Alessio Gallina

Purpose In this study, we investigated whether experimental knee pain alters lower limb kinematics and knee arthrokinematics during gait, and if this motor adaptation depends on the spatial characteristics of the painful stimulus. Methods Twenty-one participants walked on a treadmill for 60-s trials, either without stimulation or while experiencin...

In this systematic review, we synthesize the literature investigating the effect of experimentally induced pain in the cervical, shoulder, or orofacial regions on cervical neuromuscular and kinematic features. Databases were searched up to November 1st, 2023. A total of 29 studies using hypertonic saline injection (n = 27) or glutamate injection (n...

BACKGROUND Clinicians and athletic training specialists often assess performance of single leg, weightbearing tasks to monitor rehabilitation progress and guide exercise progression. Some of the key metrics assessed are excessive pelvic motion, balance, and duration of each repetition of the exercise. Motion can be objectively characterized using m...

Background Clinicians and athletic training specialists often assess the performance of single-leg, weight-bearing tasks to monitor rehabilitation progress and guide exercise progression. Some of the key metrics assessed are excessive pelvic motion, balance, and duration of each repetition of the exercise. Motion can be objectively characterized us...

Background: Office workers are specifically vulnerable to headache conditions. Neck pain is reported by almost 80% of patients with headaches. Associations between currently recommended tests to examine cervical musculoskeletal impairments, pressure pain sensitivity and self-reported variables in headache, are unknown. Purpose: The aim of this stud...

Background: Headache and neck pain are closely related. Office-workers are regarded especially vulnerable for both conditions. The objectives of the study are, to examine the effects of a 12-month intervention, consisting of neck exercise and health promotion, on headache outcome variables in office workers in two public departments in Switzerland....

Purpose: To investigate the effect of trunk positions and experimental lumbar pain location on lumbar extensor muscles recruitment strategies. Methods: 19 healthy participants (10 men: 9 women), aged 25.3 ± 4.7 years, performed isometric back extension contractions in three positions: neutral, 45° and 90° trunk flexion and under three conditions...

UNSTRUCTURED Sport science and rehabilitation are naturally evolving towards the implementation of data-driven technology for the analysis of human motion. Analysis of movement has traditionally been taught, researched, and implemented in practice either visually, or using equipment often unavailable outside specialized research centers. The motion...

The active control of the lumbar musculature provides a stable platform critical for postures and goal-directed movements. Voluntary and perturbation-evoked motor commands can recruit individual lumbar muscles in a task-specific manner according to their presumed biomechanics. Here, we investigated the vestibular control of the deep and superficial...

The biomechanical assessment of pelvic kinematics during a single leg squat (SLS) commonly relies on expensive equipment, which precludes its wider implementation in ecological settings. Smartphone sensors could represent an effective solution to objectively quantify pelvic kinematics remotely, but their measure properties need to be evaluated befo...

Introduction When performing an exercise or a functional test, pain that is evoked by movement or muscle contraction could be a stronger stimulus for changing how individuals move compared to tonic pain. We investigated whether the decrease in muscle force production is larger when experimentally‐induced knee pain is directly associated to the torq...

Background: Office workers are specifically vulnerable to headache conditions. Neck pain is reported by almost 80% of patients with headaches. Associations between currently recommended tests to examine cervical musculoskeletal impairments, pressure pain sensitivity and self-reported variables in headache, are unknown. The aim of this study is to...

PurposeTo investigate if the recruitment of different regions within the lumbar extensor muscles in response to unexpected perturbations depends on trunk posture.Methods In a semi-seated posture, healthy adult participants experienced unexpected posterior-anterior trunk perturbations in three different postures: neutral, trunk flexion and left trun...

ABSTRACT Background The Cervical Radiculopathy Impact Scale (CRIS) and Patient Specific Functional Scale 2.0 (PSFS 2.0) are patient-reported outcome measures (PROMs) used to assess activity limitations in patients with cervical radiculopathy (CR). This study a) compared the CRIS subscale 3 and the PSFS 2.0 in patients with CR with respect to comple...

Background: Movement control tests (MCTs) are clinical tests to evaluate impairment of movement and associated neuromuscular control and are commonly used to evaluate people with neck pain or headache conditions. The aim of this study was to establish inter-rater reliability as well as discriminatory and predictive validity for seven MCTs of the up...

Background: Trunk kinematics during sit-to-stand is often impaired in individuals with musculoskeletal disorders. Trunk kinematics is commonly assessed in laboratories using motion capture; however, this equipment is often not available outside research centers. Smartphones are widely available and may be a suitable alternative to assess trunk ori...

Experimental pain models are frequently used to understand the influence of pain on the control of human movement. In this systematic review, we assessed the effects of experimentally induced pain in the lumbar region of healthy individuals on trunk muscle activity and spine kinematics. Databases were searched from inception up to 31st January 2022...

Purpose Conservative management of lumbar radiculopathy (LR) is the first treatment option. To date, systematic reviews and clinical practice guidelines have not considered the most appropriate timing of management. This study aimed to establish consensus on effective conservative treatment modalities across different stages (i.e., acute, sub-acute...

Objectives To determine if measures of cervical kinematics are altered in people with acute whiplash associated disorders (WAD) and secondarily, to examine whether kinematic variables are associated with self-reported outcomes. Methods We recruited people with acute WAD within 15 days after a motor vehicle collision and asymptomatic control partic...

The aim of this study was to examine for the presence of differences in neuromuscular and psychological function in individuals with recurrent neck pain (RNP) or chronic neck pain (CNP) following a whiplash trauma compared to healthy controls. A secondary aim was to examine whether neuromuscular characteristics together with psychological features...

High-density surface electromyography (HDsEMG) can be used to measure the spatial distribution of electrical muscle activity over the skin. As this distribution is associated with the generation and propagation of muscle fiber action potentials, HDsEMG is processed to extract information on regional muscle activation, muscle fiber characteristics a...

Objective Conservative management of cervical radiculopathy (CR) is a first treatment option as the risk–benefit ratio for surgery is less favorable. Systematic reviews and clinical practice guidelines reporting on the effectiveness of nonsurgical management have not considered the timing of management. The aim of this study was to establish consen...

Objective: To synthesise the current evidence regarding the predictive ability of measures of physical function (PF) of the neck region and perceived PF on prognosis following a whiplash injury. Methods: Electronic databases were searched by two independent reviewers up to July 2020, including MEDLINE, EMBASE, CINAHL, PsycINFO, Scopus and Web of...

Background Numerous studies report changes in neuromuscular control in people with low back pain (LBP). However, the relationship between pain and altered neuromuscular control is challenging to unravel given the heterogeneity that exists in clinical populations. One approach commonly adopted to overcome this issue is the use of experimental pain m...

Abstract Background Altered regional activation of the lumbar extensors has been previously observed in individuals with low back pain (LBP) performing high-effort and fatiguing tasks. It is currently unknown whether similar alterations can be observed during low-effort functional tasks. Similarly, previous studies did not investigate whether side...

Bi-articular muscles have traditionally been considered to exhibit homogeneous neuromuscular activation. The regional activation of bi-articular muscles, as revealed from high-density surface electromyograms, seems however to discredit this notion. We thus hypothesize the regional activation of bi-articular muscles may contribute to different actio...

A plethora of evidence supports the existence of neuromuscular changes in people with chronic spinal pain (neck and low back pain), yet it is unclear whether neuromuscular adaptations persist for people with recurrent spinal pain when in a period of remission. This systematic review aimed to synthesise the evidence on neuromuscular adaptations in p...

Key points Motor adaptation is thought to be a strategy to avoid pain. Current experimental pain models do not allow for consistent modulation of pain perception depending on movement. We showed that low‐frequency sinusoidal stimuli delivered at painful intensity result in minimal habituation of pain perception (over 60 s) and minimal stimulation a...

Introduction Cervical radiculopathy (CR) is a clinical condition whereby motor, reflex and/or sensory changes such as radicular pain, paraesthaesia or numbness can exist. Conservative management is a preferred first treatment option as the risk–benefit ratio for surgery is less favourable. Systematic reviews and treatment guidelines gather evidence...

Introduction: Not all factors that predict persistent pain and disability following whiplash injury are known. In particular, few physical factors, such as changes in movement and muscle behaviour, have been investigated. The aim of this study is to identify predictive factors that are associated with the development of persistent pain and disabil...

The purpose of this study was to examine scalene (SA) and sternocleidomastoid (SM) activation during normoxic (norm-ITL; FIO2 = 21%) and hypoxic (hyp-ITL; FIO2 = 15%) incremental inspiratory threshold loading (ITL). Thirteen healthy participants (33 ± 4 years, 9 female) performed two ITL tests breathing randomly assigned gas mixtures through an ins...

High-density surface electromyography (HDEMG) is an electrophysiological technique that can be used to quantify the spatial distribution of activity within muscles. When pain-free individuals perform sustained or repetitive tasks, different regions within a muscle become progressively more active; this is thought to reflect a strategy to redistribu...

Maintenance of upright standing posture has often been explained using the inverted pendulum model. This model considers the ankle plantarflexors to act as a single synergistic group. There are differences in muscle properties among the medial and lateral gastrocnemius (MG and LG, respectively) and the soleus that may affect their activation. Twelv...

Introduction Due to their complex anatomy, the general activation of lumbar muscles can be estimated with surface electromyography (sEMG) while intramuscular EMG is recommended to isolate information from different back muscles. Whether high-density sEMG recordings can represent the contribution of individual lumbar muscles, as identified with indw...

Introduction The course of spinal pain (neck or low back pain) is often described as episodic and intermittent, with more than one-third of people continuing to experience episodic symptoms 1 year after first onset. Although ongoing neuromuscular adaptations could contribute to recurrent episodes of pain, no systematic review has synthesised eviden...

Introduction Mitigating the transition from acute to chronic whiplash-associated disorders (WAD) is fundamental, and this could be achieved through early identification of individuals at risk. Several physical factors such as angular velocity, smoothness of neck movement and coactivation of neck flexors and extensors, have been observed in patients...

Introduction Chronic, non-specific low back pain is a major global cause of disability. One factor which might potentially contribute to ongoing pain is maladaptive variation in the level of activity in the lumbar musculature. Several studies have investigated this activity using surface electromyography, in varied muscles and during a number of fu...

Background: Ankle plantarflexor muscle impairment contributes to asymmetrical postural control poststroke. Objective: This study examines the relationship of plantarflexor electromyography (EMG) with anterior-posterior center of pressure (APCOP) in people poststroke during progressive challenges to standing balance. Methods: Ten people poststroke a...

Objective: To compare the effects of active assisted wrist extension training, using a robotic exoskeleton (RW), with simultaneous 5 Hz (rTMS + RW) or Sham rTMS (Sham rTMS + RW) over the ipsilesional extensor carpi radialis motor cortical representation, on voluntary wrist muscle activation following stroke. Methods: The two training conditions...

Introduction: To investigate whether regional activation patterns in the vasti muscles differ between females with and without patellofemoral pain (PFP), and whether muscle activation patterns correlate with knee extension strength. Methods: Thirty-six females with PFP and 20 pain-free controls performed a standardized knee flexion-extension tas...

Movement is changed in pain, but the mechanisms remain unclear. Key questions are unresolved such as whether activation can be inhomogeneously distributed within a muscle in a manner that is specific to the location of noxious input. This study addressed this question using high density EMG to study regional redistribution of muscle activation with...

In this study, we investigated whether principal component analysis (PCA) and non-negative matrix factorization (NMF) perform similarly for the identification of regional activation within the human vastus medialis. EMG signals from 64 locations over the VM were collected from twelve participants while performing a low-force isometric knee extensio...

This study examined the task dependence of sensory inputs on motoneuron excitability by comparing the inhibitory postsynaptic potential (IPSP) evoked by stimulation of the sural nerve between a standing postural task (Free Standing) and a comparable voluntary isometric contraction performed in a supine position (Lying Supine). We hypothesized that...

Introduction: Previous evidence suggests the fibres of different motor units reside within distinct vastus medialis (VM) regions. Whether the activity of these motor units may be modulated differently remains unknown. Here we assess the discharge rate of motor units detected proximo-distally from VM to address this issue. Methods: Surface electr...

Objective: To compare neural drive, determined from motor unit firing rate, to the vastus medialis and lateralis in females with and without patellofemoral pain. Design: Cross-sectional study. Setting: University research laboratory. Participants: Females (N=56) 19-35 years old, 36 with patellofemoral pain and 20 controls. Interventions: N...

Ultrasound imaging was used to investigate vastus medialis (VM) architecture in 10 males and 10 females at different knee angles. Increase in muscle thickness occurs predominantly when the knee angle is changed from 0° (full extension) and 45° (p < 0.05); increases in VM pennation angle can be predominantly observed between 45° and 90° (p < 0.05)....

Transcranial magnetic stimulation (TMS) is a non-invasive method to measure corticospinal excitability of the primary motor cortex. However, motor evoked potentials (MEPs) elicited by TMS in a target muscle are variable; inconsistent MEPs may be due to overlapping cortical muscle representations and/or volume conduction from neighbouring muscles. T...

Key points: Regionalization of the stretch reflex, i.e. the notion that the activation of 1a afferents from a muscle region influences only the activation of motor units in the same region, has been demonstrated previously in animals but not in humans. Mechanical stretches applied to regions of vastus medialis as close as 10 mm apart resulted in r...

Objective: The purpose of this study was to examine simultaneously the level of physiological arousal and the postural response to external perturbations in people post-stroke compared to age-matched controls to build a more comprehensive understanding of the effect of stroke on postural control and balance self-efficacy. Methods: Participants s...

Introduction: The objective of this study was to determine whether motor evoked potentials (MEPs) elicited with transcranial magnetic stimulation and measured with conventional bipolar electromyography (EMG) are influenced by crosstalk from non-target muscles. Methods: MEPs were recorded in healthy participants using conventional EMG electrodes...

This study examined the contribution of muscle fiber orientation at different knee angles to regional activation identified with high-density surface electromyography (HDsEMG). Monopolar HDsEMG signals were collected using a grid of 13x5 electrodes placed over the vastus medialis (VM). Intramuscular electrical stimulation was used to selectively ac...

This chapter focuses on the most common form of feedback in physical rehabilitation: surface electromyograph (sEMG) biofeedback. It provides an overview of technical considerations and guidelines for the use of sEMG biofeedback and reviews some of its most common clinical applications. The principle of sEMG biofeedback is to provide the subject wit...

The reliability of triceps surae electromyographic responses to standing perturbations in people after stroke and healthy controls is unknown. High-Density surface Electromyography (HDsEMG) is a technique that records electromyographic signals from different locations over a muscle, overcoming limitations of traditional surface EMG such as between-...

Background: High‐frequency repetitive transcranial magnetic stimulation (rTMS) can alter motor cortical excitability following stroke. Similarly, robotic‐assisted intensive movement practice has been advanced as a therapy for stroke. However, the impact of these combining these interventions on muscle activation is not known. This pilot study inves...

To investigate if muscle fibers innervated by single motorneurons are confined in small subvolumes of the vastus medialis and if motor unit fiber orientation depends on their position within the muscle. Single motor units were identified from a grid of surface electrodes. The size of their surface representation and fiber orientation were extracted...

In this study we investigated whether the spatial distribution of surface electromyographic (EMG) amplitude can be used to describe the activation of muscle portions with different biomechanical actions. Ten healthy subjects performed isometric contractions aimed to selectively activate a number of forearm muscles or muscle subportions. Monopolar e...

The aim of this study was to investigate the position of the innervation zone (IZ) of the vastus medialis (VM) and its effect on the electromyographic (EMG) amplitude and mean frequency estimates. Eighteen healthy subjects performed maximal isometric knee extensions at three knee angles. Surface EMG signals were collected by using a 16 × 8 electrod...

Aim. It is currently unknown whether preferential activation of the distal portion of the vastus medialis can be obtained by performing isometric knee extension exercises at selected knee angles and force levels. The aim of this study was to assess whether preferential activation of muscle sub-portions within the vastus medialis occurs at different...

Muscle fiber conduction velocity (CV) is commonly estimated from surface electromyograms (EMGs) collected with electrodes parallel to muscle fibers. If electrodes and muscle fibers are not located in parallel planes, CV estimates are biased towards values far over the physiological range. In virtue of their pinnate architecture, the fibers of muscl...

The aim of this work is to show how changes in surface electromyographic activity (sEMG) during a repetitive, non-constant force contraction can be detected and interpreted on the basis of the amplitude distribution provided by high-density sEMG techniques. Twelve healthy male subjects performed isometric shoulder elevations, repeating five times a...

Myoelectric fatigue typically manifests as variations in the amplitude and spectrum of surface electromyograms (EMGs). Interestingly, these variations seem to be represented locally in different muscles. In this study, we ask whether such a regional distribution of myoelectric fatigue extends to the medial gastrocnemius (MG) muscle. If the MG muscl...

The propagation of action potentials might be detected in surface electromyograms (EMGs), exclusively when an array of electrodes is positioned parallel to the muscle fibers. The medial gastrocnemius (MG) muscle, however, is pinnate. Its oblique architecture does not allow for the surface electrodes to run parallel along its fascicles. Nevertheless...