The US women’s national soccer team is the most successful in international women’s soccer. The team has won three Women’s World Cup titles, four Olympic gold medals, eight CONCACAF Gold Cups and 10 Algarve Cups. On Friday, June 28th, the US team will face France in the semi-finals in what is expected to be one of the most exciting games of the tournament. But as with any high intensity sport, injuries are an inevitable part of any game.
The NCAA reports that 65.3% of women’s soccer injuries are to the lower limb (based on data from the 2004-2005 and 2008-2009 seasons). Roth et al in the 2018 American Journal of Orthopedics reports that soccer injuries to the knee continue to rise. In this video blog, I will be reviewing some important assessment tools regarding the arthrokinematic assessment of the knee.
The knee is a complex compound modified hinge synovial joint. The term complex implies it has menisci. Compound infers there are multiple joint articulations within one joint capsule (the patellofemoral joint, medial tibiofemoral compartment and lateral tibiofemoral compartment). Modified hinge, also called modified ovoid, describes its shape. Synovial implies it has a joint capsule connecting the bones together and contains synovial fluid and hyaline cartilage.
The knee primarily moves in one plane, flexion and extension, about an axis in the frontal plane. However, when the knee is flexed it also has internal and external rotation, which moves about a longitudinal axis along the length of the bone.
The screw home mechanism is a well-known biomechanical event, which happens in the last 20 degrees of extension. The tibial surface, deepened by the medial and lateral meniscus, is concave and thus moves anteriorly in the same direction as the osteokinematic extension. The length of the articulating surface of the medial femoral condyle is longer than the lateral condyle. Therefore, the medial tibiofemoral compartment completes its anterior arthrokinematic glide before the lateral compartment. The lateral component continues its anterior arthrokinematic glide, creating an external rotation of the of the tibiofemoral joint. This essentially locks the knee into a closed pack/ stable position.
The menisci of the knee are able to slightly glide on the tibial plateau. They are bound to the tibial via the meniscotibial ligament, also called the coronary ligament. The meniscus and coronary ligaments can become damaged via torsional trauma. Resulting scar tissue, fibrosis and alterations in muscle recruitment patterns can interfere with the optimal knee axis of rotation. Alterations in the axis of rotation can result in undue stress and non-optimal loading of the knee.
Appreciation of the arthrokinematic movement of both medial and lateral compartments of the knee throughout its full range of motion is essential to understanding the biomechanics of knee and potential impairments, which can perpetuate pain and disability.
For further evaluation and treatment details, please watch my video below.
Roth TS, Osbahr DC. Knee Injuries in Elite Level Soccer Players. Am J Orthop (Belle Mead NJ). 2018 Oct; 47(10). Doi: 10.12788/ajo. 2018. 0088
Gibbon A. Knee Anatomy. North Yorkshire Orthopedic Specialists. Archived from the original April 2013.
Moore K, Dalley A, Agur A. (2006). Clinically Oriented Anatomy. Lippincott Williams and Wilkins. ISBN 978-0-7817-3639-9.