title: Strengthening of Quadriceps by Neuromuscular Magnetic Stimulation in Healthy Subjects.
abstract: BACKGROUND
  Quadriceps muscle strengthening is one of the rehabilitation strategies for improving walking in some people with gait impairments, and neuromuscular electrical stimulation (NMES) has been used for that reason. The strengthening effect of neuromuscular magnetic stimulation (NMMS) on the quadriceps has been demonstrated in various conditions, but not specifically for gait training. The purpose of this study was to determine whether the effect of NMMS is clinically applicable.
  
  
  OBJECTIVE
  To determine the effect of NMMS on quadriceps muscle strength, cross-sectional area (CSA) and thickness in healthy subjects.
  
  
  METHODS
  Single-blind, prospective, case-control study.
  
  
  METHODS
  Tertiary academic hospital setting.
  
  
  METHODS
  A total of 40 healthy volunteers were randomly assigned to an NMMS (n = 20) or control group (n = 20).
  
  
  METHODS
  Fifteen minutes of quadriceps NMMS of at maximum tolerable intensity, 3 times per week for 5 weeks.
  
  
  METHODS
  At baseline and after the intervention, the CSA and thicknesses of the rectus femoris and vastus intermedius were measured by ultrasound. Isometric and isokinetic maximal and average peak torques of the dominant side knee extensors were also measured at pre- and postintervention.
  
  
  RESULTS
  There were no between-group differences in strength, CSA, or muscle thickness at baseline. Isometric maximum and average peak torque of NMMS group were increased significantly after 5 weeks of intervention (P < .001). The isokinetic maximum and average peak torque of NMMS group were increased significantly at both angle velocities of 60°/sec and 120°/sec after 5 weeks of intervention (P < .001). However, neither group showed a significant difference in cross-sectional area or thickness after training.
  
  
  CONCLUSIONS
  NMMS can be a useful strengthening method for large skeletal muscles such as the quadriceps.
  
  
  METHODS
  II.
authors.affiliation: Daejeon Chungcheong Regional Rehabilitation Center, Chungnam National University Hospital, Daejeon, Republic of Korea(∗).
authors.forename: Shin-Seung
authors.initials: SS
authors.lastname: Yang
authors.affiliation: Daejeon Chungcheong Regional Rehabilitation Center, Chungnam National University Hospital, Daejeon, Republic of Korea(†).
authors.forename: Sungju
authors.initials: S
authors.lastname: Jee
authors.affiliation: Department of Rehabilitation Medicine, Daejeon Wellness Rehabilitation Hospital, Daejeon, Republic of Korea(‡).
authors.forename: Seon Lyul
authors.initials: SL
authors.lastname: Hwang
authors.affiliation: Department of Rehabilitation Medicine, School of Medicine, Chungnam National University, 266, Munhwa-ro, Jung-gu, Daejeon, Republic of Korea, 35015(§). Electronic address: mksohn@cnu.ac.kr.
authors.forename: Min Kyun
authors.initials: MK
authors.lastname: Sohn
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D064368:Healthy Volunteers; D006801:Humans; D008280:Magnetics; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging / Q000502:physiology*; D016037:Single-Blind Method; D062606:Tertiary Care Centers; D013997:Time Factors; D018608:Ultrasonography, Doppler / Q000379:methods