title: Electromyographic analysis of training to selectively strengthen the lumbar multifidus muscle: effects of different lifting directions and weight loading of the extremities during quadruped upper and lower extremity lifts.
abstract: OBJECTIVE
  The lumbar multifidus muscle (LMF) is a lower back muscle that contributes to spinal stability. Several electromyographic analyses have evaluated LMF activity during various types of training. The present study examined the activity of the back muscles during quadruped upper and lower extremity lifts (QULELs) with different lifting direction and weight loading of extremities.
  
  
  METHODS
  Seventeen healthy men were included as subjects. The exercise conditions comprised raising the upper extremity of one side and the lower extremity of the opposite side in a quadruped position with different lifting direction and weight loading. The various combinations of lifts were modifications of conventional QULEL, in which the upper extremity is raised to 180° shoulder flexion and the lower extremity to 0° hip extension. The effects of different lifting directions and weight loading on LMF and lumbar erector spinae (LES) muscle activities were measured using surface electromyography.
  
  
  RESULTS
  The LMF activity and the LMF/LES activity ratio on the side of lower extremity lifting were higher during QULEL with the upper and lower extremities in abduction than during conventional QULEL. The LMF/LES activity ratio was lower during QULEL with weight loading on the upper and lower extremities than during conventional QULEL.
  
  
  CONCLUSIONS
  The results of the present study suggest that QULEL with shoulder and hip abduction is more effective to selectively strengthen LMF on the side, where the lower extremity is lifted. Loading weight onto both the lifted upper and lower extremities during QULEL is disadvantageous as a selective LMF training method because the LMF/LES activity ratio is low.
authors.affiliation: PhD Course Student, Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address: masaki.mitsuhiro.27w@st.kyoto-u.ac.jp.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Masaki
authors.affiliation: Assistant Professor, Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Tateuchi
authors.affiliation: Associate Professor, Department of Physical Therapy, Faculty of Rehabilitation, Hyogo University of Health Sciences, Kobe, Japan.
authors.forename: Rui
authors.initials: R
authors.lastname: Tsukagoshi
authors.affiliation: Research Assistant, Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Ibuki
authors.affiliation: Professor, Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ichihashi
mesh_terms: D004576:Electromyography / Q000379:methods*; D064368:Healthy Volunteers; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008159:Lumbar Vertebrae; D008161:Lumbosacral Region; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D064170:Paraspinal Muscles / Q000502:physiology*; D012016:Reference Values; D034941:Upper Extremity / Q000502:physiology; D014891:Weight Lifting / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology; D055815:Young Adult
keywords: Electromyography; Exercise Therapy; Paraspinal Muscles