Human Movement Science & Functional Anatomy of the:

Rectus Femoris

by Brent Brookbush MS, PES, CES, CSCS, ACSM H/FS

& Stefanie DiCarrado SPT, NASM - CPT, CES

Thigh Musculature - Note the superficial position, depth and attachments - http://classconnection.s3.amazonaws.com/14/flashcards/1310014/png/screen_shot_2012-03-21_at_10956_pm1332361111874.png

Rectus Femoris:

• Origins: Tendinous attachment via the anterior inferior iliac spine (AIIS) and attachment of deeper fibers (reflected head) to a groove on the superior border of the acetabulum and anterior joint capsule (3, 11).
• Insertion: Inserts into the quadriceps tendon via a broad and thick aponeurosis which occupies the lower two-thirds of its posterior surface, blending with tendinous ends of the vastus lateralis, vastus medialis, and vastus intermedius to form the patellar tendon and insert into the base of the patella. The quadriceps tendon continues inferiorly as the patellar ligament, with investing fascial slips into the medial retinaculum, lateral retinaculum, anterior capsule and inserting into the tibial tuberosity (11).
  • Proximally, the rectus femoris is bordered by the tensor fasciae latae (TFL) superficially and laterally and the sartorius superficially and medially. Both muscles form an inverted "V" through which the rectus femoris emerges as it travels to its distal attachment on the patella (3). The rectus femoris is the most superficial quadriceps muscle bordered by the vastus medialis medially, and vastus lateralis laterally and the vastus intermedius passing deep to the rectus femoris.
  • You can palpate the muscle easily from the anterior aspect of the thigh with the leg positioned in slight hip and knee flexion. Begin by locating the patella and AIIS (find the ASIS, move inferiorly & medially) and then follow the path between these two points. The muscle is approximately 2-3 fingers width across. Asking the person to extend their knee will make the rectus femoris more pronounced (14).
• Nerve: Femoral nerve via the lumbar plexus originating from nerve roots L2 - L4.
• Action:
  • Extensor of the knee
  • Flexor of the the hip

The origin of the reflected head of the rectus femoris is the thin red oval just superior to the acetabulum (hip socket) - Grey's Anatomy: 20th Edition - http://aol.bartleby.com/107/Images/large/image235.gif

Integrated Function:

• Stabilization:
  • Stabilization of the hip
  • Stabilization of the tibiofemoral joint
  • Stabilization of the patellofemoral joint
    • may play a role in sacroiliac joint alignment via contribution to rotation of the innominate
    • may play a role in the reinforcement of the hip and knee capsules
• Eccentrically Decelerates:
  • Knee flexion
  • Hip extension
  • May contribute to eccentric deceleration of adduction when the hip is in extension
• Synergists:
  • The rectus femoris works synergistically with the vastus medialis, vastus lateralis, vastus intermedius to extend the knee.
  • As a hip flexor the rectus femoris works synergistically with psoas , iliacus , tensor fasciae latae (TFL) , sartorius and anterior adductors .
  • Although it may not be an active or purposeful synergy, over-activity and adaptive shortening of the rectus femoris may deflect the femur into abduction during hip extension past neutral along with a short/over-active sartorius and TFL . This is most notable in Lower Leg Dysfunction (LLD) , Lumbo Pelvic Hip Dysfunction (LPHCD) , or Sacroiliac Joint Dysfunction (SIJD) and is often related to hip and/or knee pain. A common sign of this "dysfunctional synergy" in a gym setting is abduction of the back leg during the eccentric phase of sagittal plane lunge.

Note how superficial the rectus femoris is in reference to the other quadriceps muscles. In this diagram we see the rectus femoris emerging from underneath the TFL and sartorius as it travels inferiorly between the vastus lateralis and vastus medialis to their common insertion in the quadriceps tendon. -http://en.wikipedia.org/wiki/File:Rectus_femoris.png

Arthrokinematics:

• This muscle plays a role in the arthrokinematics of the knee and hip joints.
  • Hip: The rectus femoris contributes to an anterior and superior glide of the femoral head in the acetabulum.
  • Knee: The quadriceps muscles collectively pull on the tibia causing anterior translation of the tibia on the femur during open chain knee extension and posterior translation of the femur on the tibia during closed chain knee extension (note: same relative joint motion).
  • Patellofemoral Joint: The rectus femoris may contribute to superior migration (patella alta) and lateralization of the patella in the femoral trochlea.
    • It could be that the rectus femoris in particular, is more influential in its role on patellar mechanics as the relative length of the muscle changes during hip flexion - for example, playing a special role in creating superior glide of the patella during the initial swing of gate as the rectus femoris contracts to assist in hip flexion (hip and knee flexion) and eccentrically decelerates inferior glide as the knee is extended and the hip extends in preparation for heel strike.

Note that the rectus femoris is bordered laterally by the vastus lateralis, medially by the vastus medialis and is superficial to the vastus intermedius - http://www.anatomyatlases.org/firstaid/ThighInjury.shtml

Fascial Integration:

My Fascial Hypothesis: Large fascial sheaths not only play a role in the transmission of mechanical force, but may also play a role in dictating the function of muscular synergies. This is likely caused by reducing or increasing tone of invested musculature via reflex arcs formed between mechanoreceptors imbedded in the connective tissue and the attached musculature. In this way my view of fascia differs slightly from noted expert on the subject Tom Myers. I think of these large fascial sheaths (specifically the thoracolumbar fascia, iliotibial band, and abdominal fascial sheath) as natures "mother board." A place for mechanical information to be communicated to the nervous system for more efficient recruitment of the muscular system. Despite having a slightly different philosophy it does not change the fact that fascia plays an important communicative role in the human body and we have Tom Myers to thank for his work.

Fascial Integration of the Rectus Femoris:

• Proximal Attachment: Despite scouring various texts and images I could not find any fascial continuity between the proximal attachments of the rectus femoris and other musculature. I had hoped that the "functional relationship" between the TFL , Sartorius , and Rectus Femoris discussed above would reveal itself as a group of muscles fascially intertwined at the anterior ilium, but this is not the case. The reflected head of the rectus femoris and it's attachment to the anterior capsule does seem to play a significant role in those complaining of "impingement type pain" in the anterior and inferior hip. These individuals have a propensity to present with a significant decrease in extensibility (Ely's Test ) and trigger/tender points.
• Distal Attachment: Like the proximal attachment it is hard to implicate the rectus femoris in fascial synergies - at least independent of other quadriceps muscles. The investing fibers into the lateral retinaculum and anterior capsule may implicate the rectus femoris in synergies that include the biceps femoris , TFL , fibularis and tibialis anterior muscles via the iliotibial band and complex network of fascia in the lateral knee, but based on my practical experience I have not seen evidence of this relationship. It may be that the only fascial continuity between the rectus femoris and other muscles is the quadriceps tendon, ensuring optimal activity of the quadriceps group as a whole.

Cadaver dissection of the lower extremity – http://myampgoesto11.tumblr.com/online-courses/online-courses/post/16940081948/day-5-of-cadaver-dissection

Behavior in Postural Dysfunction:

This muscle is prone to adaptive shortening and over-activity, although chronic and/or traumatic pathology of the knee (especially, resulting in edema) may result in fairly dramatic under-activity of all quadriceps muscles. Quad Sets and Progressions may be used for quadriceps activation; however, generally the rectus femoris is specifically addressed with release and stretching techniques due to length/activity changes relative to postural dysfunction.

In Upper Body Dysfunction (UBD)  the rectus femoris plays no significant role.

In Lower Leg Dysfunction (LLD)  the rectus femoris plays an accessory role. This may be due to arthrokinematic receptor activity leading to facilitation in response to knee pain, or due to the functional synergy between the rectus femoris, TFL and sartorius discussed above. The effects of this functional synergy is likely most note worthy in those individuals who present with "Knees Bow-Out" during an Overhead Squat Assessment. Facilitation in response to pain is a practical note based on my own experience. It appears that rectus femoris over-activity and adaptive shortening is often seen in conjunction with knee pain, and must be addressed to regain optimal movement. As this is a common symptom of LLD the rectus femoris may need to be added to this predictive model.

In Lumbo Pelvic Hip Complex Dysfunction (LPHCD)  the rectus femoris is short and over-active as a hip flexor, contributing to the anterior pelvic tilt seen in his dysfunction. In Sacroiliac Joint Dysfunction (SIJD)  it is common to see the asymmetrical changes, in which the rectus femoris is short/over-active opposite the side of sacroiliac joint dysfunction but unaffected on the ipsilateral. .

In short, this is a muscle that is addressed with release techniques and lengthening. Self-administered techniques are very effective and easily implementable. See the videos below.

Clinical Implications:

• Low back pain
• Hip impingement
• Arthrokinematic dysfunction of the hip
• Sacroiliac joint pain and dysfunction via asymmetrical rotation of pelvis
• Anterior knee pain
• Chondromalacia Patella
• When the rectus femoris is extremely over-active it may be the source of pain, becoming over-worked and trigger point laden during an individuals highest intensity activity.

Signs of Altered Length/Tension and Tone:

• Overhead Squat:
  • Anterior Pelvic Tilt: Short/Over-active
  • Excessive Forward Lean: Short/Over-active
  • Knees Bow Out: Short/Over-active
• Goniometric Assessment
• Decreased Knee Flexion in Prone < 145°
• Decreased Hip Extension (Modified Thomas Test with a flexed knee) Approximately < 10 - 15° hip extension & < 90°knee flexion
• Specific Flexibility Assessment
• Positive Ely's Test
• Palpation of the Rectus Femoris:
  • See image below for common trigger point locations and referral pain pattern for active trigger points.

Rectus Femoris Trigger Points and Referral Pain Pattern - http://imbuebody.com/online-courses/online-courses/front-and-inner-thigh-pain/

Exercises involving the Rectus Femoris:

Self-administered Static Release for Rectus Femoris (Anterior Thigh Active SA Release)

Self-administered Stretch for the Rectus Femoris (Kneeling Hip Flexor Stretch):

Active Stretch for Rectus Femoris:

Dynamic Stretch for Rectus Femoris:

Manual Rectus Femoris Stretch (Thomas Test Position Hip Flexor Stretch):

Bibliography:

1. Phillip Page, Clare Frank , Robert Lardner , Assessment and Treatment of Muscle Imbalance: The Janda Approach © 2010 Benchmark Physical Therapy, Inc., Clare C. Frank, and Robert Lardner
2. Dr. Mike Clark & Scott Lucette, “NASM Essentials of Corrective Exercise Training” © 2011 Lippincott Williams & Wilkins
3. Donald A. Neumann, “Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation – 2nd Edition” © 2012 Mosby, Inc.
4. Michael A. Clark, Scott C. Lucett, NASM Essentials of Personal Training: 4th Edition, © 2011 Lippincott Williams and Wilkins
5. Leon Chaitow, Muscle Energy Techniques: Third Edition, © Elsevier 2007
6. Tom Myers, Anatomy Trains: Second Edition. © Elsevier Limited 2009
7. Shirley A Sahrmann, Diagnoses and Treatment of Movement Impairment Syndromes, © 2002 Mosby Inc.
8. David G. Simons, Janet Travell, Lois S. Simons, Travell & Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition,© 1999 Williams and Wilkens
9. Cynthia C. Norkin, D. Joyce White, Measurement of Joint Motion: A Guide to Goniometry – Third Edition. © 2003 by F.A. Davis Company
10. Cynthia C. Norkin, Pamela K. Levangie, Joint Structure and Function: A Comprehensive Analysis: Fifth Edition © 2011 F.A. Davis Company
11. Florence Peterson Kendall, Elizabeth Kendall McCreary, Patricia Geise Provance, Mary McIntyre Rodgers, William Anthony Romani_, Muscles: Testing and Function with Posture and Pain: Fifth Edition © 2005 Lippincott Williams & Wilkins_
12. Brent Brookbush, Fitness or Fiction: The Truth About Diet and Exercise © 2011 Brent Brookbush - http://www.amazon.com/Fitness-Fiction-Truth-About-Exercise/dp/0615503012
13. Carolyn Richardson, Paul Hodges, Julie Hides. Therapeutic Exercise for Lumbo Pelvic Stabilization - A Motor Control Approach for the Treatment and Prevention of Low Back Pain: 2nd Edition (c) Elsevier Limited, 2004
14. Andrew Biel, Trail Guide to the Human Body: 4th Edition, © 2010

© 2013 Brent Brookbush

Questions, comments, and criticisms are welcome and encouraged