Those familiar with implementation of repeated motions are likely familiar with the benefit of using tibial internal rotation (IR) to improve lower quarter dysfunction. However, the majority of clinicians associate press-ups with repeated motions and are unaware of how to use the technique with the extremities. Each joint has a "common reset" that can be used to improve both pain and mobility. These patterns are based on common dysfuntional presentations but are by no means a rule. While the majority of injuries will respond to some sore of repeated motion, it may take time and there are some occasions where a joint may not respond.
One of the common resets for the knee is tibial IR. As many of you are aware, the arthrokinematics of the knee include tibial rotation during sagittal plane motion. As the knee extends, there is a slight ER of the tibia that occurs to help lock it out. As the knee flexes, the tibial slightly internally rotates. When injury occurs to the knee, we often see a loss of one of these rotation motions as either end-range knee flexion or extension is affected. Thus, the repeated motion for limited tibial IR is closed-kinetic chain (CKC) knee flexion repeatedly while manual overpressure is applied into IR.
While this exercise is obviously beneficial for knee disorders, it can also be implemented with foot/ankle dysfunction. Limited CKC ankle DF has been shown to be associated with excessive tibial external rotation (Rabin et al, 2016). This likely being associated with limited tibial IR mobility. Utilizing this same exercise (or something that similarly addresses decreased tibial IR) for limited ankle DF ROM can improve functional CKC mobility. Part of the reason for this benefit may be due to abnormal foot/ankle movement patterns. For example, take a look at an excessively prontated foot. As this ankle moves into DF, the motion prefers to come from the talonavicular joint or somewhere distal. This pattern leads to an abnormal utilization of tibial internal rotation at the knee. By maintaining subtalar neutral while moving into CKC DF with tibial IR overpressure, we may theoreticlly be mobilizing part of the talocrural capsule that is typically restricted and forcing a prontation motion. With the association shown between limited ankle DF mobility and hip/knee problems, it is well worth examination in all lower quarter patients. Try checking your patients ankle DF mobility in CKC for the next couple weeks and look for any abnormal movement patterns. See if you start to notice some patterns.
-Dr. Chris Fox, PT, DPT, OCS
Rabin A, Portnoy S, Kozol Z. (2016). The Association of Ankle Dorsiflexion Range of Motion With Hip and Knee Kinematics During the Lateral Step-down Test. J Orthop Sports Phys Ther. 2016 Nov;46(11):1002-1009.