Author: Kevin B. Rosenbloom, C.Ped, Sports Biomechanist
Medial rotation is one of hip joints movements that will be addressed below along with an exploration into the muscle bodies that contribute to this movement and brief research about each of the muscle to entice the curious.
Medial Rotation Essentials
Hip medial rotation is the inward rotation of the thigh and leg (along the transverse plane) at the hip joint. The range of motion has been estimated to extend up to 40° for most individuals (Moses 2014) with a mean range of 32-36° (Roaas & Andersson 1982, Cheatham et al. 2017). The adductor group (longus, brevis, magnus), gluteal group (maximus, medius, minimus) and tensor fascia lata are the most significant contributors to medial rotation (Visible Body 2019). The semitendinosus and semimembranosus assist in medial rotation when the femur is in an extended position (Saladin 2010).
The semitendinosus is a fusiform muscle that is part of the hamstring group. It originates from the posterior ischial tuberosity along a shared tendon with the semimembranosus and the biceps femoris long head. Its body runs alongside the medial border of the biceps femoris long and inserts onto the medial superior tibial shaft, just distal to the tibial condyle and gracilis’ insertion, and beneath the sartorius.
Along with other thinner and elongated muscles like the sartorius or gracilis, the semitendinosus muscle have long fiber lengths, but a relatively small diameter for its cross-section. The benefits of these characteristics are that these muscles can perform large muscle excursions while only involving low levels of force (Lieber & Fridén 2001). In a separate topic involving this muscle, a research group determined the age rate of apoptosis regulatory proteins within semitendinosus cells (Park et al. 2010). With the expansion of this research, it has been suggested to have a wide range of applications, including the monitoring of muscle deterioration and physical therapy.
Another hamstring member, the semimembranosus also originates at the posterior ischial tuberosity along a shared tendon with the semitendinosus and biceps femoris long head. Its thick body runs alongside the medial border of the semitendinosus and inserts into the posterior surface of the medial tibial condyle. Its tendons expand upward and laterally (towards the lateral femoral condyle) and downward covering the popliteus muscle. This gives it significant function in the knee joint.
A case study testing the neurosensory functions of the meniscus in the knee concluded that the only response observed was linked to the semimembranosus and the posterior horn of the medial meniscus (Saygi et al. 2005). Variations of the muscle have shown it can be reduced, absent or even doubled (Gray 1918).
It is quite clear that the mechanisms that form the body, especially the portions of the lower extremities, are complex, with even single organisms capable of displaying multiple functions. Several muscles in the pelvic region have multiple functions and have been briefly discussed in other Kevin Orthopedic summaries. In order to avoid monotony, it is suggested to review the summaries below for additional information on other medial rotator muscles:
Muscle Overview - Hip Medial Rotators
Figure 1. Sketch of hip medial rotators (right), posterior view.
Adductor longus 
Adductor brevis 
Adductor magnus 
Gluteus maximus 
Gluteus medius 
Gluteus minimus 
Tensor Fascia Lata 
*Medial rotators during hip extension
References & Works Cited
Barclay, T. 2018. “Anatomy Explorer,” innerbody.com. Accessed 19 Mar 2019. https://www.innerbody.com/anatomy/muscular/leg-foot.
Cheatham, S., Hanney, W. J., Kolber, M.J. 2017. “Hip Range of Motion in Recreational Weight Training Participants: A Descriptive Report,” International Journal Sports Physical Therapy 12(5): 764-773. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5685413/.
Gray, H. 1918. “The Muscles and Fasciæ of the Lower Extremity,” Anatomy of the Human Body, 20th Ed. Lead & Febiger. Philadelphia & New York, USA. 475, 479-480.
Lieber, R. L., Fridén, J. 2001. “Clinical Significance of Skeletal Muscle Architecture,” Clinical Orthopaedics and Related Research383: 140-151. http://muscle.ucsd.edu/More_HTML/papers/pdf/Lieber_CORR_2001.pdf.
Moses, S. 2014. “Hip Range of Motion,” Family Practice Notebook. Accessed 27 Mar 2019. https://fpnotebook.com/Ortho/Exam/HpRngOfMtn.htm.
Park, S. Y., Kim, H. Y., Lee, J. H., Yoon, K. H., Chang, M. S., Park, S. K. 2010. “The Age-Dependent Induction of Apoptosis-Inducing Factor (AIF) in the Human Semitendinosus Skeletal Muscle,” Cellular & Molecular Biology Letters 15: 1-12. https://cmbl.biomedcentral.com/track/pdf/10.2478/s11658-009-0030-4
Platzer, W. 2004. Color Atlas of Human Anatomy, Vol. 1: Locomotor System 5th Ed. Thieme. New York, USA.
Quinn, E. 2019. “Generally Accepted Values for Normal Range of Motion (ROM) in Joints,” verywellhealth.com. Accessed 19 Mar 2019. https://www.verywellhealth.com/what-is-normal-range-of-motion-in-a-joint-3120361.
Roaas, A., Andersson, G. B. J., 1982. “Normal Range of Motion of the Hip, Knee and Ankle Joints in Male Subjects, 30-40 Years of Age,” Acta Orthopaedica Scandinavica, 53:2, 205-208. https://www.tandfonline.com/doi/abs/10.3109/17453678208992202.
Saladin, K. R. 2010. Anatomy & Physiology: The unity of form and function. 5th Ed. McGraw-Hill. New York, USA.
Saygi, B., Yildirim, Y., Berker, N., Ofluoglu, D., Karadag-Saygi, E., Karahan, M. 2005. “Evaluation of the Neurosensory Function of the Medial Meniscus in Humans,” Arthroscopy: The Journal of Arthroscopic and Related Surgery 21; 12: 1486-1472. http://www.drortopedi.com/bilimsel-yayinlar/evaluation-of-the-neurosensory-function-of-the-medial-meniscus-in-humans.pdf.
Visible Body. 2019. “Muscle Premium,” VisibleBody.com. Purchasable Application. Accessed 21 Feb 2019.
Kevin B. Rosenbloom, C.Ped, Sports Biomechanist
Kevin B. Rosenbloom, founder and president of Kevin Orthopedic, is a renowned certified pedorthist and sports biomechanist practicing in Santa Monica, CA. With his continuing research on the historical development of foot and ankle pathologies, comparative evolution of lower extremities and the modern environmental impacts on ambulation, he provides advanced biomechanical solutions for his patients and clients.