Noël L W Keijsers

Sint Maartenskliniek · Department for Scientific Research

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...

Objective To compare real-world gait and turning between individuals scheduled for total knee arthroplasty (TKA) and healthy controls, using continuous monitoring with inertial measurement units (IMUs). Design Real-world gait and turning data were collected for 5-7 days in individuals scheduled for TKA (n=34) and healthy controls in the same age r...

Assessing a patient's musculoskeletal function during over-ground walking is a primary objective in post-stroke rehabilitation, due to the importance of walking recovery for everyday life. However, the quantitative assessment of musculoskeletal function currently requires lab-constrained equipment, and labor-intensive analyses, which hampers assess...

Background: Individuals with Hereditary Motor and Sensory Neuropathy (HMSN) are commonly provided with orthopedic footwear to improve gait. Although orthopedic footwear has shown to improve walking speed and spatiotemporal parameters, its effect on gait adaptability has not been established. Research question: What is the effect of orthopedic fo...

Introduction: The population of people with a spinal cord injury (SCI) is changing to a diverse population with an increasing number of incomplete lesions. Often, these individuals have the capacity to walk, but experience disabling gait impairments. Case presentation: The course of a 34-year-old male with a chronic incomplete traumatic cervical...

ClinicalTrials.gov Identifier: NCT05827380 ClinicalTrials.gov Identifier: NCT05825053

Abstract Background Hereditary motor and sensory neuropathies (HMSN), also known as Charcot-Marie-Tooth disease, are characterized by affected peripheral nerves. This often results in foot deformities that can be classified into four categories: (1) plantar flexed first metatarsal, neutral hindfoot, (2) plantar flexed first metatarsal, correctable...

Background Most people with Parkinson’s disease (PD) walk with a smaller mediolateral base of support (BoS) compared to healthy people, but the underlying mechanisms remain unknown. Reduced trunk motion in people with PD might be related to this narrow-based gait. Here, we study the relationship between trunk motion and narrow-based gait in health...

Different methods exist to select strides that represent preferred, steady-state gait. The aim of this study was to identify the effect of different stride-selection methods on spatiotemporal gait parameters to analyze steady-state gait. A total of 191 patients with hip or knee osteoarthritis (aged 38–85) wearing inertial sensors walked back and fo...

Background Spasticity, i.e. stretch hyperreflexia, increases joint resistance similar to symptoms like hypertonia and contractures. Botulinum neurotoxin-A (BoNT-A) injections are a widely used intervention to reduce spasticity. BoNT-A effects on spasticity are poorly understood, because clinical measures, e.g. modified Ashworth scale (MAS), cannot...

p>This study presents a technology that can provide computer-based, signal-driven, musculoskeletal model-based analysis for musculoskeletal assessment post-stroke during gait. It comprises a modular 64 textile-embedded electromyography (EMG) leg garment integrated with a generalized and automated algorithm for the fast localization of leg muscles a...

p>This study presents a technology that can provide computer-based, signal-driven, musculoskeletal model-based analysis for musculoskeletal assessment post-stroke during gait. It comprises a modular 64 textile-embedded electromyography (EMG) leg garment integrated with a generalized and automated algorithm for the fast localization of leg muscles a...

Dynamic balance control during human walking can be described by the distance between the mediolateral (ML) extrapolated center of mass (XCoM) position and the base of support, the margin of stability (MoS). The ML center of mass (CoM) position during treadmill walking can be estimated based on kinematic data (marker-based method) and a combination...

Purpose: The System Usability Scale (SUS) is the most commonly used questionnaire to assess usability of healthcare innovations but is not available in Dutch (D-SUS). This study aims to translate the SUS to Dutch and to determine its internal consistency, test-retest reliability, and construct validity in healthcare innovations focused on rehabili...

Background: Impaired balance during walking is a common problem in people with incomplete spinal cord injury (iSCI). To improve walking capacity, it is crucial to characterize balance control and how it is affected in this population. The foot placement strategy, a dominant mechanism to maintain balance in the mediolateral (ML) direction during wal...

Background Most people with Parkinson’s Disease (PD) walk with a smaller mediolateral base of support (BoS) compared to healthy people, but the underlying mechanisms remain unknown. According to the extrapolated center of mass (XCoM) concept, a decrease in mediolateral XCoM excursion would require a smaller mediolateral BoS to maintain a constant m...

The aim of this study was to objectively assess and compare gait capacity and gait performance in rehabilitation inpatients with stroke or incomplete spinal cord injury (iSCI) using inertial measurement units (IMUs). We investigated how gait capacity (what someone can do) is related to gait performance (what someone does). Twenty-two inpatients (11...

Background Inertial sensors hold the promise to objectively measure functional recovery after total knee (TKA) and hip arthroplasty (THA), but their value in addition to patient-reported outcome measures (PROMs) has yet to be demonstrated. This study investigated recovery of gait after TKA and THA using inertial sensors, and compared results to rec...

Introduction Healthcare expenses are reaching unaffordable levels worldwide and reverse innovation could play a role in decreasing these expenses and improving healthcare accessibility. The ReMotion Knee, a prosthetic knee primarily developed for low-income countries, could serve as a reverse innovation for people with a lower limb amputation. This...

Background and Objectives Compensation strategies are essential in Parkinson’s disease (PD) gait rehabilitation. However, besides external cueing, these strategies have rarely been investigated systematically. We aimed to: (1) establish the patients’ perspective on the efficacy and usability of five different compensation strategies; (2) quantify t...

Despite the absence of somatosensory information from the lower extremities, people with complete spinal cord injury (SCI) can maintain postural stability in an exoskeleton. This is partly because humans are able to reweigh the relative dependence on each of the senses. However, when the sensory environment is changed, people with complete SCI are...

Background and aim People with Parkinson’s Disease (PD) typically walk with a narrow base of support [1]. The underlying mechanism is yet unknown. We hypothesize that trunk rigidity in people with PD reduces the mediolateral extrapolated center of mass (XCoM) excursions during gait, and these subsequently reduce the required base of support to main...

BACKGROUND: End-stage osteoarthritis (OA) of the knee is characterized by pain and joint stiffness. When these symptoms substantially limit daily-life activities, total knee replacement (TKR) is considered. The decision towards TKR strongly hinges on subjective patient report of the extent of daily-life limitation, which may poorly reflect actual p...

Background and aim: Impaired balance during walking is a common problem in people with incomplete spinal cord injury (iSCI). To improve walking capacity, it is crucial to characterize balance control and how it is affected in this population. The foot placement strategy, a dominant mechanism to maintain balance in the mediolateral (ML) direction du...

Immersive virtual reality (VR) represents a viable technology to support rehabilitation and promote the recovery of upper limb functions after stroke. Nonetheless, it has not been determined yet if VR can elicit movements that share the same kinematic characteristics of those occurring in the real world (RW), thus positively impacting arm use in da...

Background Benefits of peroneal functional electrical stimulation in people with post-stroke drop foot may particularly emerge in environments that require continual gait adaptation. Such adaption is known to increase the attentional demands of gait. Research questions Is performance of a target stepping task more accurate and less attention deman...

Objective: To examine changes in quality of life (QoL) after an eight-week period of robotic exoskeleton training in a homogeneous group of patients with chronic complete spinal cord injury (SCI). Design: Prospective single-group pre-post study. Setting: Rehabilitation center. Participants: Patients with a chronic (>6 months) motor complete...

Purpose: Exoskeleton use by people with complete spinal cord injury (SCI) in daily life is challenging. To optimize daily exoskeleton use, a better understanding of the purpose of use and the accompanying improvements are needed. The perspective of experienced exoskeleton users could guide design improvements. Methods: Face-to-face semi-structur...

Background: Shoe heel height is considered to influence prosthetic alignment, walking comfort, and gait symmetry in people with a transtibial amputation (TTA). However, research on the effect of heel height is scarce, and no evidence is available on the effects of variations smaller than 20 mm. These small heel height variations between store-boug...

Background Orthopedic footwear is often prescribed to improve postural stability during standing and walking in individuals with Hereditary Motor Sensory Neuropathy. However, supporting evidence in literature is scarce. The aim of this study was to investigate the effect of orthopedic footwear on quiet standing balance, gait speed, spatiotemporal p...

Virtual reality (VR) has recently emerged as a promising technology to rehabilitate upper limb functions after stroke. To promote the recovery of functions, retraining physiological movement patterns is essential. However, it is still unclear whether VR can elicit functional movements that are similar to those performed in the real world (RW). This...

Balance and walking capacity are often impaired in patients with incomplete spinal cord injury (iSCI), frequently resulting in reduced functional ambulation and participation. Therefore, improvement of balance and walking capacity are important rehabilitation goals. Walking adaptability training seems to be a promising intervention to improve walki...

Introduction: Restoration of physical functioning is a major aim of total joint arthroplasty, which is typically evaluated by subjective patient-reported outcome measures (PROMs). In this study, we aimed to investigate objective recovery of gait - including turning, upper body motion, and gait automaticity - after total knee (TKA) and hip arthropla...

Objective: Toe walking due to progressive shortening of the calf muscles is common in people with hereditary spastic paraplegia. Achilles tendon lengthening is a treatment option, but clinicians are often hesitant to use this procedure, as it may result in weakening of the calf muscles and, subsequently, in reduced ankle power and knee instability...

Gait impairments in people with Charcot-Marie-Tooth disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed an...

Background: Recent research has shown that leg dominance has an impact on gait and that this impact is significant enough that a leg dominance scores are worth developing. However, it remains unclear how leg dominance impacts plantar pressure measurements. Some studies assume that measurements from opposing feet are identical while others assume th...

This study aims were twofold: (1) to evaluate the construct validity of the Repetitive Movement Test (RMT) a novel test developed for Wheelchair Rugby classification which evaluates arm coordination impairment at five joints – shoulder, elbow, forearm, wrist and fingers – and (2), pending sufficiently positive results, propose objective minimum imp...

Background Since adequate sleep is essential for optimal inpatient rehabilitation, there is an increased interest in sleep assessment. Unobtrusive, contactless, portable bed sensors show great potential for objective sleep analysis. Objective The aim of this study was to investigate the feasibility of a bed sensor for continuous sleep monitoring o...

Previous research showed that an Inertial Measurement Unit (IMU) on the anterior side of the shank can accurately measure the Shank-to-Vertical Angle (SVA), which is a clinically-used parameter to guide tuning of ankle-foot orthoses (AFOs). However, in this context it is specifically important that differences in the SVA are detected during the tun...

Diagnosing foot complaints using plantar pressure videos is complicated by the presence of confounding factors (e.g. age, weight). Outlier detection could help with diagnosis, but these confounding factors result in data that is not independent and identically distributed (IID) with respect to a specific patient. To address this non-IID problem, we...

Background: Exoskeleton use by people with complete spinal cord injury (SCI) in daily life is still a challenge. To optimize its daily life use, a better understanding of the purpose of use and the accompanying improvements are needed. The perspective of experienced exoskeleton users provides an important contribution to the improvement of future e...

The distance one can walk at a time could be considered an important functional outcome in people with a lower limb amputation. In clinical practice, walking distance in daily life is based on self-report (SIGAM mobility grade (Special Interest Group in Amputee Medicine)), which is known to overestimate physical activity. The aim of this study was...

Introduction: Overuse injuries often start with a musculoskeletal complaint, which can progress over time to an injury. Little or no information is known about the development and severity of overuse injuries in military recruits. This study describes the musculoskeletal complaints in Dutch military recruits during their basic training and examine...

A consequence of a complete spinal cord injury (SCI) is the loss of gait capacity. Wearable exoskeletons for the lower extremity enable household and community ambulation in people with SCI. This study assessed the amount, purpose, and location of exoskeleton use in the home and community environment, without any restrictions. The number of steps t...

BACKGROUND Since adequate sleep is essential for optimal inpatient rehabilitation, there is an increased interest in sleep assessment. Unobtrusive, contactless, portable bed sensors show great potential for objective sleep analysis. OBJECTIVE The aim of this study was to investigate the feasibility of a bed sensor for continuous sleep monitoring o...

An inertial measurement unit (IMU) seems to be a responsive measurement tool to assess the shank to vertical angle during walking (SVA). To be clinically applicable for tuning ankle foot orthosis (AFOs), the accuracy should be improved.

Background: The aetiology of chronic therapy resistant plantar fasciitis (CTRPF) is multifactorial with more focus in recent times on the gastroc-soleus complex. This study evaluates the effect of lengthening the gastrocnemius muscle in CTRPF. Methods: All patients with CRTPF complaints for at least one year underwent the same standard conservative...

The Shank-to-Vertical Angle (SVA) is a commonly used parameter to describe orthotic alignment. 3D gait analysis (3DGA) or 2D video analysis are usually used to assess the SVA, but are not always feasible in clinical practice. As an alternative, an Inertial Measurement Unit (IMU) attached and aligned to the shank might be used. This study aimed to i...

Recovery of the walking function is one of the most common rehabilitation goals of neurological patients. Sufficient and adequate sleep is a prerequisite for recovery or training. To objectively monitor patients’ progress, a combination of different sensors measuring continuously over time is needed. A sensor-based technological platform offers pos...

Background: In infants with indications of upper cervical dysfunction, the Flexion-Rotation-Test and Lateral-Flexion-Test are used to indicate reduced upper cervical range-of-motion (ROM). In infants, the inter-rater reliability of these tests is unknown. Objective: To assess the inter-rater reliability of subjectively and objectively measured ROM...

Quantitative analyses of plantar pressure images typically occur at the group level and under the assumption that individuals within each group display homogeneous pressure patterns. When this assumption does not hold, a personalized analysis technique is required. Yet, existing personalized plantar pressure analysis techniques work at the image le...

Powered robotic exoskeletons are a promising solution to enable standing and walking in patients with spinal cord injury (SCI). Although training and walking with an exoskeleton in motor complete SCI patients is considered safe, the risks of unexpected (technical) adverse events and the risk of fractures are not fully understood. This article repor...

Purpose of the article: Learning to use an exoskeleton is time consuming and diverse between users. Knowledge about trainability of exoskeleton skills is relevant for planning and expectation management. The objective was to assess predictors of exoskeleton skill performance during and after exoskeleton training. Materials and methods: Twenty-four...

Background: Improvement of balance control is an important rehabilitation goal for patients with motor and sensory impairments. To quantify balance control during walking, various stability outcome measures have described differences between healthy controls and patient groups with balance problems. To be useful for the evaluation of interventions...

Introduction: This study investigated the effect of operative claw toe correction with release of the metatarsophalangeal (MTP) joint, repositioning of the plantar fat pad and resection of the proximal interphalangeal joint on foot kinematics, plantar pressure distribution and Foot Function Index (FFI). Methods: Prospective experimental study wi...

Background: Gait impairments are common and disabling in chronic stroke patients. Pes equinovarus deformity is one of the primary motor deficits underlying reduced gait capacity after stroke. It predisposes to stance-phase instability and subsequent ankle sprain or falls. This instability is most pronounced when walking barefoot. Tarsal fusion is...

This study characterizes plantar pressure differences between hallux valgus patients and healthy controls using statistical parametric mapping (SPM). The plantar pressure differences are minimal which, combined with previous studies, suggest high variability in the plantar pressures of hallux valgus patients.

While dynamic plantar pressure measurements are commonly used for clinical evaluation of gait-related problems, computational analysis techniques for these datasets are few and far between. To address this issue, we introduce an open-access database of plantar pressure videos for researchers to develop algorithms around.

Background: Although posterior spinal correction and fusion surgery (PSF) of adolescent idiopathic scoliosis (AIS) limits counter rotation between thorax and pelvis, the physical function, and more specifically gait of these patients is only slightly affected after PSF. Possibly, shoulders-thorax counter-rotation increases to compensate for the lo...

Data reduction techniques are commonly applied to dynamic plantar pressure measurements, often prior to the measurement’s analysis. In performing these data reductions, information is discarded from the measurement before it can be evaluated, leading to unknown consequences. In this study, we aim to provide the first assessment of what impact data...

Background: Wearable exoskeletons can be a powerful tool for the facilitation of ambulation of complete Spinal Cord Injury (SCI) subjects, which has several psychological and physical advantages. However, exoskeleton control is difficult for this group of users and requires a long period of training. People with SCI not only lack the motor control...

Many patients with incomplete spinal cord injury (iSCI) have impaired gait and balance capacity, which may impact daily functioning. Reduced walking speed and impaired gait stability are considered important underlying factors for reduced daily functioning. With conventional therapy, patients are limited in training gait stability, but this can be...

Previous gait analysis studies of patients with an ankle arthrodesis have reported increased motion in the adjacent joints. However, of similar importance are the forces that act on the ipsi- and contralateral joints and the effect of ankle arthrodesis with regard to balance control. The purpose of the present study was to determine the joint momen...

Background: Pedobarography produces large sets of plantar pressure samples that are routinely subsampled (e.g. using regions of interest) or aggregated (e.g. center of pressure trajectories, peak pressure images) in order to simplify statistical analysis and provide intuitive clinical measures. Research question: We hypothesize that these data r...

Background context: Adolescent idiopathic scoliosis (AIS) patients perform surprisingly well after spinal correction and fusion. It was previously hypothesized that, during gait, certain mechanisms compensate for the loss in spinal motion. Still, previous studies could not identify such compensatory mechanisms in the lower body. Purpose: This st...

Importance Gait impairments are common in patients with chronic supratentorial upper motor neuron lesions and are a source of disability. Clinical management aimed at improving the gait pattern in these patients is generally perceived as a challenging task because many possible abnormalities may interact. Moreover, a multitude of treatment options...

Purpose: To investigate the effects of posterior spinal fusion (PSF) and curve type on upper body movements in Adolescent Idiopathic Scoliosis (AIS) patients during gait. Methods: Twenty-four girls (12-18 years) with AIS underwent PSF. 3D-Gait-analyses were performed preoperatively, at 3 months and 1 year postoperatively. Mean position (0° repre...

Trunk coordination is essential for many activities of daily living in wheelchair users. This study investigated whether Fitts' law is applicable to trunk movements in a sitting position. Fourteen healthy adults performed two series of 24 tasks of trunk flexion–extension movements in a sitting position. The results showed significant linear relatio...