Optimal foot-position of caregiver based on muscle activity of lower back and lower limb while providing sit-to-stand support

Abstract

[Purpose] In caregivers, low load posture is necessary to prevent lower back pain during patient handling activities such as sit-to-stand support. This study focused on the foot-position of caregivers as an adjustable and useful parameter. A wide stance decreases the stress on the lumbar vertebra. However, this foot-position increases loading of the spinae erector muscles. The aim of this study was to investigate the relationship of anterior-posterior and lateral-medial distances between feet and activity of the spinae erector muscles to determine the optimal foot-position for reducing stress on the lumbar vertebra without increasing spinae erector muscle load. [Participants and Methods] Five young male participants were asked to provide sit-to-stand support 10 times using nine normalized foot-positions with different anterior-posterior and lateral-medial distances. Surface electromyograms of the erector spinae and lower limb muscles were measured during sit-to-stand support. [Results] The results showed that the optimal foot-position (anterior-posterior 55%, lateral-medial 20% of body height) increased muscle activity within the lower limb muscles compared with the lower back muscles and did not increase loads on the erector spinae muscle. [Conclusion] Optimizing foot-position can reduce stress on the lumbar vertebra without increasing load on the spinae erector muscles.

Posture Recognition Method for Caregivers during Postural Change of a Patient on a Bed using Wearable Sensors

“…Such a type of patient handling causes lower back pain among caregivers as a patient is frequently repositioned on a bed [15]. As explained above, arm movements and foot positions are important factors for patient handling [11][12][13]. Thus, this study proposes the recognition method for various foot positions and arm movements of caregivers using a postural recognition method during postural change for a patient on a bed.…”

“…However, this system cannot suggest caregiver ways to adjust to an appropriate posture because the system measures only the trunk angle. Several factors, such as the foot position and arm movement, are useful to achieve suitable postures to prevent lower back pain during patient handling [11][12][13]. Therefore, a simple and wearable system that monitors the trunk angle, foot position, and arm movement is being develop [14].…”

Foot Position Measurement during Assistive Motion for Sit-to-Stand Using a Single Inertial Sensor and Shoe-Type Force Sensors

“…Posture adjustment based on ergonomics has been found to be effective for reducing lumbar load during manual lifting [ 4 ]. Trunk angle and foot position have been considered important posture parameters for reducing the lumbar load during manual lifting [ 5 , 6 , 7 , 8 ]. Hoogendoorn et al reported that trunk flexion and rotation are risk factors for the development of LBP [ 5 ], whereas Delisle et al found that strategic foot placement might improve lumbar load during manual handling [ 6 , 7 ].…”

“…Hoogendoorn et al reported that trunk flexion and rotation are risk factors for the development of LBP [ 5 ], whereas Delisle et al found that strategic foot placement might improve lumbar load during manual handling [ 6 , 7 ]. Our previous studies suggest that the adjustment of the quantitative foot position could reduce the lumbar load during assistive motion for sit-to-stand [ 8 , 9 ]. A previous investigation using computational musculoskeletal simulation revealed that foot position with long anteroposterior foot distance can reduce the compression stress in the L4–L5 joint [ 9 ].…”

“…Furthermore, a previous study that used electromyography revealed that the optimal foot position (foot distances in the anteroposterior and lateromedial directions at 55% and 20% of the body height, respectively) provided the use of the lower limb instead of the lumbar spine during assistive motion for sit-to-stand. [ 8 ]. Foot position is considered an effective posture parameter because it can be easily adjusted in the initial posture [ 8 , 9 ].…”