KINEMATIC ANALYSIS OF GAIT WHILE USING A SMARTPHONE

¹Teikyo Heisei University, Physical Therapy, Tokyo, Japan

Background: Recently, smartphones have been deeply involved in people´s everyday lives. The Internet, games, your phone and other amazing application software are available everywhere using a smartphone. Many pedestrians use smartphones during their everyday walking routine. This frequently causes collisions, falls and other accidents. According to the Fire Department reports in Tokyo, 152 people had to be carried to the hospital by ambulance due to an accident involving walking while using a smartphone from 2010 to 2014. These unsafe situations are dangerous for people, especially the handicapped.

Purpose: The objective of this study was to clarify characteristics of walking using a smartphone from the view point of kinematic analysis.

Methods: We enrolled 9 healthy adult males (age: 22±0.7 years, height 170±6.8cm, weight 60.7±6.1kg) and 7 healthy adult females (age: 22.1±0.4 years, height 160.7±4.2cm, weight 54.1±6.6kg). The three dimensional motion analysis system (Vicon Nexus) was used for kinematic evaluations. 35 reflective markers were attached on the entire body on the Vicon Plug-in Gait Model, and the sampling frequency was 100Hz. The individuals walked barefoot through an approximately four-meter gait path in the laboratory. First they walked normally then they walked while using a smartphone. Instructions were given to each subject that gait speed should be maintained as normal and should not be intentionally changed. Speed, cadence and stride of their normal gaits and the gaits while using a smartphone were measured. Both the range of motions and the maximum height of toes were measured for the two methods of gait. This data was compared between the two methods of gait. Statistical analysis used the Wilcoxon signed-rank test with a 1% significance level.

Results: The following results were obtained. (figures expressed as median ±QD): 1) Speed of a gait while using a smartphone (0.94±0.07m/sec) was significantly slower than those of a normal gait (1.16±0.01 m/sec). Cadence of gait while reading using a smartphone (103.9±4.3step/min) was significantly lesser than that of the normal gait (112.2±5.3step/min). Stride of gait while using a smartphone (1.083±67.3mm) was significantly shorter than that of the normal gait (1.240±43.2mm). 2) For gait while using a smartphone, in spite of the upper extremities and the torso moving non-symmetrically, the lower extremities moved symmetrically. 3) The maximum height of toes during the swing phase of the gait while using a smartphone (98.6±3.8mm) was significantly lower than that of the normal gait (102.4±2.4mm).

Conclusion(s): When using a smartphone, gait speed was slower, cadence was lower and stride was shorter than each parameter of the normal gait. The maximum height of toes during the gait while using a smartphone was significantly lower than that of the normal gait. These results suggested that the gait while using a smartphone is not an effective method of locomotion.

Implications: This study suggested that the gait while using a smartphone is not recommended from the view point of kinematic experiments. ‘These results are available for smartphone user´s notice.

Funding acknowledgements: None applicable.

Topic: Human movement analysis

Ethics approval: The research was conducted with the approval of the Ethical Committee of Teikyo Heisei University (Approval No. 26-067).

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