Validation of an algorithm to assess regular and irregular gait using inertial sensors in healthy and stroke individuals

Real-world gait and turning in individuals scheduled for total knee arthroplasty

BACKGROUND

Improving mobility - specifically walking - is an important treatment goal of total knee arthroplasty. Objective indicators for mobility, however, are lacking in clinical evaluations. This study aimed to compare real-world gait and turning between individuals scheduled for total knee arthroplasty and healthy controls, using continuous monitoring with inertial measurement units.

METHODS

Real-world gait and turning data were collected for 5-7 days in individuals scheduled for total knee arthroplasty (n = 34) and healthy controls (n = 32) using inertial measurement units on the feet and lower back. Gait and turning parameters were compared between groups using a linear regression model. Data was further analyzed by stratification of gait bouts based on bout length, and turns based on turning angle and turning direction.

FINDINGS

Dominant real-world gait speed was 0.21 m/s lower in individuals scheduled for total knee arthroplasty compared to healthy controls. Stride time was 0.05 s higher in individuals scheduled for total knee arthroplasty. Step time asymmetry was not different between the groups. Regarding walking activity, individuals scheduled for total knee arthroplasty walked 72 strides/h less than healthy controls, and maximum bout length was 316 strides shorter. Irrespective of the size of the turn, turning velocity was lower in individuals scheduled for total knee arthroplasty.

INTERPRETATION

Individuals scheduled for total knee arthroplasty showed specific walking and turning limitations in the real-world. Parameters derived from inertial measurement units reflected a rich profile of real-world mobility measures indicative of walking limitation of individuals scheduled for total knee arthroplasty, which may provide a relevant outcome dimension for future studies.

Effect of a soft exosuit on daily life gait performance in people with incomplete spinal cord injury: study protocol for a randomized controlled trial

BACKGROUND

People with incomplete spinal cord injury (iSCI) often have gait impairments that negatively affect daily life gait performance (i.e., ambulation in the home and community setting) and quality of life. They may benefit from light-weight lower extremity exosuits that assist in walking, such as the Myosuit (MyoSwiss AG, Zurich, Switzerland). A previous pilot study showed that participants with various gait disorders increased their gait speed with the Myosuit in a standardized environment. However, the effect of a soft exosuit on daily life gait performance in people with iSCI has not yet been evaluated.

OBJECTIVE

The primary study objective is to test the effect of a soft exosuit (Myosuit) on daily life gait performance in people with iSCI. Second, the effect of Myosuit use on gait capacity and the usability of the Myosuit in the home and community setting will be investigated. Finally, short-term impact on both costs and effects will be evaluated.

METHODS

This is a two-armed, open label, randomized controlled trial (RCT). Participants will be randomized (1:1) to the intervention group (receiving the Myosuit program) or control group (initially receiving the conventional program). Thirty-four people with chronic iSCI will be included. The Myosuit program consists of five gait training sessions with the Myosuit at the Sint Maartenskliniek. Thereafter, participants will have access to the Myosuit for home use during 6 weeks. The conventional program consists of four gait training sessions, followed by a 6-week home period. After completing the conventional program, participants in the control group will subsequently receive the Myosuit program. The primary outcome is walking time per day as assessed with an activity monitor at baseline and during the first, third, and sixth week of the home periods. Secondary outcomes are gait capacity (10MWT, 6MWT, and SCI-FAP), usability (D-SUS and D-QUEST questionnaires), and costs and effects (EQ-5D-5L).

DISCUSSION

This is the first RCT to investigate the effect of the Myosuit on daily life gait performance in people with iSCI.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05605912. Registered on November 2, 2022.

Assessment of Foot Strike Angle and Forward Propulsion with Wearable Sensors in People with Stroke

Effective retraining of foot elevation and forward propulsion is a critical aspect of gait rehabilitation therapy after stroke, but valuable feedback to enhance these functions is often absent during home-based training. To enable feedback at home, this study assesses the validity of an inertial measurement unit (IMU) to measure the foot strike angle (FSA), and explores eight different kinematic parameters as potential indicators for forward propulsion. Twelve people with stroke performed walking trials while equipped with five IMUs and markers for optical motion analysis (the gold standard). The validity of the IMU-based FSA was assessed via Bland-Altman analysis, ICC, and the repeatability coefficient. Eight different kinematic parameters were compared to the forward propulsion via Pearson correlation. Analyses were performed on a stride-by-stride level and within-subject level. On a stride-by-stride level, the mean difference between the IMU-based FSA and OMCS-based FSA was 1.4 (95% confidence: -3.0; 5.9) degrees, with ICC = 0.97, and a repeatability coefficient of 5.3 degrees. The mean difference for the within-subject analysis was 1.5 (95% confidence: -1.0; 3.9) degrees, with a mean repeatability coefficient of 3.1 (SD: 2.0) degrees. Pearson's r value for all the studied parameters with forward propulsion were below 0.75 for the within-subject analysis, while on a stride-by-stride level the foot angle upon terminal contact and maximum foot angular velocity could be indicative for the peak forward propulsion. In conclusion, the FSA can accurately be assessed with an IMU on the foot in people with stroke during regular walking. However, no suitable kinematic indicator for forward propulsion was identified based on foot and shank movement that could be used for feedback in people with stroke.