title: Correlation between muscle electrophysiology and strength after fibular nerve injury.
abstract: Muscle strength measurement is important when evaluating the degree of impairment in patients with nerve injury. However, accurate and objective evaluation may be difficult in patients with severe pain or those who intentionally try to avoid full exertion. We investigated the usefulness of the affected-to-unaffected side electrophysiological parameter ratios as a measure of objective ankle dorsiflexion (ADF) strength in patients with unilateral fibular nerve injury (FNI). ADF strength was measured in patients with FNI via handheld dynamometer and manual muscle test (MMT). Fibular nerve compound muscle action potential (CMAP) amplitude and latency and ADF strength of the affected side were presented as ratios to the corresponding measurements of the unaffected side. We analysed the correlation of the CMAP ratio with the ADF strength ratio using a dynamometer and compared the CMAP ratios according to MMT grade. Fifty-two patients with FNI were enrolled. The mean CMAP latency ratio did not differ between MMT groups (p = 0.573). The CMAP amplitude ratio proportionally increased with the quantified ADF strength ratio via dynamometer increase (ρ = 0.790; p < 0.001), but the CMAP latency ratio and the quantified ADF strength ratio did not significantly correlate (ρ = 0.052; p = 0.713). The average CMAP amplitude ratio significantly differed between MMT groups (p < 0.001), and post hoc tests showed significant differences in all paired comparisons except of Fair and Good grades (p = 0.064). Electrophysiological parameter ratio, such as the affected-to-unaffected side CMAP amplitude ratio, might be sensitive parameters for ADF power estimation after FNI.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Yu Hui
authors.initials: YH
authors.lastname: Won
authors.affiliation: Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Kang-Won
authors.initials: KW
authors.lastname: Kim
authors.affiliation: Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Jun Tak
authors.initials: JT
authors.lastname: Choi
authors.affiliation: Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Myoung-Hwan
authors.initials: MH
authors.lastname: Ko
authors.affiliation: Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Park
authors.affiliation: Chonbuk National University Medical School and Hospital, 634-18, Keumam-dong, Dukjin-gu, Jeonju, 561-712, Republic of Korea. vivaseo@jbnu.ac.kr.
authors.forename: Jeong-Hwan
authors.initials: JH
authors.lastname: Seo
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D000368:Aged; D000842:Ankle / Q000503:physiopathology; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology*; D020427:Peroneal Neuropathies / Q000473:pathology* / Q000503:physiopathology*; D012018:Reflex / Q000502:physiology
keywords: Compound muscle action potential; Electrophysiological parameters; Fibular nerve injury; Manual muscle test; Muscle strength