Yoshida S1, Kanzaki H2
1Graduate School of Yamagata Prefectural University of Health Sciences, Physical Therapy, Yamagata, Japan, 2Yamagata Prefectural University of Health Sciences, Physical Therapy, Yamagata, Japan
Background: Standing and sitting motions before and after walking are fundamentally important for activities of daily living. Masai Barefoot Technology (MBT) footwear, among unstable footwear, is constructed with a shock-absorbing cushioned heel and a rounded sole in the anterior-posterior direction has large curves of the soles. Reportedly, MBT footwear improves walking posture and reduces lower limb joint motion and loading. Nevertheless, the actual effects of wearing MBT on lower limb kinematics and muscle activities during standing and sitting remain unclear.
Purpose: To examine the effects of wearing MBT footwear on joint kinematics and muscle activities of the lower limb during standing up and sitting down.
Methods: Eighteen young adults (20-22 years) with no history of major lower limb injury participated. They were asked to stand up from a chair and sit down in the following three conditions: without footwear (barefoot), with flat-bottomed footwear, and with MBT footwear. Kinematic and kinetic data were collected simultaneously using a three-dimensional motion analysis system (Vicon Motion Systems), two force plates (Kistler Instruments AG), and electromyography (Delsys Inc.). The seat length was 60% of the thigh length. The seat height was set as the lower leg length, with 1 cm added when wearing flat-bottomed footwear and 2 cm added when wearing MBT footwear. The seat-off (buttock leaves the seat) timing was defined as the moment when the floor reaction force value in the vertical direction becomes the maximum. Data were compared by repeated measures analysis of variance. Statistical significance was inferred for values of p 0.05.
Results: By wearing MBT footwear during a standing motion, the ankle dorsiflexion angle before and after seat-off, the knee flexion angle and plantar flexor activity after seat-off were increased significantly when compared with other conditions. In sitting motion, the anterior-posterior width of COP was decreased and the ankle dorsiflexion angle, knee flexion angle and dorsiflexor activity were increased considerably. No significant differences were found between a barefoot condition and wearing flat-bottomed footwear condition for any parameter.
Conclusion(s): Results demonstrate that wearing MBT footwear mainly effects ankle joint and lower leg muscle activity during standing up and sitting down: by wearing MBT shoes when standing and sitting motions, greater motion of the ankle joint, and greater muscle activity of the lower leg muscle are required. Future research for elderly people must examine movements and muscle activity of the proximal joint by the kinematic chain of the ankle.
Implications: Results of this study provide important information related to standing and sitting mechanisms while wearing MBT footwear. These results indicate that standing requires more dorsiflexion angle and plantar flexor force. Sitting also requires more dorsiflexion angle and dorsiflexor force for MBT than for either barefoot or flat-bottomed footwear. Therefore, assessing the adaptation of MBT footwear from lower leg muscle strength and the range of the ankle joint angle is necessary.
Keywords: biomechanics, Masai Barefoot Technology footwear, motion analysis
Funding acknowledgements: None
Purpose: To examine the effects of wearing MBT footwear on joint kinematics and muscle activities of the lower limb during standing up and sitting down.
Methods: Eighteen young adults (20-22 years) with no history of major lower limb injury participated. They were asked to stand up from a chair and sit down in the following three conditions: without footwear (barefoot), with flat-bottomed footwear, and with MBT footwear. Kinematic and kinetic data were collected simultaneously using a three-dimensional motion analysis system (Vicon Motion Systems), two force plates (Kistler Instruments AG), and electromyography (Delsys Inc.). The seat length was 60% of the thigh length. The seat height was set as the lower leg length, with 1 cm added when wearing flat-bottomed footwear and 2 cm added when wearing MBT footwear. The seat-off (buttock leaves the seat) timing was defined as the moment when the floor reaction force value in the vertical direction becomes the maximum. Data were compared by repeated measures analysis of variance. Statistical significance was inferred for values of p 0.05.
Results: By wearing MBT footwear during a standing motion, the ankle dorsiflexion angle before and after seat-off, the knee flexion angle and plantar flexor activity after seat-off were increased significantly when compared with other conditions. In sitting motion, the anterior-posterior width of COP was decreased and the ankle dorsiflexion angle, knee flexion angle and dorsiflexor activity were increased considerably. No significant differences were found between a barefoot condition and wearing flat-bottomed footwear condition for any parameter.
Conclusion(s): Results demonstrate that wearing MBT footwear mainly effects ankle joint and lower leg muscle activity during standing up and sitting down: by wearing MBT shoes when standing and sitting motions, greater motion of the ankle joint, and greater muscle activity of the lower leg muscle are required. Future research for elderly people must examine movements and muscle activity of the proximal joint by the kinematic chain of the ankle.
Implications: Results of this study provide important information related to standing and sitting mechanisms while wearing MBT footwear. These results indicate that standing requires more dorsiflexion angle and plantar flexor force. Sitting also requires more dorsiflexion angle and dorsiflexor force for MBT than for either barefoot or flat-bottomed footwear. Therefore, assessing the adaptation of MBT footwear from lower leg muscle strength and the range of the ankle joint angle is necessary.
Keywords: biomechanics, Masai Barefoot Technology footwear, motion analysis
Funding acknowledgements: None
Topic: Human movement analysis; Musculoskeletal: lower limb; Orthopaedics
Ethics approval required: No
Institution: Yamagata Prefectural University of Health Sciences
Ethics committee: The ethical board of Yamagata Prefectural University of Health Sciences
Reason not required: This research was conducted at the class (Physical Therapy Graduation thesis) in Yamagata Prefectural University of Health Sciences. At our university graduation research, currently, non-invasive research for students like our research can be carried out without obtaining approval from the ethics committee. Before experiments, we explained the contents of the research and received written consent from all participants.
All authors, affiliations and abstracts have been published as submitted.
