Following a lateral ankle sprain, chronic ankle instability (CAI) subjects show recurrent episodes of giving way, while copers do not exhibit giving way and overcome the challenging condition of postural control. During gait initiation (GI), individuals with CAI reveal shorter center of pressure (COP) displacement and earlier muscle activity compared with healthy controls. Copers have not been previously compared with healthy controls and individuals with CAI during GI. The study design was cross-sectional. Sixty participants (20 CAI, 20 copers, and 20 healthy controls) with a right (dominant) limb injury participated in the study based on inclusion and exclusion criteria. The short form of the Tampa Scale of Kinesiophobia was filled out. Participants performed GI with the nonaffected leg on the force plate that was synchronized with Electromyography Megawin for 2 strides. GI was divided into 3 phases based on COP excursion (S1, S2, and S3). Onset time and electromyography activity of both soleus and tibialis anterior muscles were analyzed along with maximum and mean excursion and velocity of COP excursion in the anterior-posterior and medial-lateral directions and the total phases of GI. The results indicated that the copers had a significantly higher peak of COP excursion in the medial-lateral direction during S2 (P = .029), S3 (P = .018), and total phases (P = .018) of GI compared with the individuals with CAI. Additionally, individuals with CAI showed earlier activation of the right soleus compared with healthy controls (P = .022). There was a significant difference in short form of the Tampa Scale of Kinesiophobia scores between individuals with CAI and other groups (P < .001). The findings demonstrated that individuals with CAI had earlier soleus activation and supraspinal alteration compared with controls. Copers who had lower Tampa Scale of Kinesiophobia scores exhibited an increased peak of COP excursion in the medial-lateral direction during GI compared with individuals with CAI.

Inter-session reliability of prefrontal cortex functional near-infrared spectroscopy measures during dual-task walking protocols of different duration in stroke survivors and healthy controls.

Anticipatory postural adjustments (APAs) are crucial for maintaining postural stability during voluntary movements such as gait initiation. While APAs have been extensively studied in forward stepping, little is known about their characteristics during turning initiation. This study aimed to identify the characteristics of (i) APAs and subsequent first steps during turning in older adults (OA) and (ii) compare them to people with Parkinson's disease (pwP). Twenty-two pwP (tested on medication) and 17 OA performed self-paced 360˚ turns which were embedded in a complex walking task. APAs and first step characteristics were recorded using motion capture and force plate data. For pwP, APAs in turning (unloading phase) were found to be primarily mediolateral, and of significantly reduced amplitude (median = 2.5, 95% CI[0.0053; 0.0089]) in comparison to OA (median = 5.0, 95% CI[0.0073; 0.0181]). Unlike OA there was no significant association between APAs and step characteristics. These findings suggest that APAs during turning are significantly impaired in pwP, even when tested ON medication, and that this impairment may contribute to the turning difficulties often experienced by this population. Overall, these results have potential implications for clinical assessments and rehabilitation interventions, emphasising the need to tailor strategies to address turning challenges pwP face in their daily life.

A comparative study of gait pattern characteristics between individuals with multiple sclerosis and healthy individuals during anticipatory postural adjustment and gait initiation: A scoping review.

Network-wide morphometric organization deficits and transcriptomic correlates in Parkinson's disease with freezing of gait: A morphometric inverse divergence study.

Circumduction gait in stroke patients, a compensatory movement involving pelvic hike and femoral abduction, increases energy cost. However, longitudinal studies on its mechanism during the acute phase are lacking. This study longitudinally investigated changes in the paretic femoral abduction angle during gait in acute stroke patients and identified related factors. Twenty-two stroke patients were assessed twice: at gait initiation and 10-14 days later. Gait kinematics during a 3 m walk were measured using a depth sensor, and physical functions (SIAS) were evaluated. Changes were analyzed using paired t-tests and correlation analyses. Spatiotemporal parameters improved significantly. Kinematically, paretic femoral abduction (p = 0.049) and paretic pelvic hike (p = 0.025) significantly decreased, while maximum paretic knee flexion during swing (p = 0.026) increased. The decrease in femoral abduction correlated positively with the decrease in pelvic hike (r = 0.55) and negatively with the improvement in paretic ankle motor function (SIAS) (ρ = -0.49). The decrease in pelvic hike correlated negatively with the improvement in paretic knee motor function (SIAS) (ρ = -0.43). These results suggest that in acute stroke patients, the recovery of paretic ankle and knee motor functions leads to a reduction in compensatory femoral abduction and pelvic hike, respectively. This study provides insights for re-evaluating compensatory movements as an adaptive phenomenon during recovery, not merely as abnormal movements.

Background/Objectives: The benefits of physical activity (PA) do not depend on the PA level alone but also on sedentary behavior (SB). The interaction between PA and SB (i.e., PA–SB interplay) is important to determine one’s health status. This study explored the effect of PA–SB interplay on balance and gait in healthy young adults. Methods: Healthy young adults (n = 133, 18–35 yrs) were placed in four PA–SB interplay groups (according to their sitting duration and physical activity duration) using the American College of Sports Medicine PA guidelines (i.e., sedentary active [&gt;6 h/day, &gt;150 min/week], sedentary inactive [&gt;6 h/day, &lt;150 min/week], physically active [&lt;6 h/day, &gt;150 min/week], and physically inactive [&lt;6 h/day, &lt;150 min/week]). In this cross-sectional study, participants’ balance and gait were assessed with inertial measurement units placed on seven bodily sites. In this exploratory study, significance level was set at p &lt; 0.1. Results: Sway acceleration RMS during the eyes closed on stable surface balance test showed a statistically significant difference among the PA–SB interplay groups (p = 0.055) which was found between sedentary active and physically inactive (p = 0.066). Anticipatory postural adjustment (APA) duration during gait showed a statistically significant difference (p = 0.010) which was found between sedentary inactive and physically active (p = 0.019) and between sedentary active and physically active (p = 0.026). Conclusions: PA–SB interplay influences static (sway acceleration RMS) and dynamic (APA duration) balance of healthy young adults. Findings suggest that somatosensory processing during balance and gait initiation are significantly impacted by PA–SB interplay.

This study investigated the impact of real-time laser-guided visual cues on spatiotemporal gait parameters during initiation and termination in people with Parkinson’s (PwP). Fifteen PwP walked a 5-m path under uncued and laser-cued conditions while gait kinematics and center of pressure (CoP) data were collected. Results revealed that laser-guided visual cues significantly increased anterior-posterior CoP displacement during the propelling phase of gait initiation (p = .016) and improved dynamic stability, evidenced by reduced lateral asymmetry (p = .007) and decreased fractal dimension of lateral gait variability (p = .001). Conversely, step time increased (p = .005) and step velocity decreased (p < .001) with cueing, while step length remained unchanged. No significant effects of cueing were observed during gait termination. These findings suggest that laser-guided visual cues enhance gait initiation in PwP by promoting propulsion and stability, likely by facilitating an external focus of attention and improving anticipatory postural adjustments. The lack of effect on gait termination may reflect differing neural control mechanisms. This study contributes to the understanding of laser-guided visual cueing mechanisms in PwP gait and supports its potential as a targeted intervention for improving functional mobility, particularly during the challenging phase of gait initiation.

To provide an overview of alterations in anticipatory postural adjustments (APAs) during gait initiation (GI) and its possible clinical applicability in people with Parkinson's disease (pwPD). A systematic search was conducted in PubMed and Web of Science using the terms: "Parkinson's disease" AND "postural adjustment" AND ("gait initiation" OR "step initiation"). Variables commonly used to assess APAs, including center of pressure (CoP) displacement and electromyography (EMG), were extracted. Study quality was assessed with the Newcastle-Ottawa Scale. Fourteen studies including 453 pwPD and 287 healthy subjects (HS) were reviewed. People with Parkinson's disease (PD) consistently exhibited smaller and slower CoP displacements in both anteroposterior and mediolateral directions, together with prolonged APAs durations. EMG findings indicated delayed onset and reduced amplitude, particularly in tibialis anterior and hip abductors, muscles pivotal for safe GI. Alterations were linked to disease severity and postural instability, with more pronounced changes in pwPD with freezing of gait (FoG). APAs-derived metrics showed sensitivity to subtle motor deficits even in early disease stages. The reviewed literature demonstrates bradykinetic and hypokinetic APAs during GI in pwPD. GI-based measures may complement functional assessment for postural stability, gait, and fall risk, and have potential value for rehabilitation strategies such as external cueing. Levodopa improves but does not normalize APAs. Standardized, clinically feasible GI protocols are required to define meaningful thresholds and responsiveness so that APA-derived measures can be translated into routine clinical practice.

Anticipatory postural adjustments during multidirectional gait initiation with body turning among healthy young men.

Early longitudinal monitoring of motor development in preterm infants: is gait initiation enough?

Personalised gait retraining for medial compartment knee osteoarthritis: a randomised controlled trial.

With the advent of an aging society, the lack of physical activity has become a major concern, leading to various age-related diseases. To prevent such issues, research on wearable robots aimed at improving gait has been actively pursued. Among them, exoskeleton robots, a widely used approach, require an accurate understanding of the user’s gait cycle for effective control. Various studies have explored gait cycle detection and prediction methods depending on the type of gait robot platform and the use of sensors. However, a major challenge in gait cycle prediction algorithms remains the issue of nonlinear predictive trajectories. In the study, a robotic hip exoskeleton (RHE) was utilized to implement an enhanced gait phase estimation (GPE) algorithm integrated with a muscle support system. Participants were divided into two groups (Group A and Group B) based on their initial gait performance, and the effectiveness of gait rehabilitation training was evaluated. The results showed that in the 10-meter walk test (10MWT), walking time decreased by approximately 5% in Group A and 27% in Group B. In the 6-minute walk test (6MinWT), walking distance increased by approximately 1% in Group A and 14% in Group B. Group B, which had lower initial gait performance, showed a greater gait performance improvement rate compared to Group A, which had higher initial gait performance. Through the gait performance results of the two groups, the applicability of the GPE based muscle support algorithm was confirmed.

Background:Impaired gait initiation is a debilitating motor symptom in people with Parkinson’s disease (PD). During self-paced (uncued) gait initiation, anticipatory postural adjustments (APAs) are often absent or attenuated, and the first steps are abnormally short. External sensory cues can significantly improve APAs.Objective:The effect of external cueing on lower limb muscle activation during gait initiation, compared to self-initiated steps, was examined in people with PD and healthy older adults (HOA).Methods:Ground reaction forces, center of pressure excursions, and lower-limb surface electromyographic profiles (in seven bilateral muscles) were examined in 32 individuals with PD (off-medication) and 10 age-matched HOA during the APA and first step of self-paced or acoustically cued gait initiation.Results:Anterior (tibialis anterior, vastus lateralis, rectus femoris) and gluteus medius muscles were primarily activated during the early phases of gait initiation, while later phases predominantly involved posterior (soleus, gastrocnemius, biceps femoris) and gluteus medius activations. Cueing facilitated anterior muscles and suppressed posterior muscle activity in both groups, however, activation patterns in PD were not restored to HOA levels. Instead, the PD group had lower early activity during the APA (compared to HOA) and higher late activity.Conclusions:Cueing increased anterior muscle activation during gait initiation, rather than evoking a global gain across muscles and timings, demonstrating that cueing predominantly facilitates neural circuitry critical for early APA phases. People with PD showed enhanced late phase activity, probably to compensate for ineffective APAs, and thus have a stronger need to facilitate cue-evoked improvements.

Effects of a reactive task on gait initiation in elderly individuals with mild cognitive impairment.

Parkinson’s disease (PD) disrupts the intricate cognitive, emotional and sensorimotor circuits required for movement. In a recent study, we observed that fear-related embodied stimuli could enhance motor responses in early stage persons with PD (PwPD), potentially by activating neural compensatory mechanisms. In this observational study, we implemented a sensor-based ‘Go/No-go’ gait initiation task involving a response to emotional facial expressions—fear, happiness and neutral facial expressions—to elucidate whether and how emotional cues may drive compensatory mechanisms for motor performance in middle-stage PD. Furthermore, we investigated whether these mechanisms differ between PwPD exhibiting tremor-dominant (TD) or postural instability and gait disorders (PIGD) motor subtypes. By comparing gait initiation parameters between PD participants and age-matched healthy controls, we found that emotional stimuli reduced the duration of anticipatory postural adjustments and the step execution time across both groups, indicating a robust motor advantage. Specifically, happiness elicited a more pronounced advantage than fear, though PwPD displayed a diminished benefit relative to controls. Intriguingly, individuals with the PIGD subtype showed a weaker motor advantage for ‘happiness’ than those with the TD subtype, suggesting subtype-specific differences, possibly reflecting different underlying neural circuitry. Collectively, our findings reveal that while emotional cues generally facilitate gait initiation, fear and happiness exhibit distinct modulatory effects in PD. Compared to our earlier findings, the fear-related motor benefit appears to decline with disease progression, while the happiness-related advantage varies considerably across PD subtypes. These insights highlight the nuanced interplay between emotion and motor control in PD and suggest the use of a cognitive-emotional-sensorimotor integration task as a sensitive predictor for differentiating PD motor subtypes.

The counter-rotating mechanism makes a substantial contribution to balance-movement coordination during the anticipatory period of gait initiation.

Effect of exercise interventions on gait initiation in individuals with knee osteoarthritis: a double-blind, randomized controlled trial.

ABSTRACTBackgroundChronic ankle instability (CAI) disrupts postural stability after ankle sprains and inadequate treatment. Gait initiation (GI), governed by central nervous system (CNS) patterns, is used to evaluate stability. Muscle synergy, which reflects coordinated activations, reveals neuromuscular control. This study investigates lower limb muscle synergies during GI in individuals with and without CAI to understand their neuromuscular strategies.DesignCross‐sectional study.SettingLaboratory.MethodThis study involved 20 participants, 10 healthy men and 10 patients with CAI. Six electrodes were applied per the SENIAM guidelines, and markers were set according to the cluster model. The participants initiated gait after an auditory cue was presented on a force plate. OpenSim simulated a musculoskeletal model using kinematic and muscle activity data. Muscle synergies were analyzed via HALS in MATLAB. Statistical tests, including Wilcoxon and one‐way ANOVA, were conducted in SPSS with p < 0.05 as the significance threshold.ResultsThe number of muscle synergies was not significantly different between the healthy and CAI groups (p > 0.05). However, muscle weight differed significantly between synergies 1 and 2 (p < 0.05). In synergy 1, the TA had greater weighting in the CAI group, whereas synergy 2 had higher RF and GM_L weightings in the CAI group. Synergy 3 revealed greater PL weight in the control group (p < 0.05).ConclusionIn CAI, PL muscle weakness is offset by the TA, RF, and GM_L muscles resulting in altered ankle strategies during gait instability. This compensation disrupts motor chains, increases movement complexity, and involves the CNS, framing CAI as a global movement issue rather than a localized problem.

Background and Purpose Parkinson’s impairs movement control and proprioception. This pilot randomized controlled trial investigated whether anodal transcranial direct current stimulation (a-tDCS) combined with proprioceptive exercises improves these functions in people with Parkinson’s. Methods Twenty-four people with Parkinson’s were randomly assigned (1:1) to either active a-tDCS (2mA, 20 minutes, 3 sessions/week for 2 weeks) or sham stimulation, followed by standardized proprioceptive training. The primary outcome was ankle joint proprioceptive acuity. Secondary outcomes included postural sway, gait initiation parameters, and quality of life. Participants were blinded to group allocation. Results The active a-tDCS group showed significantly greater improvement in ankle joint repositioning error compared to the sham group (mean difference −2.9 degrees, 95% CI [−3.1, −2.7]; P = .012). Postural sway (elliptical sway area, eyes closed) was also significantly reduced in the active a-tDCS group (−2.6 cm², 95% CI [−4.6, −0.6]; P = .038). Gait initiation time decreased in both groups, but only the active a-tDCS group showed a significant reduction in step time (−168 ms, 95% CI [−175, −160]; P = .005). No significant between-group difference was found in quality of life (P = .687). Discussion and Conclusions Multiple sessions of a-tDCS combined with proprioceptive exercises explored preliminary evidence of enhanced proprioceptive acuity and postural control in people with Parkinson’s. Gait initiation also improved with a-tDCS. All a-tDCS sessions were well-tolerated by participants, with no adverse effects reported. Further research is needed to explore long-term effects and underlying mechanisms. This pilot study provides preliminary evidence for a-tDCS as a potential adjunctive therapy, though larger trials are needed to confirm clinical efficacy. Clinical trial registration code: IRCT20230820059201N2 (Iranian Registry for Clinical Trials) Clinical trial registration URL: https://irct.behdasht.gov.ir/trial/76791 Clinical trial registration Name: Effect of Adding Trans-Cranial Direct Current Stimulation on Supplementary Motor Area to Exercise Therapy on Proprioception Acuity, Postural Control, Initiation of Gait, and Brain Cortical Activity in People with Parkinson’s