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M. Kuroda1, T. Jiromaru2, M. Ikeya2, M. Wachi2, S. Noguchi2,3, Y. Hyodo1,3, N. Kanazawa2
1Kanazawa Orthopedic & Sports Medicine Clinic, Ritto, Japan, 2Biwako Professinal University of Rehabilitation, Physical Therapy, Higashiomi, Japan, 3Kyoto Institute of Technology, Kyoto, Japan
Background: The deterioration of gait ability caused by physical dysfunction can lead to falls or dementia. The gait speed, one of the index of gait ability is easy to measure in clinical settings and is an effective indicator to confirm the physical fitness of elderly people (Furuna et al. 1998). The stride and cadence determine gait speed. Reduced stride length is a better predictive factor of increased risk of falling and dementia than cadence (Guimaraes et al. 1980; Taniguchi. 2013). Therefore, it is vital to maintain and prolong stride length. Previous studies have reported a relationship between leg muscle strength and stride length (Judge et al. 1996; Sipila et al. 1996; Requiao et al. 2005), indicating the association of shorter stride length with ageing. However, the correlation between trunk muscle strength and stride length are still unclear.
Purpose: In the current study, we aimed to clarify the relationship between gait ability and trunk muscle strength focusing on stride length and trunk muscle strength.
Methods: The study included 12 frail elderly participants (four male, eight female) who required support in their daily living. The mean age was 83.4±0.5 years. They could walk independently or using some walking aid. The measurement items included the two-step test, gait with free speed (5 m), and with maximum speed (5 m).
Due to difficulties in accurate measurement of trunk muscle strength in elderly people, the ventilatory muscles were used as an evaluation item. Because the diaphragm and external intercostal muscles contract in forced inspiration, and transverse abdominals, internal oblique abdominals, external oblique abdominals, rectus abdominals, and internal intercostal muscles are active in forced exhalation. The maximum stride length was measured as the participants made two steps forward as far as possible (two-step test). The inspiratory and expiratory muscle strength were measured using a respiratory muscle strength measuring Device (Autospiro AS-507; MINATO, Japan). To analyse the relationship between the gait ability with free speed gait, maximum speed gait and maximum stride length, and the ventilatory muscle strength: inspiratory and expiratory muscles, Spearman correlation coefficient was performed using SPSS (version 21.0). The level of significance was set at p < 0.05.
Due to difficulties in accurate measurement of trunk muscle strength in elderly people, the ventilatory muscles were used as an evaluation item. Because the diaphragm and external intercostal muscles contract in forced inspiration, and transverse abdominals, internal oblique abdominals, external oblique abdominals, rectus abdominals, and internal intercostal muscles are active in forced exhalation. The maximum stride length was measured as the participants made two steps forward as far as possible (two-step test). The inspiratory and expiratory muscle strength were measured using a respiratory muscle strength measuring Device (Autospiro AS-507; MINATO, Japan). To analyse the relationship between the gait ability with free speed gait, maximum speed gait and maximum stride length, and the ventilatory muscle strength: inspiratory and expiratory muscles, Spearman correlation coefficient was performed using SPSS (version 21.0). The level of significance was set at p < 0.05.
Results: A positive correlation was found between the maximum stride length and expiratory muscle strength (r=0.734, p<0.05). A negative correlation was shown between free speed gait and expiratory muscle strength (r=-0.692, p<0.05) and maximum speed gait and expiratory muscle strength (r=-0.683, p<0.05). There was no significant correlation between gait ability and inspiratory muscle strength.
Conclusion(s): This study revealed that expiratory muscle strength relates to the stride length in frail elderly people. Furthermore, the strength of these expiratory muscles affects gait speed.
Implications: These findings can contribute to the establishment of an effective trunk muscle training regime to prevent falling and dementia in frail elderly people.
Funding, acknowledgements: Nothing
Keywords: ventilatory muscle training, Inspiratory muscle, expiratory muscle
Topic: Older people
Did this work require ethics approval? Yes
Institution: Kanazawa Orthopaedic & Sports Medicine Clinic
Committee: Ethics Review Board of Kanazawa Orthopaedic & Sports Medicine Clinic
Ethics number: Kanazawa-OSMC-2019-001
All authors, affiliations and abstracts have been published as submitted.
