Research Review: Low prevalence of Genu Varum & Valgum Among Elementary School Children
By Stefanie DiCarrado DPT, PT, NASM CPT & CES
Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS
Original Citation: Karimi-Mobarake, M., Kashefipour, A., Yousfnejad, Z. The prevalence of genu varum and genu valgum in primary school children in Iran 2003-2004. (2005) Journal of Medical Science 5(1). 52-54. - ARTICLE
A - Normal knee alignment B - Genu Varus (bow legged) C - Genu Valgum (knock-kneed)
Why is this relevant?: Genu valgum (GVL) or "knock-kneed" has been correlated with ACL injuries (1). Other injuries due to altered knee alignment could include Patellofemoral Pain Syndrome, arthritis, and MCL/LCL rupture. The low prevalence of a developmental structural mal-alignment indicates most cases of GVL or genu varus (GVR) are related to correctable muscle imbalances and soft tissue mal-adaptation.
Study Summary
| Study Design | Descriptive cross-sectional study |
| Level of Evidence | III: evidence from non-experimental descriptive study |
| Subject Demographics |
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| Outcome Measures | Intercondylar & intermalleolar distance (measured with a tape measure) |
| Results |
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| Conclusions | A low prevalence in both GVR and GVL among young children suggests the altered knee angle in adults may be more related to muscle imbalances and soft-tissue mal-adaptation than structural development. |
| Conclusions of the Researchers | Structural abnormalities, specifically GVL are more common in females than males in elementary school children. Determining the tibial femoral angle can distinguish children with serious pathology from those with correctable mal-alignment. |
In a neutral leg, the load bearing angle (LBA) is equal to the hip knee ankle (HKA) alignment. With knee varus/valgus the HKA changes in relation to the LBA creating unequal wear & tear on the knee joint.
Review & Commentary:
This particular study is difficult to review as it is very short (not necessarily a limitation) and may have been translated from another language into English. The authors do not describe their methodology in detail but refer to an article that contains the methodology used (2). This is common practice, and not a flaw in the study unto-itself. The researchers do mention the part of the process used; measuring the distance between the femoral condyles and the medial malleoli. These measurements would provide information as to the alignment of the ankles relative to the knees. Researchers analyzed the data collected as described by three cited text books, but did not describe with-in this article (3,4,5).
Why is this study important?
The data presented here provides an interesting look at the structural knee alignment in young children who are developmentally "stable". That is, they have progressed in their physical development from infants with genu varus (GVR) to ambulatory toddlers -- a marker in devlopment that should result in a neutral knee angle. Children with persistent genu valgus (GVL) or GVR at this point in development may have a structural abnormalities that require monitoring, conservative intervention (therapy, braces, etc.), or surgery. The development of GVL or GVR later in life suggests that compensatory patterns and soft tissue adaptation as a cause and indicates corrective exercise at either the hip (for Lumbo-Pelvic Hip Dysfunction, LPHCD) or at the ankle (for Lower Leg Dysfunction, LLD ).
How does it affect practice?
The human movement professional should understand the prevalence of structural abnormalities occurring developmentally vs progressive alterations in muscle recruitment. A corrective exercise routine should first be implemented in cases of knee pain where the patient displays either static or dynamic GVR/GVL rather than "blaming" structural development for musculoskeletal pain.
How does it relate to Brookbush Institute Content?
Static and dynamic GVR (knees bow out) and GVL (knees bow in) related to muscle imbalance tend to follow a predictable patterns of dysfunction and may be related to problems within the lumbo-pelvic hip complex (LPHCD) and/or at the lower leg and ankle (LLD ). The Brookbush Institute encourages movement assessment for all individuals, including both static and dynamic postural assessment (Overhead Squat Assessment ), as well as goniometric, strength, joint mobility and special tests (when in one's scope of practice). Both the predictive models of LPHCD and LLD models indicate over-activity in the following muscle groups in a person who displays static or dynamic GVL: hip flexor complex (psoas , iliacus , TFL , rectus femoris , anterior adductors , sartorius ), hip internal rotators (TFL , gluteus minimus , anterior adductors ); the LLD expands the list by adding in tibial external rotators (biceps femori s, lateral gastrocnemius ) and ankle evertors (peroneals ). Underactive muscles within these models include hip extensors (gluteus maximus , semitendinosus and semimembranosus ) and hip external rotators (gluteus medius , gluteus maximus ).
In a person with static and dynamic GVR, the model changes slightly, as described in the LPHCD article - "The synergistic dominance seen in the piriformis , biceps femoris , and adductor magnus (possibly via communicating synergy at the sacrotuberous ligament) results in excessive external rotation as way to compensate for an inability to eccentrically decelerate femoral adduction and internal rotation in the presence of prime mover inhibition. This results in one small but meaningful change in our programming. Rather then these muscles being “long/over-active” they are now “short/over-active” implying they should be released and stretched."
The videos below include a sample corrective exercise routine for GVR as a result of LLD .
Gastro/Soleus Static Release
Dynamic Calf Stretch
Posterior Tibialis Activation Progression
Quick Tibialis Anterior & Tibial Internal Rotator Activation
Posterior Tibialis Reactive Activation
Tibialis Anterior Reactive Activation Progressions
Resisted Single Leg Balance with Reach and Progressions
Sources
2. Heath, C.H. and Staheli, L.T. (1993). Normal limits of knee angle in white children- Genu varum and genu valgum. Journal of Pediatric Orthopedics. 13. 259-62.
3. Morrisy, R., (2000). Lovell and Winter's Pediatric Orthopedics. Lipincot Williams Wilkins Co, Philadelphia. 5th edition. pp: 1065-84.
4. Sharred, W.J.W. (1993). Pediatrics Orthopedics and Factures. Blackwell Science Ltd, London. 3rd edition. pp: 422-36.
5. Tachdjian, M.O. (1996). Clinical Pediatric Orthopedics. Appelton and Lange Co, Stanford. 4th edition. pp 118-32.
© 2015 Brent Brookbush
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