Status of surface electromyography assessment as part of clinical gait analysis in the management of patients with cerebral palsy - Outcomes of a Delphi process.

Background: The assessment of gait disorders in patients with neuromotor conditions, such as cerebral palsy (CP), has been a focus of clinical and research attention, with electromyography (EMG) offering a nuanced understanding of neurological and neuromuscular disorders. However, the interpretation of EMG data in the context of gait analysis remains challenging due to the complexity of neuromotor dynamics and variability in assessment methodologies.

Research Question: To which consensus can we get in a group of experts in the fields of neurological and neuromuscular disorders, biomechanics, and clinical gait analysis to establish standardized protocols and a common language for the measurement and analysis of EMG data in gait disorders, particularly in people living with CP?

Methods: A three-round Delphi process was conducted from February to September 2023 to gather opinions of 53 experts on the use of surface EMG data during gait in the context of CP.

Rectus femoris electromyography signal clustering: Data-driven management of crouch gait in patients with cerebral palsy.

This study aimed to investigate how electromyography (EMG) cluster analysis of the rectus femoris (RF) could help to better interpret gait analysis in patients with cerebral palsy (CP). The retrospective gait data of CP patients were categorized into two groups: initial examination (E1, 881 patients) and subsequent examination (E2, 377 patients). Envelope-formatted EMG data of RF were collected.

Postactivation Potentiation and the Asynchronous Action of Muscular and Neural Responses.

Purpose: This study examined the underlying mechanisms of postactivation potentiation and the time course of muscular- and neural-related variables.

Methods: Fourteen trained males executed 4 sets of six 6-second maximum isometric conditioning plantar flexions, with 15 seconds and 2 minutes of interval between the contractions and sets, respectively. Peak twitch torque (TT), rate of torque development, time to peak torque, half relaxation time, and the neural-related variables of H-reflex and electromyogram, normalized to the maximum M-wave (H/M and RMS/M, respectively), were evaluated, as well as the level of the voluntary activation, assessed by the twitch interpolation technique.

Protocols Targeting Afferent Pathways via Neuromuscular Electrical Stimulation for the Plantar Flexors: A Systematic Review.

This systematic review documents the protocol characteristics of studies that used neuromuscular electrical stimulation protocols (NMES) on the plantar flexors [through triceps surae (TS) or tibial nerve (TN) stimulation] to stimulate afferent pathways. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, was registered to PROSPERO (ID: CRD42022345194) and was funded by the Greek General Secretariat for Research and Technology (ERA-NET NEURON JTC 2020). Included were original research articles on healthy adults, with NMES interventions applied on TN or TS or both.

Optimal Drop Height in Prepubertal Boys Is Revealed by the Performance in Squat Jump.

Drop jump (DJ) performance gain with increasing drop height is well documented in adults, but there is still no clear evidence of such gain in children. This study aimed to examine the differences in DJ performance gain in male adults and prepubescent boys by comparing drop heights tailored to each individual's performance and expressed as a percentage of their squat jump (SJ) performance. Fifteen boys (9-11 y) and 15 men (19-27 y) executed DJs from drop heights that were set at 75%, 100%, 125%, and 150% of their best performance in SJ (DJ, DJ, DJ, and DJ, respectively).

Temporal modulation of H-reflex in young and older people: Acute effects during Achilles tendon vibration while standing.

Purpose: Examining how timely is sensory input processed and regulated after a perturbation while standing, is a key element to understand postural control, especially in people with balance deficits, such as older adults. In this study, we investigated the age-related temporal modulations in spinal excitability, by measuring the soleus H-reflex within the first 250 ms after switching on (V-ON) and off (V-OFF) a pair of vibrators, placed over the Achilles tendons.

Methods: Twenty young (25.

Neuromuscular, kinetic and kinematic differences in drop jumping between male adolescents with and without intellectual disability.

Background: Individuals with intellectual disability (ID) have lower performance in vertical jumps compared to individuals without ID. Training programmes including drop jump (DJ) exercises to gap this deficit are required. However, there is a lack of knowledge on biomechanical variables may influence DJ performance in young people with ID.

Resilience of visually guided weight shifting to a proprioceptive perturbation depends on the complexity of the guidance stimulus.

Background: Whole-body tracking of visual motion cues is used in balance training to improve weight shifting ability in old age and sports.

Research Question: How tracking of a complex (pink noise) and a periodic visual target motion during anteroposterior weight shifting affects postural and muscle responses to unilateral hip vibration.

Methods: Twenty-six participants performed 160 anteroposterior weight shifting cycles while tracking the vertical motion of a visual target, concurrently receiving Center of Pressure (CoP) feedback.

Electromyographic responses to unexpected Achilles tendon vibration-induced perturbations during standing in young and older people.

This study aimed to investigate age-related differences in electromyographic (EMG) responses to unexpected Achilles tendon vibration (ATV) perturbations while standing blindfold. ATV with variable and random duration (12-15 s) and rest periods (20-24 s) was applied on 18 young and 16 older volunteers. The anterior/posterior center of pressure (CoP) and the soleus (SOL) and tibialis anterior (TA) EMG were analyzed for 1 s before and 8 s after the ATV onset and offset.

Standing on unstable surface challenges postural control of tracking tasks and modulates neuromuscular adjustments specific to task complexity.

Understanding the modulations of motor control in the presence of perturbations in task conditions of varying complexity is a key element towards the design of effective perturbation-based balance exercise programs. In this study we investigated the effect of mechanical perturbations, induced by an unstable surface, on muscle activation and visuo-postural coupling, when actively tracking target motion cues of different complexity. Four postural tasks following a visual oscillating target of varying target complexity (periodic-sinusoidal vs.

Altered Drop Jump Landing Biomechanics Following Eccentric Exercise-Induced Muscle Damage.

Limited research exists in the literature regarding the biomechanics of the jump-landing sequence in individuals that experience symptoms of muscle damage. The present study investigated the effects of knee localized muscle damage on sagittal plane landing biomechanics during drop vertical jump (DVJ). Thirteen regional level athletes performed five sets of 15 maximal eccentric voluntary contractions of the knee extensors of both legs at 60°/s.

Age induced modifications in the persistency of voluntary sway when actively tracking the complex motion of a visual target.

Movement persistency, reflected in systematic cycle to cycle fluctuations of a rhythmical task such as walking or voluntary sway, is compromised with increasing age, making older adults more susceptible to falls. In the present study, we tested whether it is possible to improve rhythmic voluntary sway persistency in old age by actively tracking the complex (i.e.

Construct validity of gymnastics-specific assessment on the neuromuscular function of shoulder flexor and extensor muscles.

The present study examined the construct validity of gymnastics-specific measurements of the shoulder flexor and extensor neuromuscular function. Fifteen male gymnasts and 18 male physical education (PE) students participated voluntarily. The electromyogram (EMG) of 3 flexor and 3 extensor shoulder muscles was assessed during isometric (45, 90, and 135º) and isokinetic (concentric and eccentric 60, 180, and 300º/s) shoulder flexion/extension.

Kinetic and Kinematic Changes in Vertical Jump in Prepubescent Girls After 10 Weeks of Plyometric Training.

Purpose: To examine the effect of a 10-week plyometric training (PT) on the kinematic and kinetic properties of prepubescent girls during squat jump, countermovement jump, and drop jumps.

Methods: Twenty-four untrained girls (aged 9-11 y) were assigned to a training group (TG) and a control group. The TG followed twice a week PT for 10 weeks.

Swaying slower reduces the destabilizing effects of a compliant surface on voluntary sway dynamics.

The ability to control weight shifting (voluntary sway) is a crucial factor for stability during standing. Postural tracking of an oscillating visual target when standing on a compliant surface (e.g.

Exercise-induced fatigue in young people: advances and future perspectives.

Purpose: In recent decades, the interest for exercise-induced fatigue in youth has substantially increased, and the effects of growth on the peripheral (muscular) and central (neural) mechanisms underpinning differences in neuromuscular fatigue between healthy children and adults have been described more extensively. The purpose of this review is to retrieve, report, and analyse the findings of studies comparing neuromuscular fatigue between children and adults. Objective measures of the evaluation of the physiological mechanisms are discussed.

Muscle Twitch Torque During Two Different in Volume Isometric Exercise Protocols: Fatigue Effects on Postactivation Potentiation.

Xenofondos, A, Bassa, E, Vrabas, IS, Kotzamanidis, C, and Patikas, D. Muscle twitch torque during two different in volume isometric exercise protocols: fatigue effects on postactivation potentiation. J Strength Cond Res 32(2): 578-586, 2018-The purpose of this study was to quantify the effect of the contraction duration of 2 isometric exercise protocols on the postactivation potentiation of 14 well-trained men (age: 22.

The acute effects of an intense stretch-shortening cycle fatigue protocol on the neuromechanical parameters of lower limbs in men and prepubescent boys.

The study examined the differences between boys and adults after an intense stretch-shortening cycle fatigue protocol on neuromechanical parameters of the lower limb. Thirteen boys (9-11 years old) and 13 adult men (22-28 years old) were tested for maximal isometric voluntary knee extension torque and drop jump (DJ) performance from 30 cm before and immediately after a fatigue protocol, consisted of 10 × 10 maximum effort vertical jumps. Three-dimensional kinematics, kinetics and electromyographic (EMG) parameters of the lower extremities muscles were recorded during DJs before and after the fatigue test.

Soleus H-reflex modulation during balance recovery after forward falling.

Introduction: Our purpose was to examine the Hoffmann reflex (H-reflex) during balance recovery after a simulated forward fall from 2 different inclination angles.

Methods: The soleus H-reflex of 15 healthy adults was measured in 2 different leaning positions (exerting a horizontal force at 15% and 30% of body weight, respectively), with no release (Int0) and at 2 different intervals (Int1, Int2) after the release (∼45 and ∼65 ms, respectively).

Results: During Int2, the H-reflex, which was evoked before the onset of the soleus electromyography, was significantly higher than the H-reflex induced 20 ms earlier (Int1).

The effect of dropping height on jumping performance in trained and untrained prepubertal boys and girls.

Plyometric training in children, including different types of jumps, has become common practice during the last few years in different sports, although there is limited information about the adaptability of children with respect to different loads and the differences in performance between various jump types. The purpose of this study was to examine the effect of gender and training background on the optimal drop jump height of 9- to 11-year-old children. Sixty prepubertal (untrained and track and field athletes, boys and girls, equally distributed in each group [n = 15]), performed the following in random order: 3 squat jumps, 3 countermovement jumps (CMJs) and 3 drop jumps from heights of 10, 20, 30, 40, and 50 cm.

Postactivation potentiation effects after heavy resistance exercise on running speed.

The purpose of this study was to investigate the postactivation potentiation effect after a heavy resistance stimulus (HRS) on running speed (RS). Fifteen amateur team game players (basketball, volleyball, handball, and soccer players), ages 18-23 years running the 30-m dash and the intermediate phase of 0-10 and 0-30 m sprints, were used to evaluate RS. Resistance training consisted of 10 single repetitions at 90% of 1 repetition maximum.