The validity of assessing temporal events, sub-phases and trunk kinematics of the sit-to-walk movement in older adults using a single inertial sensor

Abstract

a b s t r a c tThe aim of this study was to develop a method to identify temporal events, sub-phases and trunk kinematics of the sit-to-walk (STW) using a single inertial sensor (IS) worn at the lower back and to determine the validity of this method. Twenty-seven healthy older adults performed a STW movement, which started from sitting in a chair and included walking 3 m.Participants' movements were recorded with the IS, a reference measurement system consisting of an optical motion capture system (3 markers on the IS and one on each foot) and on-off switches located in the seat of the chair.Using the data from the IS and the reference measurement systems, the following signals and variables were calculated and compared: 3D IS motion (accelerations, velocities, displacements and angles), temporal events (start of trunk movement, seat-off, end of trunk flexion phase, end of trunk rising phase and gait initiation) and trunk kinematics (flexion range, maximum flexion velocity, maximum forward velocity and forward velocity during seat-off and at first heel-strike and maximum vertical velocity and vertical velocity at first heel-strike).For most variables acceptable differences (RMSE o 10%) were found between IS and reference measurement systems, except for sideways displacements and non-sagittal plane rotations. Furthermore, good results were found for temporal event detection, with ICC values for all variables being 0.988 or higher. With exception of the vertical velocity at heel-strike agreement for trunk kinematics was high, with ICC values being 0.867 or higher.

Is the Assessment of 5 Meters of Gait with a Single Body-Fixed-Sensor Enough to Recognize Idiopathic Parkinson’s Disease-Associated Gait?

“…1, 2) in the anterior-posterior direction (AP) were calculated from the raw acceleration and angular velocity signals recorded on the low-back, including the pre and post standing phases 27. Further details of these calculations are found in the Appendix 1 of supplementary material.

Figure 1Typical example of forward velocity signal (in AP direction), forward displacement signal, acceleration signals in the three axes and angular velocity signals in the three planes from a healthy control subject.

Figure 2Typical example of forward velocity signal (in AP direction), forward displacement signal, acceleration signals in the three axes and angular velocity signals in the three planes from a subject with Parkinson’s disease.

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Validity and Reliability of a New Inertial Device for Monitoring Range of Motion at the Pelvis during Sexual Intercourse

“…Other studies that have validated inertial sensors by comparing them with optical systems for capturing the range of motion in the same axis of movement (flexion-extension) found the following systematic differences in evaluations of the hip movement: [21]. The following additional statistics were reported: R 2 = 0.78 [21] and R 2 = 0.82 [34]; SEM = 2.47 • [32] and SEM = 3 • [31,33], and an ICC of 0.99 [35].…”

“…Other studies that have validated inertial sensors by comparing them with optical systems for capturing the range of motion in the same axis of movement (flexion-extension) found the following systematic differences in evaluations of the hip movement: 1.55° (during a hip flexion test) [30] [32]; in evaluations of the range of motion of the trunk during a sit-to-walk test: 0.45° [30]; in the range of motion of the lumbar spine during a standing forward flexion test: 1.82° [33], in the range of lumbar-pelvic movement during a standing forward flexion test: 3.06° [21]. The following additional statistics were reported: R 2 = 0.78 [21] and R 2 = 0.82 [34]; SEM = 2.47° [32] and SEM = 3° [31,33], and an ICC of 0.99 [35].…”

“…The test-retest reliability was analyzed with a five-second break. As this is the first study to analyze the validity and reliability of an inertial device for monitoring range of motion at the pelvis during sexual activity in men and women, the results could only be compared with previous research on the validity or reliability of similar devices testing different variables and a similar range of motion (same axis of movement) [21,29,[31][32][33][34][35][36]. Further research on the validity and reliability of other devices for monitoring range of motion at the pelvis during sexual activity is needed to make it easier to compare systems.…”

A Review of Activity Trackers for Senior Citizens: Research Perspectives, Commercial Landscape and the Role of the Insurance Industry

“…Zhang et al [116] proved that a pendant-worn sensor could be reliably used for assessing chair rise monitoring. Finally, other published works investigated the possibility to automate the assessment with sensors attached to the lower-back during sit-to-stand [117], sit-to-walk [118], and 30 s chair test [119]. …”