Interactions among LE joints
Postures (or movements) at one joint, whether they are structural or functional, require complementary postures at adjacent joints, especially during activities that occur in a closed kinematic chain. Thus, a fault in one joint or segment can lead to problems in nearby joints or segments.
- Excessive subtalar pronation during early stance.
Review normal subtalar movement
Effect on foot and knee arthrokinematics when early stance pronation is excessive:
- Push-off occurs on a relatively mobile foot
- The q-angle changes during the gait cycle, with possible effects on patellofemoral mechanics (Hertling & Kessler, 1996, pp.355-357).
- Pronation may necessitate a compensatory internal femoral rotation (Tiberio, 1987) to preserve normal arthrokinematics at the knee. This theoreticial compensation may increase lateral patellar pressure.
- Femoral anteversion and antetorsion
Both anteversion and antetorsion are transverse plane measures (Hertling & Kessler, 1996, pp.286-287).
Typical angles for both measures are 15 degrees. Antetorsion is measured clinically by Ryder's test (Cusick & Stuberg, 1992).
Anteversion is an angular measurement that relates the femoral neck's position or posture to the frontal plane. The figure (Wheeless, 1996) illustrates the anteversion angle.
Antetorsion relates the femoral neck's angular orientation to a line that connects the femoral condyles (Hertling & Kessler, 1996, Fig 12-3, p. 286). As such, it describes a bony or structural torsion or twisting of the femoral shaft.
Compensations (Hertling & Kessler, p.322) must occur when the measures are unequal.
Cusick, B.D., & Stuberg, W.A. (1992). Assessment of lower-extremity alignment in the transverse plane: Implications for management of children with neuromotor dysfunction. Physical Therapy, 72, 3-15.
Hertling, D., & Kessler, R. M. (1996). Management of common musculoskeletal disorders: Physical therapy principles and methods. (3rd ed.). Philadelphia: J.B. Lippincott.
Tiberio, D. (1987). The effect of excessive subtalar joint pronation on patellofemoral mechanics: A theoretical model. Journal of Orthopedic and Sports Physical Therapy, 9, 160-169.
Wheeless, C.R. (1996). Rotational alignment of femoral shaft fractures. Wheeless' Textbook of Orthopaedics [On-line]. Available: http://medmedia.com/oo4/1640.htm.