Faculty Members

Faculty of Sports and Health Sciences

Department of Sports and Health Sciences

Key words
Weight bearing index , Speed of sound , Gait speed , Physical function

Ph.D. / Professor

Takahiko Sakazaki


National Institute of Fitness and Sports in Kanoya, Faculty of Physical Education,
Nagoya University, Graduate School, Education and Human Development, Doctor Course Previous Term,
Nagoya University, Graduate School, Division of Medical Sciences, Doctor Course, Accomplished Credits for Doctoral Program

Professional Background

Sports Research Center , Otemon Gakuin University/Staff

Consultations, Lectures, and Collaborative Research Themes

Consultation about a lifestyle and the health, Experience of the Nordic walking, Measurement of the walking speed.

Main research themes and their characteristics

「Association between gait speed and bone strength in community-dwelling postmenopausal Japanese women」

 Gait speed is the most frequently used physical performance measurement, and an association between gait speed and survival in older adults has been reported . Likewise, slow walking speed in older people has been shown to be strongly associated with an increased risk of cardiovascular mortality.
 It is unclear whether gait speed can be used to predict bone status or to diagnose osteopenia or osteoporosis. Bone mineral density (BMD) is currently used to diagnose osteoporosis, and its decrease is the major risk factor for bone fracture. We measured heel bone density by ultrasound, as this measurement has been shown to predict the risk of hip fracture as efficiently as BMD measurement.
 We measured speed of sound (SOS), weight bearing index (WBI), maximum or usual gait speed, step length of each gait, single leg balance time with or without eyes closed, and grip strength among 1,061 postmenopausal women (mean age ± standard deviation 68 ± 8 years).
 After adjustments for age and body mass index, SOS was associated with maximum or usual gait speed and with step length during maximum speed gait, but not with WBI, grip strength, single-leg balance time with or without eyes closed, or step-length time during usual gait speed (Table 1). When subjects were divided into quartile groups based on WBI (a marker of lower extremity strength), significant associations between usual or maximum gait speed and SOS were found only in the lowest and second lowest groups (first and second quartiles). Finally, analysis of sensitivity and specificity at various cut-off points of maximum gait speed to predict decreased SOS showed relatively high specificity compared with the corresponding sensitivity among those with low gait speed.
 Receiver operating characteristic (ROC) curves for detecting persons with an SOS value of less than 1,501 or 1,479 m/s revealed better test performance using maximum gait speed (Fig. 1). Since the SOS of most of the subjects aged 85 years and older is less than 1,479 m/s, this group of subjects was excluded from this analysis. The sensitivity and specificity of predicting individuals with a SOS of less than 1,501 or 1,479 m/s showed a relatively high specificity among those with a low maximum gait speed (Fig. 2).
 In conclusion, the combination of WBI and gait speed is a specific method by which to screen subjects with low SOS values and, therefore, at high risk of bone fracture. It is currently not easy to clinically discriminate those individuals at high risk for critical fractures; therefore, gait speed and physical examination may become useful tools in clinical practice.

Major academic publications

Takahiko Sakazaki, Teruhiko Koike, Yuji Yanagimoto & Yoshiharu Oshida
“Association between gait speed and bone strength in community-dwelling postmenopausal Japanese women”
Environmental Health and Preventive Medicine,17 (2012) 394–400.

Takahiko SAKAZAKI, Masakazu KUBOTA & Yoshiharu OSHIDA
“An examination of the Integrated Curriculum of nursing training schools (in Japanese)”
Medical Education 2007;38(5):321-324.

Takahiko Sakazaki, Teruhiko Koike & Yoshiharu Oshida
“Proposal to implement salary system for Teaching Assistant in health professional education (in Japanese)”