This is an excerpt from Running Mechanics and Gait Analysis by Reed Ferber & Shari Macdonald.
Now that we have discussed many interrelationships among various clinical and biomechanical factors, we hope you are gaining an appreciation for the complexity of comprehensive analysis of the entire lower extremity. In an attempt to simplify the process of establishing these interrelationships, this chapter provides several tables that show how these factors relate to one another. We call the collection of tables our road map because we constantly refer to them to help guide us through interpreting and understanding our patients and their associated pathomechanics.
We have chosen to use observable or measurable biomechanical factors as the frame of reference to help guide and assist in musculoskeletal injury assessment. Moreover, the anatomical alignment, strength, and flexibility factors discussed directly relate to those in earlier chapters. If, for example, we do not list any flexibility factors, it is because there is no literature to validate its relationship to the biomechanical variables discussed. For other variables, such as peak knee flexion, there are no anatomical alignment factors related which we can discuss. This is either because there is little or no research or because we consider it to be a nonfactor in determining the overall movement pattern. First, we start with the foot and move up the kinematic chain.
Foot, Ankle, and Tibia
For the foot, ankle, and tibia, we have listed those structural, strength, and flexibility factors we discussed in the previous chapters. These are grouped into tables by biomechanical pattern. Not all factors listed in the right-hand column will be present for any given person with that atypical movement pattern. Excessive and reduced peak rearfoot eversion are listed as both being associated with injury. Excessive peak eversion velocity and excessive time to peak rearfoot eversion are also listed, but we do not discuss reduced eversion velocity or reduced (early) time to peak eversion as there is nothing in the scientific literature. We do not consider a low eversion velocity movement to be potentially injurious either. Finally, we've listed those factors associated with excessive and reduced peak tibial internal rotation, and it should become clear how proximal biomechanical factors are associated with these motions.