title: Influence of spinal sagittal alignment, body balance, muscle strength, and physical ability on falling of middle-aged and elderly males.
abstract: OBJECTIVE
  Risk factors for falling in elderly people remain uncertain, and the effects of spinal factors and physical ability on body balance and falling have not been examined. The objective of this study was to investigate how factors such as spinal sagittal alignment, spinal range of motion, body balance, muscle strength, and gait speed influence falling in the prospective cohort study.
  
  
  METHODS
  The subjects were 100 males who underwent a basic health checkup. Balance, SpinalMouse(®) data, grip strength, back muscle strength, 10-m gait time, lumbar lateral standing radiographs, body mass index, and fall history over the previous year were examined. Platform measurements of balance included the distance of movement of the center of pressure (COP) per second (LNG/TIME), the envelopment area traced by movement of the COP (E AREA), and the LNG/E AREA ratio. The thoracic/lumbar angle ratio (T/L ratio) and sagittal vertical axis (SVA) were used as an index of sagittal balance.
  
  
  RESULTS
  LNG/TIME and E AREA showed significant positive correlations with age, T/L ratio, SVA, and 10-m gait time; and significant negative correlations with lumbar lordosis angle, sacral inclination angle, grip strength and back muscle strength. Multiple regression analysis showed significant differences for LNG/TIME and E AREA with T/L ratio, SVA, lumbar lordosis angle and sacral inclination angle (R (2) = 0.399). Twelve subjects (12 %) had experienced a fall over the past year. Age, T/L ratio, SVA, lumbar lordosis angle, sacral inclination angle, grip strength, back muscle strength, 10-m gait time, height of the intervertebral disc, osteophyte formation in radiographs and LNG/E AREA differed significantly between fallers and non-fallers. The group with SVA > 40 mm (n = 18) had a significant higher number of subjects with a single fall (6 single fallers/18: p = 0.0075) and with multiple falls (4 multiple fallers/18: p = 0.0095).
  
  
  CONCLUSIONS
  Good spinal sagittal alignment, muscle strength and 10-m gait speed improve body balance and reduce the risk of fall. Muscle strength and physical ability are also important for spinal sagittal alignment. Body balance training, improvement of physical abilities including muscle training, and maintenance of spinal sagittal alignment can lead to prevention of fall.
authors: Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, 65, Tsurumai, Showa-ku, Nagoya, Aichi, 466-8550, Japan. imagama@med.nagoya-u.ac.jp
authors: Shiro
authors: S
authors: Imagama
authors: Zenya
authors: Z
authors: Ito
authors: Norimitsu
authors: N
authors: Wakao
authors: Taisuke
authors: T
authors: Seki
authors: Kenichi
authors: K
authors: Hirano
authors: Akio
authors: A
authors: Muramoto
authors: Yoshihito
authors: Y
authors: Sakai
authors: Yukihiro
authors: Y
authors: Matsuyama
authors: Nobuyuki
authors: N
authors: Hamajima
authors: Naoki
authors: N
authors: Ishiguro
authors: Yukiharu
authors: Y
authors: Hasegawa
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012307:Risk Factors; D013131:Spine / Q000502:physiology*