Degradation of cervical joint position sense following muscular fatigue in humans

The effect of proprioceptive neuromuscular facilitation on individuals with text neck syndrome: A randomized controlled study

BACKGROUND

Text neck syndrome is an overuse condition that has become a global problem for all ages who use smartphones. Although therapeutic approaches are used to manage text neck syndrome, relatively little evidence exists on efficacy. This study aimed to investigate the effects of proprioceptive neuromuscular facilitation (PNF) techniques on individuals with text neck syndrome.

METHODS

Thirty-eight participants with text neck syndrome were randomly allocated to either the experimental or control group. Both groups performed the program including cervical range of motion, strengthening, and posture correction exercises for 6 weeks, 3 days a week, once a day for 10 repetitions. In the experimental group were included in a PNF program 3 days a week for 6 weeks. In the program, contract-relax and replication techniques were used. Pain intensity, cervical range of motion, cervical muscles' endurance, posture, and disability were assessed. Outcome measures were assessed at baseline and after 6 weeks.

RESULTS

Pain intensity, neck muscle endurance tests, posture, and disability scores significantly improved in both groups (P < .05). The cervical range of motion values in all directions were significantly increased only in the experimental group (P < .05). The improvements in pain intensity, neck muscle endurance tests, posture, and disability scores were greater in the experimental group compared with the control group (P < .05).

CONCLUSION

PNF could be used effectively to reduce neck pain and disability level and enhance cervical range of motion, cervical muscles' endurance, and posture in individuals with text neck syndrome.

Typical Cockpit Ergonomics Influence on Cervical Motor Control in Healthy Young Male Adults

INTRODUCTION: Neck pain and injury are common problems in military high-performance aircraft and helicopter aircrews. A contributing factor may be the reclined sitting position in cockpits. This study aimed to determine the effect of typical cockpit ergonomics on cervical proprioception, assessed by using the cervical joint position error (cJPE).METHODS: A total of 49 healthy male military employees (mean age 19.9 ± 2.2 yr) were examined. Measurements of the cJPE were obtained in the flexion, extension, and rotation directions in an upright and in a 30°-reclined sitting position. Each condition comprised three trials, with an additional 3-kg head load to mimic real world working conditions.RESULTS: A smaller cJPE was noted in the 30°-reclined sitting position (mean cJPE = 3.9 cm) than in the upright sitting position (mean cJPE = 4.6 cm) in the flexion direction. The cJPE decreased significantly in all movement directions across the three trials; for example, in the flexion direction in the 30°-reclined sitting position: Trial 1/2/3 mean cJPE = 5.0/3.8/3.1 cm.CONCLUSION: It seems that a reclined seating position has a positive influence on cJPE. However, the result is weak. In both sitting positions and all three directions, the first tests of the cJPE showed the highest values. Already after one or two further measurement runs, a significantly reduced cJPE was observed. This rapid improvement might indicate that an exercise similar to the cJPE test may improve the pilots' cervical proprioception and possibly reduce the risk of injury or pain.Heggli U, Swanenburg J, Hofstetter L, Häusler M, Schweinhardt P, Bron D. Typical cockpit ergonomics influence on cervical motor control in healthy young male adults. Aerosp Med Hum Perform. 2023; 94(3):107-112.

Cervical Joint Position Sense and Its Correlations with Postural Stability in Subjects with Fibromyalgia Syndrome

Cervical joint position sense (JPS) and postural stability are vital to maintaining balance and preventing falls in fibromyalgia syndrome (FMS). Impaired cervical JPS may influence postural stability, and understanding the relationship between them can aid in formulating treatment strategies in individuals with FMS. This study aims to (1) assess cervical JPS and postural stability between FMS and control group and (2) determine the correlation between cervical JPS and postural stability in the FMS group. This cross-sectional study recruited 92 FMS patients (mean age: 51.52 ± 7.7 yrs.) and 92 healthy controls (mean age: 49.36 ± 6.9 yrs.). A cervical range of motion (CROM) unit was utilized to assess cervical JPS. The postural stability was assessed using an IsoFree force platform, and anterior-posterior (A/P) and medial-lateral (M/L) directions of sway and ellipse area were measured. Cervical JPS and postural stability tests were assessed and compared between FMS and control groups. Cervical JPS was significantly impaired in FMS compared to the control group (p < 0.001). The JPS errors in FMS group were larger in flexion (FMS = 5.5°, control = 2.4°), extension (FMS = 6.4°, control = 3.0°), and rotation in left (FMS = 5.4°, control = 2.2°) and right directions (FMS = 5.1°, control = 2.8°). FMS individuals demonstrated statistically significant impaired postural stability compared to control in both the dominant and non-dominant legs tested (p < 0.001). The cervical JPS test showed moderate to strong positive correlations with postural stability variables. Statistically significant correlations were observed in all the JPS directions tested with all the postural stability variables (A/P and M/L sway and ellipse area). The correlation coefficients ranged between r = 0.37 (moderate) to 0.75 (strong). Cervical JPS and postural stability are impaired in FMS individuals. A moderate to strong relationship existed between JPS and postural stability. Individuals with FMS who had a greater magnitude of cervical JPS errors exhibited more severe postural control deficits. Therefore, cervical JPS and postural stability tests should be incorporated into routine clinical practice when assessing or formulating treatment strategies for patients with FMS.

The effects of experimentally-induced fatigue on gait parameters during obstacle crossing: A systematic review

Striking an obstacle while walking can be dangerous, reflecting the higher risks of losing one's balance, tripping and falling. Particular situations during which internal resources are limited, such as in a fatigued state, may impair performance when crossing obstacles, enhancing the risks of falls or accidents. Our goal was thus to review the effects of experimentally-induced fatigue (EIF) on gait parameters during obstacle crossing by healthy individuals. We systematically searched PubMed and Web of Science databases using 'fatigue', 'obstacle crossing' and their equivalent terms to extract data from studies investigating this domain. Nine studies were found. First, EIF-related effects on kinetics, EMG and obstacle contacts have been poorly studied. Second, consistent and inconsistent results were found in the kinematic outcomes after EIF. Consistent results included reductions in stride duration and increased step width. Inconsistent results included gait velocity (no-effect vs increased), leading and trailing-foot vertical clearance (reduced vs increased) and horizontal distance from foot to the obstacle before obstacle avoidance (no-effect vs increased). These findings should be interpreted cautiously, however, due to the heterogeneity of the obstacle crossing and EIF protocols.

The effect of walking and stationary work on the acute back pain, muscle activation, posture and postural control of older women

Back pain is associated with activity such as walking or assembly line work that involves upper-body movement. However, no single study has explored the effect of these tasks on back pain, spinal angles and balance in an older adult female population. This study investigated changes in back pain, postural sway, upper-, lower- and full-spine angle and EMG activation of trunk muscles following 30 minutes of walking and a modified quiet standing task. Fourteen older adult females (62 ± 11yrs) with low to moderate chronic back pain were recruited as participants. Findings demonstrated that following these activities, increased acute back pain and upper-spine flexion occur although acute back pain was not clinically significant; postural control and muscle activation remained unchanged. This suggests that walking and modified quiet standing can lead to subtle acute back pain in older females that could be due to an increased upper spinal flexion rather than muscle fatigue. Practitioner summary: Back pain and postural problems are common in older adults. Older adult female participants experienced increased back pain and greater upper-spine flexion following 30-minute walking and standing with trunk rotation, but the practical importance was less clear. However, balance was unaffected, suggesting no increase in fall risk. Abbreviations: CBP: chronic back pain; MQS: modified quiet standing; QS: quiet standing; RPE: rating of perceived exertion; TD: trapezius descendens; TT: trapezius transversalis; TA: trapezius ascendens; ESL: erector spinae longissimus; C7: seventh cervical vertebrae; T7: seventh thoracic vertebrae; T10: tenth thoracic vertebrae; T12: twelfth thoracic vertebrae; L2: second lumbar vertebrae; S2: second sacral vertebrae; AP: anterior-posterior; ML: medial-lateral; SWAYtot: total postural sway; M: mean.

Contribution of Cervical Proprioception, Vision, and Vestibular Feedback on Reducing Dynamic Head–Trunk Orientation Error in the Yaw Direction

The contribution of cervical proprioception, vision, and vestibular feedback to the dynamic head–trunk orientation error in the yaw direction was investigated to further the understanding over the mechanism of coordination among different sensory modalities for dynamic head–trunk orientation. To test the contribution of each sensory modality, individually and together, to dynamic head–trunk orientation, 10 healthy human subjects participated in the extended cervical joint position error test, measuring the ability of repositioning the head back to the reference orientation after 45° yaw rotation of head or trunk. The error between initial and returned angles was measured. The test was repeated under eight different conditions of sensory feedback, with or without each of three sensory modalities. Each subject completed 64 trials (8 per condition) in a random order for fair comparison. No change was found in bias when one of the three modalities was missing, while variance was largest at the lack of dynamic cervical proprioception. When two of the three modalities were missing (i.e., one of the three modalities was present), both bias and variance were minimum at the presence of cervical proprioception. Additionally, both visual and vestibular feedback was redundant (i.e., no further improvement in both bias and variance), if the other one (visual or vestibular feedback) was present with dynamic cervical proprioception. In sum, the experimental results suggest that dynamic cervical proprioception is the most significant sensory modality for reducing the dynamic head–trunk orientation error in the yaw direction.

Clinical Changes in Cervical Neuromuscular Control Following Subconcussive Impacts

CONTEXT

Increased injury rates following concussive injury have been attributed to decreased neuromuscular coordination frequently documented following a concussion. However, altered integration between the vestibular system and oculomotor pathways following impacts at subconcussive thresholds implicate all sports-related impacts not just those at a concussive threshold in future musculoskeletal injury. While, several studies have explored the utility of vestibular and oculomotor clinical testing to detect altered neuromuscular control and then correlated those alterations to future injury risk, no research has explored the use of cervical clinical tests in the same capacity.

OUTCOME MEASURES

Cervical joint position error test, Neck Disability Index and head acceleration.

INTERVENTIONS

Soccer headers, fatigue protocol, soccer headers + fatigue.

OBJECTIVE

To explore the clinical utility of a novel clinical approach to measuring changes in cervical neuromuscular control following subconcussive impacts in a controlled lab environment.

PARTICIPANTS

40 current female colligate club soccer athletes were recruited. Inclusion criteria included between the age of 18 and 25 and a minimum of 4-year soccer heading experience.

SETTING

Laboratory.  Design: A repeated-measures design with 4 groups was utilized to test the hypothesis.

RESULTS

A 65%, 54%, and 49% increased error was observed following the soccer heading, fatigue only, and soccer heading + fatigue interventions, respectively. Meanwhile, the controls saw a 6% decrease in neck position error. Concussion: While, cervical joint position error testing was sensitive to decreased neuromuscular coordination following soccer heading, it was not specific enough to rule out an exercise effect in the absence of subconcussive impacts. Further research is warranted to explore the clinical utility and specificity of cervical joint position error testing to measured alterations in supraspinal processing following subconcussive impacts, and how these alterations may lead to decreased coordination and movement of the body during sports-related task.

Cervical proprioceptive impairment in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) involving the cervical spine can lead to various neurologic defects and impairment of proprioception is just one of them. The aim of this study was the assessment of cervical proprioception and its relation with radiographic, clinical, and functional characteristics of patients with RA. One hundred and six rheumatoid arthritis patients who diagnosed according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria and age, gender, educational status matched one hundred and six healthy volunteers were enrolled in this study. Cervical joint position error test (CJPET) was applied to healthy volunteers and RA patients for cervical proprioception assessment. Fatigue, depression, balance, quality of life and balance scales were administered to all patients. Cervical radiography was used to assess cervical subluxations. Regression analysis was used for grading the factors which had relations with cervical proprioception. Mean age of patients and healthy volunteers was 51 ± 11.1 and 48.9 ± 9.2, respectively. Scores of CJPET were statistically significantly higher in RA group than healthy volunteers (p = 0.001). CJPET scores were negatively correlated with Berg balance scale findings in right rotation, left rotation, flexion and extension (rho = - 0.421,- 0.473,- 0.448,- 0.515). There was weak or not significant correlation between the scores of CJPET and fatigue, depression, and quality of life scales. Scores of CJPET in patients with atlantoaxial subluxations (AAS) were statistically significantly higher than those without AAS (p < 0.05). Regression analysis results showed that the AAS was related to impaired cervical proprioception on right and left rotations. There was no correlation between CJPET scores and functional parameters. Cervical proprioception impaired in RA patients. This impairment was related to the existence of AAS and balance problems.

Disturbance of neck proprioception and feed-forward motor control following static neck flexion in healthy young adults

The highly complex proprioceptive system provides neuromuscular control of the mobile cervical spine. Static neck flexion can induce the elongation of posterior tissues and altered afferent input from the mechanoreceptors. The purpose of this study was to examine the effect of prolonged static neck flexion on neck proprioception and anticipatory postural adjustments. Thirty-eight healthy participants (20 females and 18 males) between the ages of 20-35 years with no history of neck, low back, and shoulder pain enrolled in this study. Neck proprioception and anticipatory muscle activity were tested before and after 10-min static neck flexion. For assessment of neck proprioception, each participant was asked to perform 10 trials of the cervicocephalic relocation test to the neutral head position after active neck rotation to the left and right sides. Anticipatory postural adjustments were evaluated during a rapid arm flexion test. Following the flexion, the absolute and variable errors in head repositioning significantly increased (p < 0.05). The results also showed that there was a significant delay in the onset of myoelectric activity of the cervical erector spinae muscles after flexion (p = 0.001). The results of this study suggested that a 10-min static flexion can lead to changes in the neck proprioception and feed-forward control due to mechanical and neuromuscular changes in the viscoelastic cervical spine structures. These changes in sensory-motor control may be a risk factor for neck pain and injury.

Relationship Between Proprioception and Endurance Functionality of the Cervical Flexor Muscles in Chronic Neck Pain and Asymptomatic Participants

OBJECTIVE

The purpose of this study was to compare the relationship between flexion endurance capacity and joint position error in participants with or without chronic neck pain (CNP).

METHODS

Sixty-one CNP and 60 asymptomatic volunteers participated in this cross-sectional, case-control, and correlational analysis study. The measured variables included absolute and constant joint repositioning errors in the sagittal and horizontal directions, clinical flexor endurance test score, pain intensity, and neck disability index.

RESULTS

The groups did not statistically differ in flexion endurance (P > .05). The CNP group had a smaller absolute error on the right (P < .01) and left (P = .01) rotation and an overshooting error pattern in the flexion direction (P < .05). But the asymptomatic group did not exhibit any over-/undershooting pattern tendency (P > .05). Although flexion endurance was not correlated with any of the joint repositioning error components in either group, pain and disability scores were significantly correlated with left rotation absolute error (r = -0.34 and ρ = -0.37, respectively).

CONCLUSION

The clinical cervical flexor endurance test, ignoring the relative contribution of the deep and superficial groups of muscles, may not efficiently characterize CNP patients.

Influence of chronic neck pain on cervical joint position error (JPE): Comparison between young and elderly subjects

BACKGROUND

Evaluation of cervical joint position sense in subjects with chronic neck pain has gained importance in recent times. Different authors have established increased joint position error (JPE) in subjects with acute neck pain. However, there is a paucity of studies to establish the influence of chronic neck pain on cervical JPE.

OBJECTIVE

The objective of the study was to understand the influence of chronic neck pain on cervical JPE, and to examine the differences in cervical JPE between young and elderly subjects with chronic neck pain.

METHODS

Forty-two chronic neck pain patients (mean age 47.4) were compared for cervical JPE with 42 age-matched healthy subjects (mean age 47.8), using a digital inclinometer. The cervical JPE were measured in flexion, extension, and rotation in right and left movement directions.

RESULTS

The comparison of JPE showed significantly larger errors in subjects with chronic neck pain when compared to healthy subjects (p< 0.001). The errors were larger in all of the movement directions tested. Comparison between young and older subjects with chronic neck pain revealed no significant differences (P> 0.05) in cervical JPE.

CONCLUSIONS

Cervical joint position sense is impaired in subjects with chronic neck pain.

A prospective investigation of changes in the sensorimotor system following sports concussion. An exploratory study

BACKGROUND

Sports concussion is a risk for players involved in high impact, collision sports. Post-concussion, the majority of symptoms subside within 7-10 days, but can persist in 10-20% of athletes. Understanding the effects of sports concussion on sensorimotor systems could inform physiotherapy treatment.

OBJECTIVE

To explore changes in sensorimotor function in the acute phase following sports concussion.

DESIGN

Prospective cohort study.

METHODS

Fifty-four players from elite rugby union and league teams were assessed at the start of the playing season. Players who sustained a concussion were assessed three to five days later. Measures included assessments of balance (sway velocity), vestibular system function (vestibular ocular reflex gain; right-left asymmetry), cervical proprioception (joint position error) and trunk muscle size and function.

RESULTS

During the playing season, 14 post-concussion assessments were performed within 3-5 days of injury. Significantly decreased sway velocity and increased size/contraction of trunk muscles, were identified. Whilst not significant overall, large inter-individual variation of test results for cervical proprioception and the vestibular system was observed.

LIMITATIONS

The number of players who sustained a concussion was not large, but numbers were comparable with other studies in this field. There was missing baseline data for vestibular and cervical proprioception testing for some players.

CONCLUSIONS

Preliminary findings post-concussion suggest an altered balance strategy and trunk muscle control with splinting/over-holding requiring consideration as part of the development of appropriate physiotherapy management strategies.

Cervical spine reposition errors after cervical flexion and extension

BACKGROUND

Upright head and neck position has been frequently applied as baseline for diagnosis of neck problems. However, the variance of the position after cervical motions has never been demonstrated. Thus, it is unclear if the baseline position varies evenly across the cervical joints. The purpose was to assess reposition errors of upright cervical spine.

METHODS

Cervical reposition errors were measured in twenty healthy subjects (6 females) using video-fluoroscopy. Two flexion movements were performed with a 20 s interval, the same was repeated for extension, with an interval of 5 min between flexion and extension movements. Cervical joint positions were assessed with anatomical landmarks and external markers in a Matlab program. Reposition errors were extracted in degrees (initial position minus reposition) as constant errors (CEs) and absolute errors (AEs).

RESULTS

Twelve of twenty-eight CEs (7 joints times 4 repositions) exceeded the minimal detectable change (MDC), while all AEs exceeded the MDC. Averaged AEs across the cervical joints were larger after 5 min' intervals compared to 20 s intervals (p < 0.05).

CONCLUSIONS

This is the first study to demonstrate single joint reposition errors of the cervical spine. The cervical spine returns to the upright positions with a 2° average absolute difference after cervical flexion and extension movements in healthy adults.

Association of age on cervical joint position error

This study quantitatively assesses the association between age and cervical joint position error (JPE) and compares JPE between young and older asymptomatic subjects. Subjects (n = 230) ranging in age from 17 to 70 years volunteered to participate in the study. Cervical JPE was measured for all subjects with the active movement angle reproduction test in degrees using a digital inclinometer; testing was done in all cervical movement directions (flexion, extension, side-bending right and left, rotation right and left). Subjects were divided into two groups: young (n = 169, mean age: 32.4 years; range 17–49 years) and older (n = 61, mean age: 61.9 years; range 50–70 years) and JPE was compared. Pearson’s product-moment correlation coefficients were significant and positive for the association of age on cervical JPE in flexion (r = 0.71), extension (r = 0.81), side-bending right (r = 0.77), side-bending left (r = 0.84), rotation right (r = 0.84), and rotation left (r = 0.84). JPE was significantly larger (for all movement directions) in the older subject group (P < 0.001). Advancing age was significantly associated with the increasing cervical JPE and older subjects showed greater errors when compared to younger subjects.

Accuracy of Different Modalities to Record Natural Head Position in 3 Dimensions: A Systematic Review

PURPOSE

Three-dimensional (3D) images are taken with positioning devices to ensure a patient's stability, which, however, place the patient's head into a random orientation. Reorientation of images to the natural head position (NHP) is necessary for appropriate assessment of dentofacial deformities before any surgical planning. The aim of this study was to review the literature systematically to identify and evaluate the various modalities available to record the NHP in 3 dimensions and to compare their accuracy.

MATERIALS AND METHODS

A systematic literature search of the PubMed, Cochrane Library and Embase databases, with no limitations on publication time or language, was performed in July 2015. The search and evaluations of articles were performed in 4 rounds. The methodologies, accuracies, advantages, and limitations of various modalities to record NHP were examined.

RESULTS

Eight articles were included in the final review. Six modalities to record NHP were identified, namely 1) stereophotogrammetry, 2) facial markings along laser lines, 3) clinical photographs and the pose from orthography and scaling with iterations (POSIT) algorithm, 4) digital orientation sensing, 5) handheld 3D camera measuring system, and 6) laser scanning. Digital orientation sensing had good accuracy, with mean angular differences from the reference within 1° (0.07 ± 0.49° and 0.12 ± 0.54°, respectively). Laser scanning was shown to be comparable to digital orientation sensing. The method involving clinical photographs and the POSIT algorithm was reported to have good accuracy, with mean angular differences for pitch, roll, and yaw within 1° (-0.17 ± 0.50°). Stereophotogrammetry was reported to have the highest reliability, with mean angular deviations in pitch, roll, and yaw for active and passive stereophotogrammetric devices within 0.1° (0.004771 ± 0.045645° and 0.007572 ± 0.079088°, respectively).

CONCLUSIONS

This systematic review showed that recording the NHP in 3 dimensions with a digital orientation sensor has good accuracy. Laser scanning was found to have comparable accuracy to digital orientation sensing, but routine clinical use was limited by its high cost and low portability. Stereophotogrammetry and the method using a single clinical photograph and the POSIT algorithm were potential alternatives. Nevertheless, clinical trials are needed to verify their applications in patients. Preferably, digital orientation sensor should be used as a reference for comparison with new proposed methods of recording the NHP in future research.

Determine the effect of neck muscle fatigue on dynamic visual acuity in healthy young adults

[Purpose] The aim of this study was to determine whether neck muscle fatigue affects dynamic visual acuity in healthy young participants. [Subjects and Methods] This study was a double-blinded, prospective, randomized, controlled trial. Thirty healthy young subjects (ages 21 to 30 years) participated in the study. Participants were randomly divided into an experimental group (n=15) and a control group (n=15). The experimental group performed an exercise designed to induce neck muscle fatigue and the control group preformed non-fatiguing sham exercises. [Results] There were significant differences in mean dynamic visual acuity between the two groups (0.26±0.11 LogMar versus 0.003±0.02 LogMar). Subjects in the experimental group showed a significant decline in their dynamic visual acuity compared with the control group. Dynamic visual acuity strongly correlated with neck muscle fatigue (r = 0.79). No significant differences in joint position error were observed between the two groups and no significant correlations between joint position error and neck muscle fatigue were observed (r = 0.23). [Conclusion] The results of this study suggest that neck muscle fatigue negatively impacts dynamic visual acuity. Although not statistically significant, cervical spine proprioception as measured by the joint position error in the experimental group was diminished after fatigue.

Effects of muscle fatigue on multi-muscle synergies

We studied the effects of fatigue of ankle dorsiflexors on multi-muscle synergies defined as co-varied adjustments of elemental variables (M-modes) that stabilize a task-related performance variable (trajectory of the center of pressure, COP). M-modes were defined as muscle groups with parallel changes in activation levels. Healthy participants performed voluntary body sway in the anterior-posterior direction while trying to minimize sway in the medio-lateral direction at 0.25, 0.5, and 0.75 Hz. The trials were repeated before and during fatigue induced with a timed voluntary contraction against a constant load. Factor extraction using the principal component method was used to identify four M-modes within the space of integrated indices of muscle activity. Variance in the M-mode space at different phases across sway cycles was partitioned into two components, one that did not affect the average value of COP shift and the other that did. There were no significant effects of fatigue on variability of performance of the explicit task and on the amplitude of the COP shift. Variance of muscle activation indices and M-mode magnitudes increased during fatigue for muscles (and M-modes) both involved and not involved in the fatiguing exercise. Most of the M-mode variance increase was within the sub-space compatible with the unchanged COP trajectory resulting in an increase of the index of the multi-M-mode synergy. We conclude that one of the adaptive mechanisms to fatigue within a redundant multi-muscle system involves an increase in the variance of activation of non-fatigued muscles with a simultaneous increase in co-variation among muscle activations. The findings can be interpreted within the referent configuration hypothesis on the control of whole-body actions.

Effects of vision and tactile stimulation of the neck on postural control during unperturbed stance and cervical joint position sense in young asymptomatic adults

STUDY DESIGN

Before and after intervention trials.

OBJECTIVE

To evaluate the effects of visual input and tactile stimulation of the neck on postural control during unperturbed stance and cervical joint position sense.

SUMMARY OF BACKGROUND DATA

Although beneficial effects on lower-limb joints proprioception have been reported when vision was available and when tactile stimulation was applied around lower-limb joints, there has hitherto been no study investigating whether and how vision and tactile stimulation applied to the neck could modify postural control during unperturbed stance and joint position sense.

METHODS

The effects of visual input and tactile stimulation of the neck on postural control during unperturbed stance (Experiments 1 and 2) and cervical joint position sense (Experiments 3 and 4) were assessed in four separate experiments. During these experiments, two experimental tasks (a postural task during unperturbed stance and the CRT to NHP) were executed without (No vision) and with the availability of the vision (Vision) and without (No tactile stimulation condition) and with the application of strips of adhesive bandage to the skin over and around the neck (Tactile stimulation condition). Twelve different subjects participated in the four experiments.

RESULTS

For experiments 1 and 2, decreased centre of foot pressure displacements were observed in the Vision relative to the No vision and in the Tactile stimulation relative to the No tactile stimulation condition. For experiments 3 and 4, more accurate and more consistent repositioning performances were observed in the Vision relative to the No vision and in the Tactile stimulation relative to the No tactile stimulation condition, as indicated by decreased absolute and variable errors, respectively.

CONCLUSION

Altogether, our results suggest that subjects were able to take advantage of vision and increased neck cutaneous information provided by the by strips of adhesive bandage applied to the neck to improve postural control during unperturbed stance and cervical joint position sense.