kuster, M., Manestar, M., & Filgueira, L. (2016). A newly discovered muscle: The tensor of the vastus intermedius. Clin. Anat. Clinical Anatomy, 29(2), 256-263.