title: Reliability study on quantitative detection of extensor digitorum brevis strength with needle electromyography and nerve conduction.
abstract: OBJECTIVE
  To study the objectivity and reliability of needle electromyography and nerve conduction for detection of musculus extensor digitorum brevis strength, which may provide a basis for establishing a quantitative detection of muscle strength in forensic clinical study.
  
  
  METHODS
  Forty-four healthy people were enrolled as the subjects, and during toe dorsiflexion, the following items including needle electromyography indexes, motor unit potential (MUP) amplitude, MUP count, recruitment reaction type, and nerve conduction detection indexes, compound muscle action potential (CMAP) amplitude, CMAP latent period and motor nerve conduction velocity (MNCV), were simultaneously detected under the cooperation and disguise condition.
  
  
  RESULTS
  Under the cooperation condition, regardless of the same operator or different operators, there were good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, while there were normal test-retest reliabilities in MUP count and recruitment reaction type and the repeatability of the same operator was slightly better than the repeatability between different operators. Under the disguise condition, test-retest reliabilities of MUP amplitude, CMAP amplitude, CMAP latent period and MNCV were relatively high, while test-retest reliabilities of MUP count and recruitment reaction type were relatively low.
  
  
  CONCLUSIONS
  There are good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, which can be conducive to comparison between different operators and results at various times; MUP count and recruitment reaction type, which can be easily affected by subjectivity of operators and examinees, can be used to differentiate whether an examinee disguises or not. The indexes used to objectively judge muscle strength remain to be further investigated.
authors.forename: Dong
authors.initials: D
authors.lastname: Gao
authors.forename: Qing
authors.initials: Q
authors.lastname: Xia
authors.forename: Dan
authors.initials: D
authors.lastname: Ran
authors.forename: Dong
authors.initials: D
authors.lastname: Tian
authors.forename: Guang-You
authors.initials: GY
authors.lastname: Zhu
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Fan
mesh_terms: D004567:Electrodes, Implanted; D004576:Electromyography; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation; D009431:Neural Conduction / Q000502:physiology*; D015203:Reproducibility of Results; D014034:Toes