ABSTRACT
Objective To observe the surface electromyography (sEMG) characteristics of upper limbs during one-finger pushing manipulation under different operating forces, so as to find out the muscle coordination movement pattern for key operating technology. Methods sEMG data of performing one-finger pushing manipulation by the expert, skilled and novice groups were collected. The manipulation force was divided into three different types, namely mild, moderate and severe. The continuous, stable data were adopted for analysis on Myo-Research software. Results Significant differences were found in the upper limb muscle integrated electromyography (iEMG) values (P0.05), with the flexor carpi ulnaris, deltoid, wrist flexors and extensors ranking the top three of iEMG ratio. The expert and skilled groups had the same core muscles in the same movement pattern during their manipulation operation, while the novice group had different core muscles under different forces. There were significant differences in co-contraction ratio among the expert, skilled and novice groups (P<0.01). The novice and expert groups had the highest and lowest co-contraction ratio, respectively, and the co-contraction ratio was gradually decreased with force increasing. During 6-minute manipulation operation, deltoid median frequency(MF) slope of the expert group was declined more slowly than that in the other two groups (P<0.05), which indicated that the expert group were better at resisting to fatigue. Conclusions The expert and skilled groups have the same sEMG characteristics during one-finger pushing manipulation operation with the same core muscles. The movement pattern of upper limb muscles is of regularity. The iEMG ratio, MF slope and co-contraction ratio can be used as reference standard for evaluating the durability, and homogeneity of the manipulation operation and normalization of force application.
ABSTRACT
@#Objective To observe the influence of dynamic contractions on the sEMG co-contraction ratio taken from the antagonist muscles of the knee joint of stroke patients.Methods 11 stroke patients and 14 healthy subjects were measured the dynamic contractions in both knee flexion and extension with the surface electromyography(sEMG).Results There was no significant differences of the median frequency(MF),mean power frequency(MPF),average EMG(AEMG)and the sEMG co-contraction ratio within the stroke patients and the healthy(P>0.05).There was no significant difference of the MF between the patients compared with the healthy(P>0.05),but the sEMG co-contraction ratio of the MPF increased significantly and that of AEMG decreased significantly(P<0.01).Conclusion The MPF,AEMG and the sEMG co-contraction ratio taken from the stoke patients may reflect the characters of the low limb muscle and the MF may not.