Effect of taping the patella on concentric and eccentric torque and EMG of knee extensor and flexor muscles in patients with patellofemoral pain syndrome

The acute effect of patella taping on torque and electromyographic (EMG) activity in maximal voluntary concentric and eccentric action of the knee extensor and flexor muscles in patients with patellofemoral pain syndrome was studied in 48 patients (62 knees). The patients (28 female, 20 male) were tested concentrically and eccentrically on a Kin-Com dynamometer with simultaneous EMG recording with the patella untaped and medially or laterally taped. Patients with clinically normal patellar mobility did not improve their quadriceps performance by taping of the patella: after medial taping they decreased theur muscle torque during concentric work at 60°/s (P<0.05) and eccentric work at 180°/s (P<0.05). After lateral taping they decreased their muscle torque during concentric work at 60°/s (P<0.01), and 180°/s (P<0.05) and eccentric work at both 60°/s (P< 0.01) and 180°/s (P< 0.05). Moreover, these patients also decreased their agonist EMG activity during concentric work at 60°/s (P<0.05) and 180°/s (P<0.05) and their antagonist EMG activity during eccentric work at 60°/s (P<0.01). Patients with a clinical lateral patellar hypermobility increased their knee extensor torque after medial taping at 60°/s during both eccentric work (P<0.01) and concentric work (P<0.05). The greatest improvement in quadriceps performance, however, was in patients with a clinical medial patellar hypermobility. They increased their knee extensor torque after lateral taping during eccentric work at both 60°/s (P<0.001) and 180°/s (P<0.001) and during concentric work at 60°/s (P<0.001). They also increased agonist EMG activity during eccentric work at both 60°/s (P<0.01) and 180°/s (P<0.001) and during concentric work at 180°/s (P<0.05). Patients with both lateral and medial patellar hypermobility increased their knee extensor torque by patellar taping in either direction; after medial taping there was an increase during eccentric work at both 60°/s (P<0.01) and 180°/s (P<0.05) and after lateral taping they also showed an increase during eccentric work at 60°/s (P<0.01). There was a slight decrease in knee flexor torque with either medial or lateral taping in comparison with no taping. Furthermore, there was higher antagonist EMG activity during hamstring measurements when the patella was either medially or laterally taped as opposed to untaped. In all four groups of patients, except for the group with lateral and medial hypermobility, there was a highly significant correlation between patients' own evaluation of the taping and their patellar mobility according to the clinical examination.This study was supported by grants from the Swedish Sports Federation and from Beiersdorf Compancy, Homburg, Germany