Jaap Van Dieen

Vrije Universiteit Amsterdam | VU · Human Movement Sciences

Evoking muscle responses by electrical vestibular stimulation (EVS) may help to understand the contribution of the vestibular system to postural control. Although paraspinal muscles play a role in postural stability, the vestibulo‐muscular coupling of these muscles during walking has rarely been studied. This study aimed to investigate how vestibul...

Objective The aim of this study was to evaluate the effect of perturbation-based treadmill training on gait quality in daily life, a predictor of fall risk that was used as the primary outcome. An additional aim was to evaluate the effects on secondary outcomes, including balance, gait performance, self-efficacy, daily-life physical activity, and f...

PurposeThe goal of this study was to assess differences in low back stabilization and underlying mechanisms between patients with low back pain (LBP) and healthy controls. It has been hypothesized that inadequate trunk stabilization could contribute to LBP through high tissue strains and/or impingement. Evidence to support this is inconsistent, and...

While active back-support exoskeletons can reduce mechanical loading of the spine, current designs include only one pair of actuated hip joints combined with a rigid structure between the pelvis and trunk attachments, restricting lumbar flexion and consequently intended lifting behavior. This study presents a novel active exoskeleton including actu...

Feedback stabilization of upright standing postures should be reflected by a time-lagged relationship between the ground reaction force (GRF) and the center of mass (COM) state. In this study, we propose a model relating corrective ground reaction forces ( F corr ) to preceding COM position (PCOM) and velocity (VCOM). We first checked the model’s v...

Background As we age, avoiding falls becomes increasingly challenging. While balance training can mitigate such challenges, the specific mechanisms through which balance control improves remains unclear. Methods We investigated the impact of balance training in older adults on feedback control after perturbations, focusing on kinematic balance rec...

Objective To evaluate the effect of the Nordic hamstring exercise on normalized muscle activity and relative contribution of the biceps femoris long head, semitendinosus, and semimembranosus through multichannel electromyography in the late-swing phase of high-speed running. Design A pragmatic, 2-arm, single-center randomized controlled trial. Par...

Background Unstable gait leading to falls negatively impacts the quality of life in many people with Parkinson’s disease (PD). Systematic review evidence provides moderate to strong evidence of efficacy for a wide range of physiotherapy-based interventions to reduce gait impairment. However, outcomes have often focused on gait assessments conducted...

Background Vestibulospinal reflexes play a role in maintaining the upright posture of the trunk. Head orientation has been shown to modify the vestibulospinal reflexes during standing. This study investigated how vestibular signals affect paraspinal muscle activity during walking, and whether head orientation changes these effects. Methods Sixteen...

Background Variational AutoEncoders (VAE) might be utilized to extract relevant information from an IMU-based gait measurement by reducing the sensor data to a low-dimensional representation. The present study explored whether VAEs can reduce IMU-based gait data of people after stroke into a few latent features with minimal reconstruction error. Ad...

Occupational lifting guidelines aiming to prevent work-related low-back pain (LBP) and clinical LBP guidelines on the management of LBP can provide seemingly conflicting messages concerning engagement in lifting. This conflict can potentially hinder progress in the prevention and management of LBP. In this paper, we identify and elaborate on tensio...

Vestibulospinal reflexes play a role in maintaining the upright posture of the trunk. Head orientation has been shown to modify the vestibulospinal reflexes during standing. This study investigated how vestibular signals affect paraspinal muscle activity during walking, and whether head orientation changes these effects. Sixteen participants were i...

Transtibial prosthetic users do often struggle to achieve an optimal prosthetic fit, leading to residual limb pain and stump-socket instability. Prosthetists face challenges in objectively assessing the impact of prosthetic adjustments on residual limb loading. Understanding the mechanical behaviour of the pseudo-joint formed by the residual bone a...

Background Gait speed is often used to estimate the walking ability in daily life in people after stroke. While measuring gait with inertial measurement units (IMUs) during clinical assessment yields additional information, it remains unclear if this information can improve the estimation of the walking ability in daily life beyond gait speed. Obj...

Purpose Sitting balance on an unstable surface requires coordinated out-of-phase lumbar spine and provides sufficient challenge to expose quality of spine control. We investigated whether the quality of spine coordination to maintain balance in acute low back pain (LBP) predicts recovery at 6 months. Methods Participants in an acute LBP episode (n...

Introduction Sitting on an unstable surface is a common paradigm to investigate trunk postural control among individuals with low back pain (LBP), by minimizing the influence lower extremities on balance control. Outcomes of many small studies are inconsistent (e.g., some find differences between groups while others do not), potentially due to conf...

Background Randomized controlled trials (RCTs) indicate that power training has the ability to improve muscle power and physical performance in older adults. However, power training definitions are broad and previously-established criteria are vague, making the validity and replicability of power training interventions used in RCTs uncertain. Obje...

Background Despite the increasing number of research studies examining the effects of age on the control of posture, the number of annual fall-related injuries and deaths continues to increase. A better understanding of how old age affects the neural mechanisms of postural control and how countermeasures such as balance training could improve the n...

Background: Previous research shows that power training can increase power output in older adults and may also improve physical performance, physical functioning, and independence. However, power training interventions have not been optimized for older adults. The aim of this study was to assess the feasibility and preliminary effectiveness of a po...

Falls are a problem, especially for older adults. Placing our feet accurately relative to the center-of-mass helps us to prevent falling during gait. The degree of foot placement control with respect to the center-of mass kinematic state is decreased in older as compared to young adults. Here, we attempted to train mediolateral foot placement contr...

Evoking muscle responses by electrical vestibular stimulation (EVS) may help to understand the contribution of the vestibular system to postural control. Although paraspinal muscles play a role in postural stability, the vestibulo-muscular coupling of these muscles during walking has rarely been studied. This study aimed to investigate how vestibul...

Dutch poster with first findings of SensIMoveS project

Low-back pain often coincides with altered neuromuscular control, possibly due to changes in spine stability resulting from injury or degeneration, or due to effects of nociception. The relative importance of these mechanisms, and their possible interaction, are unknown. In spine bending, the bulk of the load is borne by the IVD, yet the acute effe...

Walking without falling requires stabilization of the trajectory of the body center of mass relative to the base of support. Model studies suggest that this requires active, feedback control, especially in the mediolateral direction. In older adults and in individuals with neurological or orthopedic disorders that affect walking ability, falls duri...

Parkinson's disease (PD) affects 10 million people globally. PD causes unstable gait and falls in 70% of the patients and leads to many negative outcomes. Treadmill training is effective in improving gait and reducing falls, especially when combined with gait adaptations. However, the neural mechanisms behind these effects are unclear. Within Steps...

Background Differences in variability of trunk motor behavior between people with and without low back pain (LBP) have been reported in the literature. However, the direction and consistency of these differences remain unclear. Understanding variability of trunk motor behavior between individuals with LBP and those without is crucial to better unde...

This study investigated the effects of back muscle fatigue on the estimation of low-back loads and active low-back moments during lifting, using an EMG and kinematics based model calibrated with data from an unfatigued state. Fourteen participants performed lifting tasks in unfatigued and fatigued states. Fatigue was induced through semi-static for...

The aim of this study was to evaluate the effect of a Nordic hamstring exercise intervention on biceps femoris long head, semitendinosus, and semimembranosus muscle’s activity and relative contributions through multichannel electromyography. Twenty-four injury-free male basketball players (mean age 20 [3] y) were randomly assigned to a 12-week inte...

Background In treatment of low-back pain (LBP), motor control exercises have shown to be superior to minimal interventions, but not to any other form of exercise therapy. Knowledge about variability in trunk motor behavior may help to identify patients that may be more likely to benefit from motor control exercises. Objective This systematic review...

Understanding the mechanisms humans use to stabilize walking is vital for predicting falls in elderly. Modeling studies identified two potential mechanisms to stabilize gait in the anterior-posterior direction: foot placement control and ankle push-off control: foot placement depends on position and velocity of the center-of-mass (CoM) and push-off...

Objective: To provide reference values of cardiorespiratory fitness for individuals post-stroke in clinical rehabilitation and to gain insight in characteristics related to cardiorespiratory fitness post stroke. Design: A retrospective cohort study. Reference equations of cardiopulmonary fitness corrected for age and sex for the 5th,25th, 50th,...

Stretching is applied to lengthen shortened muscles in pathological conditions such as joint contractures. We investigated (i) the acute effects of different types of stretching, i.e. constant length (CL) and constant force (CF) stretching, on acute deformations and changes in passive mechanical properties of medial gastrocnemius muscle (MG) and (i...

During standing the center of mass (CoM) can be controlled relative to the base of support by applying ankle moments to shift the center of pressure (CoP mechanism). An additional mechanism is the counter-rotation mechanism, i.e., changing the angular momentum of segments around the CoM to change the direction of the ground reaction force. In this...

Introduction: Lifestyle factors are expected to contribute to the persistence and burden of low-back pain (LBP). However, there are no systematic reviews on the (cost-)effectiveness of combined lifestyle interventions for overweight or obese people with LBP. Aim: To assess whether combined lifestyle interventions are (cost-)effective for people...

Introduction Negative pain-related cognitions are associated with persistence of low-back pain (LBP), but the mechanism underlying this association is not well understood. We propose that negative pain-related cognitions determine how threatening a motor task will be perceived, which in turn will affect how lumbar movements are performed, possibly...

Falls are a problem, especially for older adults. Placing our feet accurately relative to the center-of-mass helps us to prevent falling during gait. The degree of foot placement control with respect to the center-of mass kinematic state is decreased in older as compared to young adults. Here, we attempted to train foot placement control in healthy...

Purpose: This study assessed activity distribution among the hamstring muscles during high-speed running. The objective was to compare within and between muscle activity, relative contribution and hip and knee joint angles at peak muscle activity during high-speed running. Methods: Through multichannel electromyography, we measured muscle activi...

This study assessed activity distribution among the hamstring muscles during the Nordic hamstring exercise (NHE). The objective was to compare muscle activity between and within muscles during the NHE to add insights in its underlying protective mechanism. Through multichannel electromyography, we measured muscle activity in male basketball players...

Standing balance is often more unstable when visually pursuing a moving target than when fixating on a stationary one. These effects are common in both young and older adults when the head is restrained during visual task performance. The present study focused on the role of head motion on standing balance during smooth pursuit as a function of age...

In human walking, power for propulsion is generated primarily via ankle and hip muscles. The addition of a ‘passive’ hip spring to simple bipedal models appears more efficient than using only push-off impulse, at least, when hip spring associated energetic costs are not considered. Hip flexion and retraction torques, however, are not ‘free’, as the...

Objective Individuals after stroke are less active, experience more fatigue, and perform activities at a slower pace than peers with no impairments. These problems might be caused by an increased aerobic energy expenditure during daily tasks and a decreased aerobic capacity after stroke. The aim of this study was to quantify relative aerobic load (...

Objective: To investigate whether 6-min walking is fatiguing for polio survivors, and how fatigue influences their normal and adaptive walking. Design: Cross-sectional study. Patients: Polio survivors (n = 23) with ≥ 1 fall and/or fear of falling reported in the previous year and healthy individuals (n = 11). Methods: Participants performed...

In this paper we review what mechanisms are used to stabilize human bipedal gait. Based on mechanical reasoning, potential mechanisms to control the body center of mass trajectory are modulation of foot placement, stance leg control consisting of modulation of ankle moments and push-off forces, and modulations of the body’s angular momentum. The fi...

Background Research suggests that muscle power is a more critical determinant of physical functioning in older adults than muscle strength. The objective of this study was to systematically review the literature on the effect of power training compared to strength training in older adults on tests for muscle power, two groups of activity-based test...

Mechanical loading of the low-back is an important risk factor for the development of low-back pain. Real-time estimation of the L5S1 joint moment (ML5S1) can give an insight to reduce mechanical loading. Model accuracy depends on sensor information, limiting the number of input variables to estimate ML5S1 increases practical feasibility, but may d...

Vestibular information modulates muscle activity during gait, presumably to contribute to stability. If this is the case, stronger effects of perturbing vestibular information on local dynamic stability of gait, a measure of the locomotor system’s response to small, naturally occurring perturbations, can be expected for narrow-base walking (which n...

The analysis of single motor unit (SMU) activity provides the foundation from which information about the neural strategies underlying the control of muscle force can be identified, due to the one-to-one association between the action potentials generated by an alpha motor neuron and those received by the innervated muscle fibers. Such a powerful a...

Introduction: Chronic low back pain is a common condition that imposes an enormous burden on individuals and society. Physical exercise with education is the most effective treatment, but generally results in small, albeit significant improvements. However, which type of exercise is most effective remains unknown. Core stability training is often u...