Knee Abduction and Adduction in Running: Understanding, Measuring, and Preventing Injuries

Running is one of the most accessible and widely practiced forms of exercise, but it comes with a high risk of injury. Studies suggest that up to 70% of runners experience injuries annually (Van Gent et al., 2007), with the knee being the most commonly affected body part, particularly in female runners (Sakaguchi et al., 2014). Knee abduction and adduction are key biomechanical factors in the development of knee injuries. Understanding this movement, its implications in injury mecanisms, and strategies for prevention can help runners improve performance and stay injury-free.

Figure 1: (a) Knee abduction (knee valgus). (b) Knee adduction (knee varus) (Ferber and Macdonald, 2014).

What is Knee Abduction and Adduction?

Knee abduction and adduction refer to side-to-side movements of the knee that occur in the frontal plane, (vertical plane dividing the body into front and back halves).

Figure 2: Human body on the frontal plane with front (left picture) and a back views (right picture).

• Knee abduction occurs when the tibia moves away from the center line of the body. The knee collapses inward, and the lower leg shifts outward. Knee abduction is often associated with hip adduction and foot pronation, a combination known as knee valgus or "knock knees.”
• Knee adduction is the opposite mouvement, where the tibia moves toward the center line of the body (Perry & Burnfield, 2010). Knee adduction is often associated with hip abduction and foot supination, a combination known as knee varus or “bowlegs”.

During dynamic activities like running, these movements can be influenced by hip, foot, and ankle placement but also by the upper chain, contributing to overall knee stability and alignment.

Why is Knee Abduction/Adduction Important?

Knee abduction and adduction angles influence lower limb biomechanics and injury risk.

Excessive knee abduction has been associated with:

• Patellofemoral pain (PFP): A knee collapsing inward alters quadriceps mechanics, potentially contributing to PFP (Powers, 2003; Huberti & Hayes, 1984; Elias et al., 2004).
• Anterior cruciate ligament (ACL) injuries: Female athletes with increased knee abduction angles and high abduction loads are at greater risk of ACL injuries (Hewett et al., 2005).
• Compensatory mechanisms: Runners with greater knee abduction may exhibit smaller rearfoot eversion (pronation) to counteract increased hip adduction, a phenomenon more pronounced in female runners (Sakaguchi et al., 2014).

While knee abduction (knee valgus) is often discussed in relation to running injuries, knee adduction (knee varus) also plays a role in injury risk, particularly in conditions affecting the lateral knee compartment. Increased knee adduction during running has been linked to iliotibial band syndrome (ITBS) (Baker et al., 2018; Noehren et al., 2014), a common overuse injury in runners.

These findings suggest that knee position should not be overlooked when evaluating running-related injuries. Addressing excessive knee abduction or adduction through strength training, neuromuscular retraining, and gait modifications may help reduce injury risk and improve overall running mechanics.

How is Knee Abduction/Adduction Measured?

Biomechanical assessments can quantify knee abduction/adduction angles during running. These analysis can be performed:

1. In lab:
   • With 3D motion capture systems: Considered the gold standard for measuring joint kinematics.
   • With wearable sensors: Inertial measurement units (IMUs) track knee angles dynamically.

Figure 3: Biomechanics lab illustration

1. With a clinician:
   • With video analysis: Clinicians and coaches often use slow-motion footage to evaluate knee alignment.

Figure 4: Clinician consultation illustration

1. By yourself:
   • With markerless motion analysis: AI-powered video analysis tools like Ochy provide biomechanics analysis by allowing runners to identify their movement patterns using just a smartphone. Learn more at Ochy’s website.

Figure 5: Ochy running analysis illustration

How Can Runners Prevent Knee Injuries?

1. Strength Training

• Hip and Core Strengthening: A 6-week hip strengthening program led to a 10% decrease in knee abductor moment during running (Snyder et al., 2009).
• Stability Training: An 8-week program incorporating lower extremity alignment awareness reduced hip and knee abductor moments by 15% and 23%, respectively (Earl & Hoch, 2011).
• Weight bearing exercises with visual, verbal, and tactile feedback: A 4-week movement training program reduced frontal plane knee and hip mechanics linked to running injuries (Wouters et al., 2012). After training, runners demonstrated a 1.8° decrease in peak knee abduction angle (Wouters et al., 2012).

You can find many of these exercices within the Ochy app which provides a strength training based on your running analysis: https://app.ochy.io/

2. Cadence Adaptation

• Increasing running cadence can reduce knee valgus angles, making it a simple and effective intervention (Peterson et al., 2024).

You can know your running cadence on the metrics proposed on the Ochy app (on the side view analysis): https://app.ochy.io/

3. Neuromuscular Training

• Plyometric exercises and neuromuscular drills can enhance lower limb stability, reducing excessive knee abduction forces (Letafatkar et al. 2020).

Figure 6: Example of plyometric exercise.

4. Pilates and Flexibility Work

• Pilates mat-based exercises have been shown to improve knee valgus after 12 weeks (Gonzales & Ortiz, 2023).

Conclusion

Knee abduction and adduction play a crucial role in running biomechanics and injury risk. While excessive knee abduction is linked to injuries like PFP and ACL tears, strengthening, and cadence adjustments can help mitigate these risks. Understanding how to assess and correct knee mechanics can empower runners to improve performance and reduce injury rates.

For an easy way to analyze and optimize your running form, consider using Ochy, an AI-powered video analysis app that provides running biomechanics analysis and muscles-strengthening exercices. Visit Ochy's website to learn more.

References

• Baker, Robert L., Richard B. Souza, Mitchell J. Rauh, Michael Fredericson, and Michael D. Rosenthal. 2018. ‘Differences in Knee and Hip Adduction and Hip Muscle Activation in Runners With and Without Iliotibial Band Syndrome’. PM & R: The Journal of Injury, Function, and Rehabilitation 10 (10): 1032–39. https://doi.org/10.1016/j.pmrj.2018.04.004.
• Earl, Jennifer E., and Anne Z. Hoch. 2011. ‘A Proximal Strengthening Program Improves Pain, Function, and Biomechanics in Women with Patellofemoral Pain Syndrome’. The American Journal of Sports Medicine 39 (1): 154–63. https://doi.org/10.1177/0363546510379967.
• Elias, John J., Jennifer A. Cech, David M. Weinstein, and Andrew J. Cosgrea. 2004. ‘Reducing the Lateral Force Acting on the Patella Does Not Consistently Decrease Patellofemoral Pressures’. The American Journal of Sports Medicine 32 (5): 1202–8. https://doi.org/10.1177/0363546503262167.
• Ferber, Reed, and Shari Macdonald. 2014. Running Mechanics and Gait Analysis. Champaign, IL: Human Kinetics. https://doi.org/10.5040/9781718209732.
• González, Jaime, and Alexis Ortiz. 2023. ‘Impact of Pilates Mat-Based Exercises on Knee Kinematics during Running’. Journal of Bodywork and Movement Therapies 33 (January):8–13. https://doi.org/10.1016/j.jbmt.2022.09.005.
• Hewett, Timothy E., Gregory D. Myer, Kevin R. Ford, Robert S. Heidt, Angelo J. Colosimo, Scott G. McLean, Antonie J. van den Bogert, Mark V. Paterno, and Paul Succop. 2005. ‘Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study’. The American Journal of Sports Medicine 33 (4): 492–501. https://doi.org/10.1177/0363546504269591.
• Huberti, H. H., and W. C. Hayes. 1984. ‘Patellofemoral Contact Pressures. The Influence of q-Angle and Tendofemoral Contact’. The Journal of Bone and Joint Surgery. American Volume 66 (5): 715–24.
• Letafatkar, Amir, Pouya Rabiei, and Mina Afshari. 2020. ‘Effect of Neuromuscular Training Augmented with Knee Valgus Control Instructions on Lower Limb Biomechanics of Male Runners’. Physical Therapy in Sport 43 (May):89–99. https://doi.org/10.1016/j.ptsp.2020.02.009.
• Noehren, Brian, Anne Schmitz, Ross Hempel, Carolyn Westlake, and William Black. 2014. ‘Assessment of Strength, Flexibility, and Running Mechanics in Men With Iliotibial Band Syndrome’. Journal of Orthopaedic & Sports Physical Therapy 44 (3): 217–22. https://doi.org/10.2519/jospt.2014.4991.
• Perry, Jacquelin, and Judith M. Burnfield. 2010. Gait Analysis: Normal and Pathological Function, Second Edition. 2nd ed. Thorofare: SLACK, Incorporated.
• Peterson, Jacob R., Collin R. Sanders, Nathan S. Reynolds, Conner A. Alford, Michael J. Platt, Jeffrey J. Parr, Felix Twum, James R. Burns, and David R. Dolbow. 2024. ‘Running Cadence and the Influence on Frontal Plane Knee Deviations’. Clinics and Practice 14 (6): 2491–98. https://doi.org/10.3390/clinpract14060195.
• Powers, Christopher M. 2003. ‘The Influence of Altered Lower-Extremity Kinematics on Patellofemoral Joint Dysfunction: A Theoretical Perspective’. The Journal of Orthopaedic and Sports Physical Therapy 33 (11): 639–46. https://doi.org/10.2519/jospt.2003.33.11.639.
• Sakaguchi, Masanori, Haruna Ogawa, Norifumi Shimizu, Hiroaki Kanehisa, Toshimasa Yanai, and Yasuo Kawakami. 2014. ‘Gender Differences in Hip and Ankle Joint Kinematics on Knee Abduction during Running’. European Journal of Sport Science 14 (S1): S302–9. https://doi.org/10.1080/17461391.2012.693953.
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• Wouters, Isaac, Thomas Almonroeder, Bryan DeJarlais, Andrew Laack, John D. Willson, and Thomas W. Kernozek. 2012. ‘Effects of a Movement Training Program on Hip and Knee Joint Frontal Plane Running Mechanics’. International Journal of Sports Physical Therapy 7 (6): 637–46.

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