[The role of the quadriceps muscle for the patello-femoral malalignment syndrome].
At knee extension on the Cybex Machine II (Lumex, Co. Ltd.), electromyograms (EMG) from the vastus medialis (M) and the vastus lateralis (L) were picked up by surface electrodes. The L/M ratio was calculated by the integrated value of the EMG and the power spectrum dealt with the frequency analysis of the EMG. There was a correlation between the L/M ratio and Q angle for the normal group, a constant relation for the hypermobile patella group, and an inverse correlation for the group with recurrent subluxation of patella. The vastus medialis (M)-dominant group, intermediate group and the vastus lateralis (L)-dominant group from the value of the L/M ratio was also classified. In the control group, subgroup 2 with clinical signs or their past histories around the knee included relatively more L-dominant than subgroup 1 without clinical signs. In the patello-femoral malalignment group, more cases were L-dominant.
Department of Orthopaedic Surgery, Jichi Medical School, Tochigi, Japan.
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Suzuki
D001696:Biomechanical Phenomena; D004576:Electromyography; D006621:Hip Joint; D006801:Humans; D004204:Joint Dislocations / Q000503:physiopathology*; D007593:Joint Instability / Q000503:physiopathology*; D007718:Knee Injuries / Q000503:physiopathology*; D009132:Muscles / Q000503:physiopathology*; D010329:Patella / Q000293:injuries*