The Effectiveness of Proprioceptive Training for Improving Motor Performance and Motor Dysfunction: A Systematic Review

Effects of proprioceptive training on sports performance: a systematic review

BACKGROUND

Proprioception, the ability to sense the body's position and movement, is essential for athletic performance and physical well-being. The literature highlights the importance of proprioceptive training in rehabilitation, sports performance, injury prevention, and motor function enhancement. Targeted training programs can improve balance, coordination, motor learning, and overall physical performance. This systematic review aimed to examine the effects of proprioceptive training methods on sports and athletic performance.

METHODS

A comprehensive search was conducted using the Web of Science, PubMed, and Scopus databases, and a literature review was performed based on the PICO criteria outlined in the abstract and title.

RESULTS

Following the search, 178 articles were identified using relevant keywords, of which 19 directly addressed sports performance and were included in this study. The findings revealed that proprioceptive training had a positive influence on various aspects of athletic performance, including physiological capacity, balance, explosive strength, speed, agility, postural stability, knee joint position sense, muscle activation, reduction of chronic joint instability, dribbling, passing, and technical ball-control skills.

CONCLUSIONS

These results indicate that proprioceptive training can be an effective strategy for experts and coaches to enhance athletes' physical performance. Primarily, proprioceptive exercises should be used inside and outside the training sessions to enable athletes to interact more effectively with their bodies, reduce the risk of injury, and improve power transfer.

Effect of Proprioceptive Training Compared With Other Interventions for Upper Limb Deficits in People With Parkinson Disease: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This systematic review and meta-analysis aimed to determine the efficacy of proprioceptive training on hand dexterity, upper limb function, and quality of life (QoL) in people with Parkinson disease (PD) compared with no or other active interventions.

DATA SOURCES

Medline PubMed, Cochrane Library, CINAHL, PEDro, and Web of Science databases were searched to identify published studies until February 2023.

STUDY SELECTION

Peer-reviewed English publications of randomized controlled trials (RCTs) of proprioceptive training conducted among people with PD.

DATA EXTRACTION

Study characteristics, exercise program type and dosage, outcome of interest, and between-group comparisons of post-test results of intervention and comparison groups.

DATA SYNTHESIS

Eight RCTs were included, involving 344 people with PD. Six RCTs contributed to meta-analyses. There was very low certainty of evidence that proprioceptive training may improve dominant hand (standard mean difference [SMD] 0.34, 95% CI 0.08-0.60, P=.01) and non-dominant hand (SMD 0.36, 95% CI 0.10-0.63, P<.01) fine motor dexterity, and dominant hand gross manual dexterity (SMD 1.73, 95% CI 0.30-3.16, P=.02), following 2-8 weeks of proprioceptive training. There was no evidence of effects on non-dominant hand gross manual dexterity, upper limb function, and QoL after proprioceptive training.

CONCLUSIONS

Findings regarding the effect of proprioceptive training on hand dexterity in the short-term are inconclusive. The small sample size likely limited effect detection. Future large RCTs should compare proprioceptive training with no intervention and perform comprehensive biomechanical analysis to gain a clearer idea of its effects. Incorporating longer-duration proprioceptive training programs is also recommended to investigate long-lasting effects.

Treating Dystonia in a Soccer Player Through an Integrated Rehabilitative Approach: A Case Report

CONTEXT

Sport-related dystonia is a rare form of activity-specific dystonia that can severely impair an athlete's ability to perform. Due to a lack of data on the condition, it is difficult to diagnose and often overlooked, and no gold standard treatment has yet been defined.

CASE PRESENTATION

We present a rare and challenging case of sport-related dystonia that affected a 24-year-old male professional soccer player. The patient presented with severe rigidity and dystonia of the right lower-extremity, particularly the ankle and foot. The symptoms set on >1 year prior to the presentation to our outpatient clinic. He began to complain of stiffness and difficulty moving his lower limbs, especially his right leg, initially when playing soccer, but then also when walking normally. On presentation, he was unable to run and walked with difficulty, supporting his body weight only on the outside of his right foot. He also reported a motor trick and reverse motor trick involving the oral musculature in order to move his lower limb more freely.

MANAGEMENT AND OUTCOMES

An integrated rehabilitation approach based on postural rehabilitation, neuromuscular rehabilitation, and dental intervention was used to successfully treat this condition. The approach included: (1) postural rehabilitation with the Mézières-Bertelè method to reduce muscular stiffness, (2) neuromuscular re-education with Tai Chi exercises and electromyography-guided biofeedback, and (3) dental intervention and swallowing rehabilitation to limit impaired oral habits (due to the relationship between his impaired lower limb movements and motor tricks of the oral musculature). After 7 months of integrated rehabilitation, the patient returned to professional soccer.

CONCLUSIONS

This case report highlights the potential efficacy of an integrative rehabilitation approach for sports dystonia, particularly in cases where traditional treatments may not be effective. Such an approach could be considered a valuable option in the management of this rare, but debilitating, condition in athletes. Further research is needed to assess the effectiveness of this approach in larger populations.

The Effect of Single-Session Stimulating Massage on the Knee Joint Position Sense in Healthy Older Adult Men: A Randomized Crossover Trial

Background

Proprioception is critical for older adults to maintain their balance and prevent falling. However, massage is a convenient intervention that its beneficial effect on the proprioception is suggested.

Purpose

This study aimed to determine whether one session of stimulating massage of the muscles around the knee joint improves position sense in older adult men.

Methods

Twenty healthy older adults participated in this blind, randomized, crossover trial. The two treatment phases were massage and rest. The washout period between interventions was a 1-week interval. The massage protocol was as follows: deep effleurage, petrissage, and tapotement for 5 minutes for the anterior (tensor fascia lata, quadriceps, sartorius, and gracilis) and posterior (hamstrings) muscles of the knee (10 minutes in total).

Results

Outcome measures were absolute, constant, and variable errors (AE, CE, and VE). Participants were assessed immediately before and after the intervention by a blinded investigator. Independent t-tests were used for statistical analyses. Massage reduced absolute error (2.77°, p = 0.01).

Conclusion

The finding of this study confirms the beneficial impact of the massage on the joint position sense in healthy older adult men.

Influence of compression garments on proprioception: A systematic review and meta-analysis

Compression garments (CGs) are commonly used in rehabilitation and sports contexts to enhance performance and speed up recovery. Despite the growing use of CGs in recent decades, there is no unanimous consensus on their overall influence on joint proprioception. In this current meta-analysis, we aim to fill this knowledge gap by assessing the impact of CGs on joint proprioception. We conducted a literature search across seven databases and one registry. Ultimately, we included 27 studies with 671 participants. The meta-analysis revealed that wearing CGs resulted in a significant reduction in absolute error during joint position sensing (Hedges' g: -0.64, p = 0.006) as compared to no CGs. However, further analyses of variables such as constant error (p = 0.308), variable error (p = 0.541) during joint position sense tests, threshold to detect passive motion (p = 0.757), and active movement extent discrimination (p = 0.842) did not show a significant impact of CGs. The review also identified gaps in the reporting of certain outcomes, such as parameters of CGs, reporting of performance, individual-reported outcomes, and lack of placebo comparators. Consequently, this review provides guidelines for future studies that may facilitate evidence-based synthesis and ultimately contribute to a better understanding of the overall influence of CGs on joint proprioception.

Influence of short bouts of stair climbing on young adults during prolonged sitting on posture, discomfort, and musculoskeletal performance outcomes: a counterbalanced pilot randomised crossover trial

Prolonged sitting is postulated to influence musculoskeletal performance (cervical flexor endurance, balance, and agility), discomfort and alter cervical spine angles during work-based computer use. Stair climbing breaks may be a great addition at typical and home offices however remain unexplored for its impact on musculoskeletal performance. In our counterbalanced pilot crossover trial, 24 adults were randomised to three interventions: (1) prolonged sitting, (2) interrupted by 2 min of self-paced, and (3) externally paced stair climbing for 2 h. Cervical spine angles were measured every 30 min while balance, agility, endurance, and discomfort were assessed before and after 120 min. Stair climbing interruptions have favourable effects on agility (F = 8.12, p = 0.009, ηp2 = 0.26) and musculoskeletal discomfort, but failed to improve other musculoskeletal outcomes associated with prolonged sitting. Brief stair climbing interruptions are effective in improving discomfort and agility while pragmatic trials are warranted for translated effects.

Impaired motor skills and proprioceptive function in Mandarin-speaking children with developmental language disorder

This study examined proprioceptive acuity and its relationship with motor function in Mandarin-speaking children with and without developmental language disorder (DLD). Fifteen children aged 9-12 years with DLD and 15 age- and sex-matched typically developing (TD) children participated in this study. Children's motor function was assessed using the second edition of the Movement Assessment Battery for Children (MABC-2). Their proprioceptive acuity was measured based on the absolute error (i.e., proprioceptive bias) and variable error (i.e., proprioceptive precision) when performing joint position matching tasks. Compared with the TD group, the DLD group exhibited impaired motor function and poorer proprioceptive acuity, as evidenced by the lower scores on the MABC-2 and the higher rates of absolute and variable errors in the joint position matching tasks. A significant association between the proprioceptive bias (absolute error) and the MABC-2 total score was also observed in the combined cohort of children with and without DLD. We conclude that DLD is associated with proprioceptive dysfunction.

Proprioception evaluation and treatment: Hand therapist practice patterns

BACKGROUND

Little is known about how hand therapists assess proprioception and treat deficits in clinical practice and what types of diagnoses they see most often. To our knowledge, no survey has been completed regarding proprioception practice patterns among hand therapists.

PURPOSE

The purpose of this study was to examine current practice patterns related to the treatment and assessment of proprioception deficits by hand therapists in the United States.

STUDY DESIGN

This was a cross-sectional study using a survey instrument.

METHODS

The survey was sent to occupational and physical therapists identified as certified hand therapists or members of the American Society of Hand Therapists. The Checklist for Reporting Results of Internet E-Surveys was used in reporting results.

RESULTS

Members of American Society of Hand Therapists (n=152) responded to the survey. The participants were asked if they provided rehabilitation services to people who have proprioceptive deficits, and 122 (82%) responded yes, and 27 (18%) responded no. Most therapists use a standardized technique for assessing proprioceptive deficits. Hand therapists' mean confidence level in treating proprioception deficits was 7.2 out of 10 compared to the mean confidence level reported evaluating them, which was 6.1 out of 10.

CONCLUSIONS

Most hand therapists evaluate and treat proprioception deficits across a variety of diagnoses. While the frequency and duration of proprioception treatment varies, most hand therapists reported high use of open- and closed-chain exercises and activities along with elastic taping as part of their intervention approach.

Robotic systems for upper-limb rehabilitation in multiple sclerosis: a SWOT analysis and the synergies with virtual and augmented environments

The robotics discipline is exploring precise and versatile solutions for upper-limb rehabilitation in Multiple Sclerosis (MS). People with MS can greatly benefit from robotic systems to help combat the complexities of this disease, which can impair the ability to perform activities of daily living (ADLs). In order to present the potential and the limitations of smart mechatronic devices in the mentioned clinical domain, this review is structured to propose a concise SWOT (Strengths, Weaknesses, Opportunities, and Threats) Analysis of robotic rehabilitation in MS. Through the SWOT Analysis, a method mostly adopted in business management, this paper addresses both internal and external factors that can promote or hinder the adoption of upper-limb rehabilitation robots in MS. Subsequently, it discusses how the synergy with another category of interaction technologies - the systems underlying virtual and augmented environments - may empower Strengths, overcome Weaknesses, expand Opportunities, and handle Threats in rehabilitation robotics for MS. The impactful adaptability of these digital settings (extensively used in rehabilitation for MS, even to approach ADL-like tasks in safe simulated contexts) is the main reason for presenting this approach to face the critical issues of the aforementioned SWOT Analysis. This methodological proposal aims at paving the way for devising further synergistic strategies based on the integration of medical robotic devices with other promising technologies to help upper-limb functional recovery in MS.

The Effectiveness of Goal-Oriented Dual Task Proprioceptive Training in Subacute Stroke: A Retrospective Observational Study

OBJECTIVE

To show the effectiveness of goal-oriented proprioceptive training in subacute stroke for balance, autonomy, and fall risk.

METHODS

Out a total of 35 patients, consistent in age (75.31±8.65 years), type of stroke (ischemic, 3 to 11 weeks before), and motor impairment, 18 patients underwent solely proprioceptive rehabilitation, the other 17 dual task exercises. The study assessed autonomy using Barthel Index, fall risk with Timed Up and Go Test (TUG), balance through Berg Balance Scale (BBS) and Tinetti test.

RESULTS

After two months, significant improvements were recorded in Barthel Index, BBS (p<0.0001), Tinetti test (p<0.0001 in dual task group, p=0.0029 in single task group), and TUG (p=0.0052 in dual task group, p=0.0020 in single task group) in both groups. Comparing the two groups, dual task group showed a significant difference in Tinetti balance assessment (p=0.0052), between the total score of Tinetti test and TUG in single (p=0.0271), and dual task (p=0.0235). Likewise, Tinetti gait test was significantly related to TUG in single (p=0.0536), and dual task (p=0.0466), while Tinetti balance test to Barthel Index (p=0.0394), BBS (p<0.0001), and TUG in single (p=0.0219), and dual task (p=0.0196). Lastly, there is a positive correlation of the use of aids with BBS (p=0.0074), and total score of Tinetti test (p=0.0160).

CONCLUSION

In subacute stroke, goal-oriented proprioceptive training improved balance, but only partially autonomy. Furthermore, the use of aids after dual-task exercises improved recovery of balance, but did not reduced falls.

Efficacy of scapulothoracic exercises on proprioception and postural stability in cranio-cervico-mandibular malalignment: A randomized, double-blind, controlled trial

BACKGROUND

Cranio-cervico-mandibular (CCM) malalignment is associated with forward head posture (FHP) and temporomandibular joint (TMJ) disorders and affects masticatory muscles.

OBJECTIVE

This randomized, double-blind controlled trial aimed to compare the efficacy of scapula-thoracic (ST) exercises on temporomandibular and cervical joint position sense and postural stability in individuals with CCM malalignment.

METHODS

Fourty-nine participants with CCM malalignment were randomly assigned to the ST exercise group (STEG, n= 24) or the control group (CG, n= 25). STEG included progressive strengthening, proprioceptive, and stabilization exercises. All participants were assessed before treatment, at the end of the 8th week treatment period and at the 12th week post-treatment follow-up. Cranio-vertebral angle measurement, Fonseca's Questionnaire, Helkimo Clinical Dysfunction Index, TMJ position test, cervical joint position error test and postural stability assessment were used.

RESULTS

The TMJ and cervical joint position sense, total sway degree, area gap percentage, sway velocity and antero-posterior body sway results showed significant improvement in the STEG compared to the CG (p< 0.05), however medio-lateral body sway did not differ between groups (p> 0.05).

CONCLUSIONS

Postural stability, TMJ and cervical joint position sense appear to be affected in individuals with CCM malalignment. Our results showed that an exercise program including ST stabilization, proprioception and strengthening of the scapular muscles may be effective in the management of CCM malalignment and will allow clinicians to plan holistic treatment.

Limitations in utilization and prioritization of standardized somatosensory assessments after stroke: A cross-sectional survey of neurorehabilitation clinicians

BACKGROUND AND PURPOSE

Somatosensory impairments are common after stroke, but receive limited evaluation and intervention during neurorehabilitation, despite negatively impacting functional movement and recovery.

OBJECTIVES

Our objective was to understand the scope of somatosensory assessments used by clinicians in stroke rehabilitation, and barriers to increasing use in clinical practice.

METHODS

An electronic survey was distributed to clinicians (physical therapists, occupational therapists, physicians, and nurses) who assessed at least one individual with stroke in the past 6 months. The survey included questions on evaluation procedures, type, and use of somatosensory assessments, as well as barriers and facilitators in clinical practice.

RESULTS

Clinicians (N = 431) indicated greater familiarity with non-standardized assessments, and greater utilization compared to standardized assessments (p < 0.0001). Components of tactile sensation were the most commonly assessed modality of somatosensation (25%), while proprioception was rarely assessed (1%). Overall, assessments of motor function were prioritized over assessments of somatosensory function (p < 0.0001).

DISCUSSION

Respondents reported assessing somatosensation less frequently than motor function and demonstrated a reliance on rapid and coarse non-standardized assessments that ineffectively capture multi-modal somatosensory impairments, particularly for proprioceptive deficits common post-stroke. In general, clinicians were not familiar with standardized somatosensory assessments, and this knowledge gap likely contributes to lack of translation of these assessments into practice.

CONCLUSIONS

Clinicians utilize somatosensory assessments that inadequately capture the multi-modal nature of somatosensory impairments in stroke survivors. Addressing barriers to clinical translation has the potential to increase utilization of standardized assessments to improve the characterization of somatosensory deficits that inform clinical decision-making toward enhancing stroke rehabilitation outcomes.

Acute effects of an isometric neck warm-up programme on neck performance characteristics and ultrasound-based morphology

OBJECTIVE

Athletic performance can be enhanced immediately after an isometric warm-up, a phenomenon termed post-activation performance enhancement (PAPE). While isometric warm-ups can improve lower extremity sprint and jump performance, neck-specific isometric warm-ups need development and validation for mild traumatic brain disorders and neck pain. This study examined acute effects of isometric warm-ups on neck performance and morphology.

METHODS

Arm 1: Twenty-six adults (13 M:13F) completed neck performance testing before and after a 10-minute neck isometric warm-up or stationary bike (sham) between two visits. Testing included visual-motor reaction time, peak force, rate of force development, force steadiness, and force replication/proprioception measured by a 6-axis load cell. An inclinometer assessed range-of-motion. Paired t-tests and two-way ANOVA examined effects of neck/bike warm-up and interaction effects, respectively. Arm 2: 24 adults (11 M:13F) completed ultrasound scans of cervical muscles: before 20-minute rest (sham), and before/after a 5-min neck isometric warm-up. Longus colli cross-sectional area and sternocleidomastoid/upper trapezius thickness and stiffness, and cervical extensors thickness was assessed. One-way ANOVA compared morphological values at sham, before, and after warm-up. Significance was set at p < 0.05.

RESULTS

Isometric neck warm-up increased rate of force development in flexion (p = 0.022), extension (p = 0.001-0.003), right lateral flexion (p = 0.004-0.032), left lateral flexion (p = 0.005-0.014), while peak force improved only in left lateral flexion (p = 0.032). Lateral flexion range-of-motion increased after neck warm-up (p = 0.003-0.026). Similarly, longus colli cross-sectional area (p = 0.016) and sternocleidomastoid thickness (p = 0.004) increased.

CONCLUSIONS

Increased neck performance characteristics and morphology are likely due to PAPE effects of isometric neck warm-up. For coaches and athletes, simple isometric contractions could be added to existing warm-ups to reduce prevalence, incidence, and severity of mild traumatic brain injuries and neck pain.

A Physically Active Lifestyle Can Protect against Age-Related Decline in Ankle Proprioception

This study examined whether physically active middle-aged (50-64 years) and older adults (65-80 years) demonstrate age-related ankle proprioceptive decline relative to younger counterparts. Empirical data indicate that ankle proprioception declines with aging and such sensory decline negatively affects balance. Using a passive motion apparatus, we employed a psychophysical forced-choice paradigm in which the ankle was passively plantarflexed to a reference position (15° or 25°) and a comparison position that was always smaller than the reference. Subsequently, participants indicated which position was more plantarflexed. As outcome measures of ankle position sense acuity, a just-noticeable-difference (JND) threshold and the uncertainty area (UA) were derived from the psychometric stimulus-response difference function for each participant. The JND threshold is a measure of proprioceptive bias and UA constitutes a measure of precision. The main results are: First, at the 15° reference, most middle-aged (74%) and older adults (71%) had thresholds within the range of the young adults. The respective median JND threshold of young adults was statistically lower when compared to both older groups. Second, no differences between age groups were observed at the 25° reference. Third, no age-related differences were found for UA at either reference. These data indicate that physically active aging adults may be spared from age-related decline in ankle position sense and that age-related differences emerge for small ankle displacements. The findings underscore the importance of remaining active during aging.

Effects of proprioception and core stability training on gait parameters of deaf adolescents: a randomized controlled trial

The current study aimed to explore the effects of proprioception versus core stability training over 8 weeks on the gait parameters of deaf adolescents. A total of 20 deaf adolescents were randomized into two groups: one group receiving proprioception training (PT, n = 10), another group receiving core stability training (CST, n = 10), and eleven typically developing adolescents assigned into the control group (CON; n = 11). Gait was recorded by two digital cameras; then, using the Kinovea software, the parameters of gait included: gait velocity, cadence, stride length, stride time, stance time, and swing time were calculated in terms of percentages of the walking cycle. After 8 weeks of PT, no significant differences were observed for all gait parameters between PT and control groups (p > 0.05). Also, after 8 weeks of CST, no significant differences were observed in gait velocity and cadence between the CST and control groups (p > 0.05). However, after 8 weeks of CST, stride length (p = 0.02) was higher in the control group; Stride time (p = 0.03), stance time (p = 0.04) and swing time (p = 0.04) were higher in the CST group. Moreover, after 8 weeks of PT, values showed significant improvements in all gait parameters (p = 0.001). Also, after 8 weeks of CST, values showed significant improvements in gait velocity and cadence (p = 0.001), but no significant differences were observed in other gait parameters (p > 0.05). The findings of this study indicated that PT improved all gait parameters, whereas CST improved gait velocity and cadence. The results of the present study also demonstrated that PT had a greater effect on gait parameters of deaf adolescents compared with CST. It seems that PT induces more training effects than CTS for enhancing gait parameters of deaf adolescents.Trial registration: Clinical trial registry number: IRCT20170312033029N2. URL: https://en.irct.ir/trial/25584 .

The Evolution of Hand Proprioceptive and Motor Impairments in the Sub-Acute Phase After Stroke

BACKGROUND

Hand proprioception is essential for fine movements and therefore many activities of daily living. Although frequently impaired after stroke, it is unclear how hand proprioception evolves in the sub-acute phase and whether it follows a similar pattern of changes as motor impairments.

OBJECTIVE

This work investigates whether there is a corresponding pattern of changes over time in hand proprioception and motor function as comprehensively quantified by a combination of robotic, clinical, and neurophysiological assessments.

METHODS

Finger proprioception (position sense) and motor function (force, velocity, range of motion) were evaluated using robotic assessments at baseline (<3 months after stroke) and up to 4 weeks later (discharge). Clinical assessments (among others, Box & Block Test [BBT]) as well as Somatosensory/Motor Evoked Potentials (SSEP/MEP) were additionally performed.

RESULTS

Complete datasets from 45 participants post-stroke were obtained. For 42% of all study participants proprioception and motor function had a dissociated pattern of changes (only 1 function considerably improved). This dissociation was either due to the absence of a measurable impairment in 1 modality at baseline, or due to a severe lesion of central somatosensory or motor tracts (absent SSEP/MEP). Better baseline BBT correlated with proprioceptive gains, while proprioceptive impairment at baseline did not correlate with change in BBT.

CONCLUSIONS

Proprioception and motor function frequently followed a dissociated pattern of changes in sub-acute stroke. This highlights the importance of monitoring both functions, which could help to further personalize therapies.

Motion sense sensitivity of the ankle is abnormal and correlated with motor performance in children with and without a probable developmental coordination disorder

This study systematically examined ankle motion sense sensitivity and its relation to motor functions in children with and without a probable developmental coordination disorder (pDCD). Seventy-two children aged 10-11 years were recruited, including thirty-six children with pDCD and 36 age- and sex-matched typically developing (TD) children. Children placed their dominant foot on a passive ankle motion apparatus that induced plantar flexion of the ankle under nine constant velocities ranging between 0.15 and 1.35°/s. The adjusted movement detection time (ADT) to passive ankle motion was obtained to measure ankle motion sense sensitivity. The results showed that, in comparison to that in the TD group, ankle ADT was significantly increased by 22-59% for the range of velocities in the pDCD group. A correlation analysis showed that mean ADTs were significantly correlated with the manual dexterity (r = -0.33, p = 0.005) and balance (r = -0.24, p = 0.046) scores on the Movement Assessment Battery for Children (MABC-2) in the combined group. Similar correlations were found between the ADTs and the manual dexterity (r = -0.37, p = 0.028) and total motor (r = -0.34, p = 0.047) scores in the TD group. This study documents that ankle motion sense sensitivity to passive foot motion is reduced and is likely to contribute to poor motor performance in children with and without pDCD.

Use of variable online visual feedback to optimize sensorimotor coding and learning of a motor sequence

The present study characterized the impact of reliable and/or unreliable online visual feedback and their order of presentation on the coding and learning of a motor sequence. Participants practiced a 12-element motor sequence 200 times. During this acquisition phase, two groups received a single type (i.e., either reliable or unreliable) of online visual feedback, two other groups encountered both types of feedback: either reliable first then unreliable, or unreliable first then reliable. Delayed retention tests and intermanual transfer tests (visuospatial and motor) were administered 24 hours later. Results showed that varying the reliability of online visual information during the acquisition phase allowed participants to use different task coding modalities without damaging their long-term sequence learning. Moreover, starting with reliable visual feedback, replaced halfway through with unreliable feedback promoted motor coding, which is seldom observed. This optimization of motor coding opens up interesting perspectives, as it is known to promote better learning of motor sequences.

A Systematic Review of the Learning Dynamics of Proprioception Training: Specificity, Acquisition, Retention, and Transfer

OBJECTIVE

We aimed to identify key aspects of the learning dynamics of proprioception training including: 1) specificity to the training type, 2) acquisition of proprioceptive skills, 3) retention of learning effects, and 4) transfer to different proprioceptive skills.

METHODS

We performed a systematic literature search using the database (MEDLINE, EMBASE, Cochrane Library, and PEDro). The inclusion criteria required adult participants who underwent any training program that could enhance proprioceptive function, and at least 1 quantitative assessment of proprioception before and after the intervention. We analyzed within-group changes to quantify the effectiveness of an intervention.

RESULTS

In total, 106 studies with 343 participant-outcome groups were included. Proprioception-specific training resulted in large effect sizes with a mean improvement of 23.4 to 42.6%, nonspecific training resulted in medium effect sizes with 12.3 to 22% improvement, and no training resulted in small effect sizes with 5.0 to 8.9% improvement. Single-session training exhibited significant proprioceptive improvement immediately (10 studies). For training interventions with a midway evaluation (4 studies), trained groups improved by approximately 70% of their final value at the midway point. Proprioceptive improvements were largely maintained at a delayed follow-up of at least 1 week (12 studies). Finally, improvements in 1 assessment were significantly correlated with improvements in another assessment (10 studies).

CONCLUSIONS

Proprioceptive learning appears to exhibit several features similar to motor learning, including specificity to the training type, 2 time constant learning curves, good retention, and improvements that are correlated between different assessments, suggesting a possible, common mechanism for the transfer of training.

Impedance Control of a 2-DOF Spherical 5-Bar Exoskeleton for Physical Human-Robot Interaction During Rehabilitation and Assessment

This paper presents a novel impedance controller for THINGER (THumb INdividuating Grasp Exercise Robot), a 2-degree-of-freedom (DOF) spherical 5-bar exoskeleton designed to augment FINGER (Finger INdividuating Grasp Exercise Robot). Many rehabilitation and assessment tasks, for which THINGER is designed, are improved by rendering near-zero impedance during physical human-robot interaction (pHRI). To achieve this goal, the presented impedance controller includes several novel features. First, a reference trajectory is omitted, allowing free movements. Second, force-feedback gains are reduced near actuator limits and a saturation function limits the maximum commanded force; both allow more responsive (higher) force-feedback gains within the workspace and mitigate transient oscillations caused by external disturbances. Finally, manipulability-based directional force-feedback gains help improve rendered impedance isotropy. Validation experiments included free exploration of the workspace, following a prescribed circular thumb motion, and intentional exposure to external disturbances. The experimental results show that the presented impedance controller significantly reduces impedance to subject-initiated motion and accurately renders the desired isotropic low-impedance environment.

A Cross-Sectional Study Investigating Lumbar Proprioception Impairments in Individuals with Type 2 Diabetes Mellitus: Correlations with Glycated Hemoglobin Levels

Impaired proprioception is a recognized complication in individuals with type 2 diabetes mellitus (T2DM), contributing to balance deficits and increased risk of falls. However, limited research has focused on lumbar proprioception in this population. This study aimed to investigate lumbar proprioception in individuals with T2DM, as well as healthy individuals. Additionally, this study aimed to examine the correlation between lumbar proprioception and glycated hemoglobin (HbA1c) levels, which is a marker of long-term glycemic control in T2DM. A cross-sectional study was conducted, comparing lumbar joint reposition errors (JRE) between a T2DM group (n = 85) and a healthy group (n = 85). Lumbar JRE was assessed in flexion, extension, lateral bending left, and lateral bending right using a dual inclinometer device. HbA1c levels were measured as an indicator of glycemic control. Significant differences in lumbar JRE were found between the T2DM and healthy groups, with individuals with T2DM exhibiting larger JRE values, indicating impaired lumbar proprioception (p < 0.001). The correlation analysis revealed significant positive associations between HbA1c levels and lumbar JRE. Higher HbA1c levels were correlated with greater joint JRE in flexion (r = 0.49, p < 0.001), extension (r = 0.51, p < 0.001), left lateral bending (r = 0.45, p < 0.001), and right lateral bending (r = 0.48, p < 0.001) in the T2DM group. This study provides evidence of impaired lumbar proprioception in individuals with T2DM, as evidenced by larger lumbar JRE compared to the healthy group.

Effectiveness and safety of subthreshold vibration over suprathreshold vibration in treatment of muscle fatigue in elderly people

Muscle fatigue is common in many populations, particularly elderlies. Aging increases the incidence of muscle fatigue and delays its recovery. There is a huge debate about the current treatments for muscle fatigue, particularly in elderlies. Recently, it has been discovered that mechanoreceptors have an important role as a sensory system in sensing muscle fatigue which could enhance the body's response to muscle fatigue. The function of mechanoreceptors could be enhanced by applying either suprathreshold or subthreshold vibration. Although suprathreshold vibration improves muscle fatigue, it can cause desensitization of cutaneous receptors, discomfort, and paresthesia, which are barriers to clinical use. Subthreshold vibration has been approved as a safe and effective method of training for mechanoreceptors; however, its use and effectiveness in muscle fatigue have never been tested or explained. Possible physiological effects of subthreshold vibration in the treatment of muscle fatigue include: (1) Enhancing the function of mechanoreceptors themselves; (2) Increasing the firing rate and function of alpha motor neurons; (3) Increasing blood flow to fatigued muscles; (4) Decreasing the rate of muscle cell death in elderlies (sarcopenia); and (5) Driving motor commands and allow better performance of muscles to decrease fatigue incidence. In conclusion, the use of subthreshold vibration could be a safe and effective treatment for muscle fatigue in elderlies. It could enhance recovery from muscle fatigue. Finally, Subthreshold Vibration is safe and effective in treating muscle fatigue in comparison to suprathreshold vibration.

Design and Preliminary Evaluation of a Robot-assisted Assessment-driven Finger Proprioception Therapy

Neurological injuries such as stroke often lead to motor and somatosensory impairments of the hand. Deficits in somatosensation, especially proprioception, result in difficulties performing activities of daily living involving fine motor tasks. However, it is challenging to accurately detect those impairments due to the limitations of clinical assessments. Hence therapies rarely focus on proprioception specifically, while such training could promote functional benefits. In this work we propose and preliminarily evaluate a robot-assisted, assessment-driven therapy of finger proprioception. We designed and implemented two therapeutic exercises, one targeting passive and the other active position sense. The difficulty level of the therapy exercises was adapted to each patient's proprioceptive impairment. We evaluated the exercises and their usability with 7 stroke participants and 8 clinicians in a 45-minutes protocol. We found that the exercises were feasible for stroke participants, as 5 individuals progressed in difficulty levels over multiple exercise repetitions, indicating adequacy of the adaptation algorithm. Moreover, usability was rated mostly as satisfactory by the patients (System Usability Scale = 73), and they also found the exercises interesting. Clinicians rated the exercises as difficult but clinically meaningful. Overall, these promising preliminary results pave the way for further development and validation of the proposed therapy approach.