Rectus femoris is one of the four quadriceps muscles. The other quadriceps muscles are vastus medialis, vastus lateralis, and vastus intermedius. Of these four muscles, rectus femoris is the most superficial and is the only to cross both the hip and knee joints; the others cross only the knee. The various functions of this muscle give personal trainers important considerations to take into account when facing postural distortions or knee/hip pain.
Origin and Insertion
Rectus femoris uniquely has two points of origin: at the anterior superior iliac spine (ASIS) and posteriorly at the acetabulum (the socket of the hip joint). All four quadriceps muscles attach to the patella and the tibia through the quadriceps tendon.
Rectus Femoris Function
All quadriceps muscles extend the knee; rectus femoris is also involved in hip flexion. It is used frequently in daily movements like walking, rising up from seated, or climbing the stairs. It is also extremely active in sports that involve running, sprinting, or kicking a ball.
Training Rectus Femoris
Because the quadriceps are a large muscle group, it is beneficial to train them in a fashion that two-joint muscles like rectus femoris require; such muscles deserve special attention because of their complexity.
Since this multi-joint muscle is the most superficial on the ventral thigh, those who want to see definition in their quadriceps will want to target it. Additionally, weakness in the quads has been connected to knee pain and, more specifically, osteoarthritis in the knees.
Leg extensions are designed to target the quadriceps, and it should be easy to find a leg extension machine in most gyms. Additionally, clients could try leg extensions with ankle weights if a machine is not available by standing on one leg and extending the other.
The leg press is another way to train rectus femoris with a compound movement.
Squats are an accessible and functional way to strengthen the quadriceps and prepare them for basic movements in your client’s daily life. These can be done with or without weight, and could progress to jump squats over time.
Lunges, similar to squats, are a classic bodyweight exercise that train the quadriceps. They can be progressed with the addition of dumbbells as your client builds strength.
Step-ups are another functional way to train rectus femoris. Using just a step or a bench, clients can step up one foot at a time with or without weights. Over time, the height of the step or the bench may increase to progress this exercise.
When targeting rectus, consider exercises that include both of its functions: hip flexion and knee extension.
Whether it’s for aesthetic or functional purposes, strengthening the quadriceps relies on the understanding of each of its muscles, and rectus femoris is significant.
Segal, N A et al. “Quadriceps weakness predicts risk for knee joint space narrowing in women in the MOST cohort.” Osteoarthritis and cartilage vol. 18,6 (2010): 769-75. doi:10.1016/j.joca.2010.02.002
Glass NA, Torner JC, Frey Law LA, Wang K, Yang T, Nevitt MC, Felson DT, Lewis CE, Segal NA. The relationship between quadriceps muscle weakness and worsening of knee pain in the MOST cohort: a 5-year longitudinal study. Osteoarthritis Cartilage. 2013 Sep;21(9):1154-9. doi: 10.1016/j.joca.2013.05.016. PMID: 23973125; PMCID: PMC3774035.