Proprioception of the shoulder after stroke

Impaired proprioception and magnified scaling of proprioceptive error responses in chronic stroke

BACKGROUND

Previous work has shown that ~ 50-60% of individuals have impaired proprioception after stroke. Typically, these studies have identified proprioceptive impairments using a narrow range of reference movements. While this has been important for identifying the prevalence of proprioceptive impairments, it is unknown whether these error responses are consistent for a broad range of reference movements. The objective of this study was to characterize proprioceptive accuracy as function of movement speed and distance in stroke.

METHODS

Stroke (N = 25) and controls (N = 21) completed a robotic proprioception test that varied movement speed and distance. Participants mirror-matched various reference movement speeds (0.1-0.4 m/s) and distances (7.5-17.5 cm). Spatial and temporal parameters known to quantify proprioception were used to determine group differences in proprioceptive accuracy, and whether patterns of proprioceptive error were consistent across testing conditions within and across groups.

RESULTS

Overall, we found that stroke participants had impaired proprioception compared to controls. Proprioceptive errors related to tested reference movement scaled similarly to controls, but some errors showed amplified scaling (e.g., significantly overshooting or undershooting reference speed). Further, interaction effects were present for speed and distance reference combinations at the extremes of the testing distribution.

CONCLUSIONS

We found that stroke participants have impaired proprioception and that some proprioceptive errors were dependent on characteristics of the movement (e.g., speed) and that reference movements at the extremes of the testing distribution resulted in significantly larger proprioceptive errors for the stroke group. Understanding how sensory information is utilized across a broad spectrum of movements after stroke may aid design of rehabilitation programs.

Multi-joint Assessment of Proprioception Impairments Poststroke

OBJECTIVES

To investigate shoulder, elbow and wrist proprioception impairment poststroke.

DESIGN

Proprioceptive acuity in terms of the threshold detection to passive motion at the shoulder, elbow and wrist joints was evaluated using an exoskeleton robot to the individual joints slowly in either inward or outward direction.

SETTING

A university research laboratory.

PARTICIPANTS

Seventeen stroke survivors and 17 healthy controls (N=34). Inclusion criteria of stroke survivors were (1) a single stroke; (2) stroke duration <1 year; and (3) cognitive ability to follow simple instructions.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Threshold detection to passive motion and detection error at the shoulder, elbow and wrist.

RESULTS

There was significant impairment of proprioceptive acuity in stroke survivors as compared to healthy group at all 3 joints and in both the inward (shoulder horizontal adduction, elbow and wrist flexion, P<.01) and outward (P<.01) motion. Furthermore, the distal wrist joint showed more severe impairment in proprioception than the proximal shoulder and elbow joints poststroke (P<.01) in inward motion. Stroke survivors showed significantly larger detection error in identifying the individual joint in motion (P<.01) and the movement direction (P<.01) as compared to the healthy group. There were significant correlations among the proprioception acuity across the shoulder, elbow and wrist joints and 2 movement directions poststroke.

CONCLUSIONS

There were significant proprioceptive sensory impairments across the shoulder, elbow and wrist joints poststroke, especially at the distal wrist joint. Accurate evaluations of multi-joint proprioception deficit may help guide more focused rehabilitation.

Reliability and validity of the trunk position sense and modified functional reach tests in individuals after stroke

The psychometric qualities of the proprioception and dynamic trunk control tests have rarely been studied in individuals after stroke.

OBJECTIVE

To investigate the reliability and validity of the Trunk Position Sense Test (TPS) and Modified Functional Reach Test (MFRT) in persons after stroke.

METHODS

Thirty-two participants were included. The TPS and MFRT were assessed by two physiotherapists during a first session. After resting, a second session was conducted. The intraclass correlation coefficient (ICC) was calculated to assess the test-retest (ICC3,k) and inter-rater reliability (ICC2,k). Pearson correlations coefficients were calculated between TPS/MFRT performances and clinical tests (trunk strength, Timed Up and Go and Balance Assessment in Sitting and Standing Positions - BASSP).

RESULTS

The TPS inter-rater reliability was good for vertical error (ICC = 0.75 [0.50-0.88]) while it was moderate for horizontal error (ICC = 0.48 [0.10-0.75]) as well as for test-retest reliability (0.39 ≤ ICC ≤ 0.59). As for the MFRT, inter-rater (0.76 ≤ ICC ≤ 0.90) and test-retest reliability (0.71 ≤ ICC ≤ 0.91) were good to excellent for anterior, paretic et non-paretic displacements. Horizontal errors for the TPS (-0.26 ≤ r ≤ -0.36) and anterior MFRT (0.38 ≤ r ≤ 0.64) values correlated moderately with trunk strength.

CONCLUSION

The MFRT is a reliable test for persons after stroke with trunk control impairments. The TPS does not appear to be relevant for post-stroke individuals. This can be explained by the fact that its procedure is not easily applied for individuals after stroke - who may have significant motor and cognitive impairments.

Assessing bilateral ankle proprioceptive acuity in stroke survivors: An exploratory study

Background

Bilateral proprioception deficits were reported in stroke survivors. However, whether bilateral proprioception deficits exist in the ankle joint after stroke was unclear. Ankle proprioception is a significant predictor of balance dysfunction after stroke, and previous studies to date are lacking appropriate evaluation methods.

Objectives

We want to determine whether the active movement extent discrimination apparatus (AMEDA) is a reliable tool for assessing ankle proprioceptive acuity in stroke survivors and the presence of deficits in ankle proprioception on the affected and unaffected sides in patients after stroke.

Methods

Bilateral ankle proprioception was assessed in 20 stroke patients and 20 age-matched healthy controls using AMEDA. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC).

Results

The ICC in the affected and unaffected sides was 0.713 and 0.74, respectively. Analysis of variance revealed significant deficits in ankle proprioception in subacute stroke survivors vs. healthy controls (F = 2.719, p = 0.045). However, there were no significant differences in proprioception acuity scores between the affected and unaffected sides in patients after stroke (F = 1.14, p = 0.331).

Conclusions

Stroke survivors had bilateral deficits in ankle proprioceptive acuity during active movements compared with age-matched healthy controls, underscoring the need to evaluate these deficits on both sides of the body and develop effective sensorimotor rehabilitation methods for this patient population. The AMEDA can reliably determine bilateral ankle proprioceptive acuity in stroke survivors.

Vision and Visuomotor Performance Following Acute Ischemic Stroke

Background

As measurable sensory and motor deficits are key to the diagnosis of stroke, we investigated the value of objective tablet based vision and visuomotor capacity assessment in acute mild-moderate ischemic stroke (AIS) patients.

Methods

Sixty AIS patients (65 ± 14 years, 33 males) without pre-existing visual/neurological disorders and acuity better than 6/12 were tested at their bedside during the first week post-stroke and were compared to 40 controls (64 ± 11 years, 15 males). Visual field sensitivity, quantified as mean deviation (dB) and visual acuity (with and without luminance noise), were tested on MRFn (Melbourne Rapid Field-Neural) iPad application. Visuomotor capacity was assessed with the Lee-Ryan Eye-Hand Coordination (EHC) iPad application using a capacitive stylus for iPad held in the preferred hand.Time to trace 3 shapes and displacement errors (deviations of >3.5 mm from the shape) were recorded. Diagnostic capacity was considered with Receiver Operating Characteristics. Vision test outcomes were correlated with National Institutes of Health Stroke Scale (NIHSS) score at the admission.

Results

Of the 60 AIS patients, 58 grasped the iPad stylus in their preferred right hand even though 31 had left hemisphere lesions. Forty-one patients (68%) with better than 6/12 visual acuity (19 right, 19 left hemisphere and 3 multi-territorial lesions) returned significantly abnormal visual fields. The stroke group took significantly longer (AIS: 93.4 ± 60.1 s; Controls: 33.1 ± 11.5 s, p < 0.01) to complete EHC tracing and made larger displacements (AIS: 16,388 ± 36,367 mm; Controls: 2,620 ± 1,359 mm, p < 0.01) although both control and stroke groups made similar numbers of errors. EHC time was not significantly different between participants with R (n = 26, 84.3 ± 55.3 s) and L (n = 31, 101.3 ± 64.7 s) hemisphere lesions. NIHSS scores and EHC measures showed low correlations (Spearman R: −0.15, L: 0.17). ROC analysis of EHC and vision tests found high diagnostic specificity and sensitivity for a fail at EHC time, or visual field, or Acuity-in-noise (sensivity: 93%, specificity: 83%) that shows little relationship to NIHSS scores.

Conclusions

EHC time and vision test outcomes provide an easy and rapid bedside measure that complements existing clinical assessments in AIS. The low correlation between visual function, NIHSS scores and lesion site offers an expanded clinical view of changes following stroke.

Proprioception: How is it affected by shoulder pain? A systematic review

INTRODUCTION

Proprioception encompasses the submodalities of joint position sense (JPS), kinesthesia, sense of force, and velocity. Owing to the vast mobility of the shoulder, it heavily relies on an intact sense of proprioception. Moreover, shoulder injuries are associated with a decreased sense of proprioception. What remains unclear is how shoulder proprioception is affected by pain and competing nociceptive senses.

PURPOSE OF THE STUDY

To summarize the literature evaluating the relationship between pain and shoulder proprioception.

METHODS

A literature review was conducted from inception until 22 October 2018, using electronic databases (PubMed, Web of Science, Scopus, EBSCO, CINAHL, and Embase). Retrieved citations were screened for eligibility, and methodological quality was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Eleven studies were included (n = 447 participants with shoulder pain, n = 20 with experimentally induced pain [EIP]/n = 600 painful shoulders and n = 20 [EIP]). The mean methodological quality of the studies was good (76%). Five studies investigated active JPS, four investigated passive JPS, six investigated kinesthesia, sense of force was measured in one study, and no study investigated sense of velocity. There is moderate evidence for impaired kinesthesia and low evidence for reduced sense of force among painful shoulders. Conflicting evidence is seen for the other proprioceptive submodalities.

CONCLUSION

The overall impact of pain on shoulder JPS remains unclear, while moderate evidence for an affected sense of kinesthesia is possible. There is low evidence for an impaired sense of force among painful shoulders. Standardization between studies is lacking, limiting the range of our conclusions. Further investigation is required into well-controlled and pain-induced studies to better understand the influence of pain on shoulder proprioception.

Impacts of Stroke on Muscle Perceptions and Relationships with the Motor and Functional Performance of the Lower Extremities

Stroke results in paretic limb disabilities, but few studies have investigated the impacts of stroke on muscle perception deficits in multiaxis movements and related functional changes. Therefore, this study aimed to investigate stroke-related changes in muscle perceptions using a multiaxis ankle haptic interface and analyze their relationships with various functions. Sixteen stroke patients and 22 healthy participants performed active reproduction tests in multiaxis movements involving the tibialis anterior (TA), extensor digitorum longus (EDL), peroneus longus, and flexor digitorum longus (FDL) of the ankle joint. The direction error (DE), absolute error (AE), and variable error (VE) were calculated. The lower extremity of Fugl-Meyer Assessment (FMA-LE), Barthel Index (BI), Postural Assessment Scale for Stroke Patients, Tinetti Performance-Oriented Mobility Assessment (POMA), and 10-m walk test (10MWT) were evaluated. VE of EDL for the paretic ankle was significantly lower than that for the nonparetic ankle (p = 0.009). AE of TA, EDL, and FDL and VE of EDL and FDL of muscle perceptions were significantly lower in healthy participants than in stroke patients (p < 0.05 for both). DE of TA for the paretic ankle was moderately correlated with FMA-LE (r = -0.509) and POMA (r = -0.619) scores. AE and VE of EDL for the paretic ankle were moderately correlated with the 10MWT score (r = 0.515 vs. 0.557). AE of FDL for the paretic ankle was also moderately correlated with BI (r = -0.562). This study indicated poorer accuracy and consistency in muscle perception for paretic ankles, which correlated with lower limb functions of stroke patients.

Patterns of enhancement in paretic shoulder kinematics after stroke with musical cueing

Musical cueing has been widely utilised in post-stroke motor rehabilitation; however, the kinematic evidence on the effects of musical cueing is sparse. Further, the element-specific effects of musical cueing on upper-limb movements have rarely been investigated. This study aimed to kinematically quantify the effects of no auditory, rhythmic auditory, and melodic auditory cueing on shoulder abduction, holding, and adduction in patients who had experienced hemiparetic stroke. Kinematic data were obtained using inertial measurement units embedded in wearable bands. During the holding phase, melodic auditory cueing significantly increased the minimum Euler angle and decreased the range of motion compared with the other types of cueing. Further, the root mean square error in the angle measurements was significantly smaller and the duration of movement execution was significantly shorter during the holding phase when melodic auditory cueing was provided than when the other types of cueing were used. These findings indicated the important role of melodic auditory cueing for enhancing movement positioning, variability, and endurance. This study provides the first kinematic evidence on the effects of melodic auditory cueing on kinematic enhancement, thus suggesting the potential use of pitch-related elements in psychomotor rehabilitation.

Isokinetic Analysis of Trunk Muscles in Stroke Patients and its Association with Functional Parameters

OBJECTIVE

The purpose of our study is to investigate the association of balance, motor and functional development parameters with trunk muscles via isokinetic analysis in stroke patients due to cerebrovascular event.

METHODS

The study included 91 stroke patients and 28 healthy controls. Brunnstroom staging (BS) for motor functions, functional independence measurement (FIM) and Barthel index (BI) for disability, Berg balance scale (BBS) balance test for balance, Rivermead motor evaluation (RMA) for mobility, and mini-mental test (MMT) for cognitive function were used. Strength and proprioception measurements of patients and controls' trunk extensor and flexor muscles were evaluated via exercise system and isokinetic test.

RESULTS

A strong positive correlation was found between FIM total score and lower-extremity Brunnstrom staging (p < 0.001). A strong positive correlation was found between trunk control test (TCT), and FIM total scores (p < 0.001, r = 0.892), BI (p < 0.001, r = 0.799) and BBS (p = 0.01, r = 0.885). Isokinetic muscle strength values of controls were found statistically significantly higher than those in patients with stroke (p < 0.001). Trunk control and proprioception were poor in patients with stroke compared to the control group (p <0.001). Trunk muscles performance measures were significantly associated with balance and functional parameters. However, no significant relationship was found between the angular values of trunk muscle proprioception and clinical parameters in patients with stroke.

CONCLUSIONS

In stroke patients, trunk muscles were weak and trunk proprioception was impaired. So, inserting exercise programs to strengthen trunk muscles and improve trunk proprioception through isokinetic dynamometers or conventional methods into the rehabilitation programs of patients with muscle weakness and proprioception disorder may provide a better functional development.

Shoulder pain after recent stroke (SPARS): hemiplegic shoulder pain incidence within 72hours post-stroke and 8-10 week follow-up (NCT 02574000)

OBJECTIVES

This study aimed to identify very early incidence of hemiplegic shoulder pain within 72hours (HSP), how clinical assessment was related to pain at 8-10 week follow-up and explore current standard therapy/management.

DESIGN

Observational, prospective.

SETTING

Teaching hospital hyper-acute and follow-up stroke services.

PARTICIPANTS

121 consecutive patients with confirmed cerebral infarct/haemorrhage recruited within 72hours of stroke onset.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Subjective report of pain severity and aggravating factors: using numerical rating scales and pain questionnaire (ShoulderQ), shoulder abductor and flexor muscle strength (Oxford MRC Scale), Neer's Test of sub-acromial pain, shoulder subluxation and soft tissue shoulder palpation.

RESULTS

At initial assessment (<72hours), 35% (42/121) reported HSP. At follow-up (8-10 weeks), 44% (53/121) had pain: pain persisted in 32 of the original 42, resolved in 10 and had developed since initial assessment in 21. Pain at follow-up was associated with a statistically significant higher frequency of severe shoulder muscle weakness (MRC grade ≤2) and gleno-humeral subluxation at initial assessment. Soft tissue palpation and Neer's Test detected pain but did not predict development of HSP. 50/121 patients had 140 therapy interventions, particularly targeted to those with a higher HSP risk.

CONCLUSION

This study reports HSP at an earlier time point after stroke than previous publications. Patients with severe arm weakness and/or shoulder subluxation within 72hours are at significantly higher risk of HSP at 8-10 weeks. These data highlight the high incidence of HSP, the non-standardized therapy approach, and can inform sample size calculations for future intervention studies.

CLINICAL TRIAL REGISTRATION

NCT02574000 (clinicaltrials.gov).

The Effects of Active Shoulder Exercise with a Sling Suspension System on Shoulder Subluxation, Proprioception, and Upper Extremity Function in Patients with Acute Stroke

BACKGROUND The aim of this study was to investigate the effect of active shoulder exercise with a sling suspension system on shoulder subluxation, proprioception, and upper extremity function in patients with acute stroke. MATERIAL AND METHODS Thirty-six patients with acute stroke and shoulder subluxation were randomly assigned into two groups. The study group (n=18) received active shoulder exercise with a sling suspension system, and the control group (n=18) received bilateral arm training for 40 minutes, for five days a week, for four weeks. The outcome measures before and after the intervention included measurement of shoulder subluxation distance, shoulder proprioception, the Fugl-Meyer assessment (FMA) scale, and the manual function test (MFT). RESULTS Comparison of the study group with the control group showed significant differences in all outcome scores post-intervention (p<0.05). The study group had significant improvement in shoulder subluxation distance, shoulder proprioception, the FMA score, and the MFT compared with the control group. There was a significant difference in shoulder subluxation (p=0.001), shoulder proprioception (p=0.046), the FMA score (p=0.002), and the MFT (p=0.007) between the two groups, which favored the study group. CONCLUSIONS Active shoulder exercise with a sling suspension system may be effective in reducing shoulder subluxation, improving proprioception, and upper extremity function in patients following acute stroke.

Quantitative evaluation of shoulder proprioception 6 months following stroke

Background

Chronic shoulder pain following cerebrovascular stroke (CVS) is a major problem that persists after maximum recovery of motor functions. Such pain has been attributed to altered shoulder joint kinematics causing soft tissue damage.

Aim

Evaluation of shoulder proprioception in the ipsilateral paretic arm and contralateral unaffected side 6 months following cerebrovascular event.

Subject and method

Thirty adult patients (G1) with ischemic strokes ranging from 6 months to 1 year and 30 healthy control (G2) were assessed for shoulder proprioception. Angular displacement error was measured during active and passive repositioning of shoulder external and internal rotation in both patients’ shoulders and in control’s dominant upper limb.

Results

Statistically significant increase in angular displacement error was found in all tests in the affected shoulder compared to the unaffected contralateral shoulder and dominant arm of control subjects. The contralateral unaffected shoulder of patients showed within normal values and no differences with control values. Passive external and internal rotations showed statistically higher errors in patients with cortical lesions compared to those with subcortical lesions.

Conclusion

Six months following the CVS, shoulder proprioception deficit in the affected hemiparetic side persists. Contralateral side shows no abnormalities. Cortical lesions might be associated with late shoulder proprioception recovery compared to subcortical lesions. The side of the lesion does not seem to affect the severity of proprioception deficit.

Ability of individuals with chronic hemiparetic stroke to locate their forearms during single-arm and between-arms tasks

Background

According to between-arms assessments, more than 50% of individuals with stroke have an impaired position sense. Our previous work, which employed a clinical assessment and slightly differing tasks, indicates that individuals who have a deficit on a between-forearms position-localization task do not necessarily have a deficit on a single-forearm position-localization task.

Objective

Our goal here was to, using robotics tools, determine whether individuals with stroke who have a deficit when matching forearm positions within an arm also have a deficit when mirroring forearm positions between arms, independent of the arm that leads the task.

Methods

Eighteen participants with chronic hemiparetic stroke and nine controls completed a single-arm position-matching experiment and between-arms position-mirroring experiment. For each experiment, the reference forearm (left/right) passively rotated about the elbow joint to a reference target location (flexion/extension), and then the participant actively rotated their same/opposite forearm to match/mirror the reference forearm’s position. Participants with stroke were classified as having a position-matching/-mirroring deficit based on a quantitative threshold that was derived from the controls’ data.

Results

On our single-arm task, one participant with stroke was classified as having a position-matching deficit with a mean magnitude of error greater than 10.7° when referencing their paretic arm. Position-matching ability did not significantly differ for the controls and the remaining seventeen participants with stroke. On our between-arms task, seven participants with stroke were classified as having a position-mirroring deficit with a mean magnitude of error greater than 10.1°. Position-mirroring accuracy was worse for these participants with stroke, when referencing their paretic arm, than the controls.

Concluding remark

Findings underscore the need for assessing within-arm position-matching deficits, in addition to between-arms position-mirroring deficits when referencing each arm, to comprehensively evaluate an individual’s ability to locate their forearm(s).

Proprioceptive assessment in clinical settings: Evaluation of joint position sense in upper limb post-stroke using a robotic manipulator

Proprioception is a critical component for motor functions and directly affects motor learning after neurological injuries. Conventional methods for its assessment are generally ordinal in nature and hence lack sensitivity. Robotic devices designed to promote sensorimotor learning can potentially provide quantitative precise, accurate, and reliable assessments of sensory impairments. In this paper, we investigate the clinical applicability and validity of using a planar 2 degrees of freedom robot to quantitatively assess proprioceptive deficits in post-stroke participants. Nine stroke survivors and nine healthy subjects participated in the study. Participants’ hand was passively moved to the target position guided by the H-Man robot (Criterion movement) and were asked to indicate during a second passive movement towards the same target (Matching movement) when they felt that they matched the target position. The assessment was carried out on a planar surface for movements in the forward and oblique directions in the contralateral and ipsilateral sides of the tested arm. The matching performance was evaluated in terms of error magnitude (absolute and signed) and its variability. Stroke patients showed higher variability in the estimation of the target position compared to the healthy participants. Further, an effect of target was found, with lower absolute errors in the contralateral side. Pairwise comparison between individual stroke participant and control participants showed significant proprioceptive deficits in two patients. The proposed assessment of passive joint position sense was inherently simple and all participants, regardless of motor impairment level, could complete it in less than 10 minutes. Therefore, the method can potentially be carried out to detect changes in proprioceptive deficits in clinical settings.

The Arm Movement Detection (AMD) test: a fast robotic test of proprioceptive acuity in the arm

Background

We examined the validity and reliability of a short robotic test of upper limb proprioception, the Arm Movement Detection (AMD) test, which yields a ratio-scaled, objective outcome measure to be used for evaluating the impact of sensory deficits on impairments of motor control, motor adaptation and functional recovery in stroke survivors.

Methods

Subjects grasped the handle of a horizontal planar robot, with their arm and the robot hidden from view. The robot applied graded force perturbations, which produced small displacements of the handle. The AMD test required subjects to respond verbally to queries regarding whether or not they detected arm motions. Each participant completed ten, 60s trials; in five of the trials, force perturbations were increased in small increments until the participant detected motion while in the others, perturbations were decreased until the participant could no longer detect motion. The mean and standard deviation of the 10 movement detection thresholds were used to compute a Proprioceptive Acuity Score (PAS). Based on the sensitivity and consistency of the estimated thresholds, the PAS quantifies the likelihood that proprioception is intact. Lower PAS scores correspond to higher proprioceptive acuity. Thirty-nine participants completed the AMD test, consisting of 25 neurologically intact control participants (NIC), seven survivors of stroke with intact proprioception in the more affected limb (HSS+P), and seven survivors of stroke with impaired or absent proprioception in the more affected limb (HSS-P).

Results

Significant group differences were found, with the NIC and HSS+P groups having lower (i.e., better) PAS scores than the HSS-P group. A subset of the participants completed the AMD test multiple times and the AMD test was found to be reliable across repetitions.

Conclusions

The AMD test required less than 15 min to complete and provided an objective, ratio-scaled measure of proprioceptive acuity in the upper limb. In the future, this test could be utilized to evaluate the contributions of sensory deficits to motor recovery following stroke.

Electronic supplementary material

The online version of this article (doi:10.1186/s12984-017-0269-3) contains supplementary material, which is available to authorized users.

Subacromial Anesthetics Increase Proprioceptive Deficit in the Shoulder and Elbow in Patients With Subacromial Impingement Syndrome

Shoulder proprioception gives information regarding arm joint position and movement direction. Several studies have investigated shoulder proprioceptive acuity in patients with subacromial impingement syndrome (SIS); however, differences in protocols and between-subjects designs have limited scientific inferences regarding proprioception and SIS. We aimed to determine within-subject differences in shoulder and elbow proprioceptive acuity in 17 patients with stage 2 SIS following treatment of a local anesthetic injection. In addition, we used 17 healthy, age-, sex-, and arm dominance–matched controls to determine the magnitude of differences after treatment. Joint position sense (JPS) was measured before and after treatment in both groups in the sagittal plane for the shoulder and elbow. Our results indicate that patients with SIS have less sensitivity to angular position and tended to overshoot their targets with greater variability during angle-matching tasks for the shoulder (1.8° difference, P = .042) and elbow (5.6° difference, P = .001) than controls. The disparities in JPS found in patients with SIS were not resolved following subacromial injection; in fact, the magnitude of the errors increased after treatment where postinjection errors were significantly greater (P = .046) than controls, with an average difference of 2.4°. These findings suggest that patients with SIS have decrements in either the signaling or processing of proprioceptive information and may use pain to reduce these inequalities.

Elastic Tape Improved Shoulder Joint Position Sense in Chronic Hemiparetic Subjects: A Randomized Sham-Controlled Crossover Study

Background

Elastic tape has been widely used in clinical practice in order to improve upper limb (UL) sensibility. However, there is little evidence that supports this type of intervention in stroke patients.

Objective

To verify the effect of elastic tape, applied to the paretic shoulder, on joint position sense (JPS) during abduction and flexion in subjects with chronic hemiparesis compared to sham tape (non-elastic tape). Furthermore, to verify if this potential effect is correlated to shoulder subluxation measurements and sensorimotor impairment.

Methods

A crossover and sham-controlled study was conducted with post-stroke patients who were randomly allocated into two groups: 1) those who received Sham Tape (ST) first and after one month they received Elastic Tape (ET); 2) those who received Elastic Tape (ET) first and after one month they received Sham Tape (ST). The JPS was evaluated using a dynamometer. The absolute error for shoulder abduction and flexion at 30° and 60° was calculated. Sensorimotor impairment was determined by Fugl-Meyer, and shoulder subluxation was measured using a caliper.

Results

Thirteen hemiparetic subjects (average time since stroke 75.23 months) participated in the study. At baseline (before interventions), the groups were not different for abduction at 30° (p = 0.805; p = 0.951), and 60° (p = 0.509; p = 0.799), or flexion at 30° (p = 0.872; p = 0.897) and 60° (p = 0.853; p = 0.970). For the ET group, differences between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° p<0.010) and 60° (p<0.010) were observed. For the ST group, differences were also observed between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° (p<0.010,) and 60° (p<0.010). Potential effects were only correlated with shoulder subluxation during abduction at 30° (p = 0.001, r = -0.92) and 60° (p = 0.020, r = -0.75).

Conclusion

Elastic tape improved shoulder JPS of subjects with chronic hemiparesis regardless of the level of UL sensorimotor impairment. However, this improvement was influenced by the subluxation degree at abduction.

Individuals with chronic hemiparetic stroke can correctly match forearm positions within a single arm

OBJECTIVE

Previous studies determined, using between arms position matching assessments, that at least one-half of individuals with stroke have an impaired position sense. We investigated whether individuals with chronic stroke who have impairments mirroring arm positions also have impairments identifying the location of each arm in space.

METHODS

Participants with chronic hemiparetic stroke and age-matched participants without neurological impairments (controls) performed a between forearms position matching task based on a clinical assessment and a single forearm position matching task, using passive and active movements, based on a robotic assessment.

RESULTS

12 out of our 14 participants with stroke who had clinically determined between forearms position matching impairments had greater errors than the controls in both their paretic and non-paretic arm when matching positions during passive movements; yet stroke participants performed comparable to the controls during active movements.

CONCLUSIONS

Many individuals with chronic stroke may have impairments matching positions in both their paretic and non-paretic arm if their arm is moved for them, yet not within either arm if these individuals control their own movements.

SIGNIFICANCE

The neural mechanisms governing arm location perception in the stroke population may differ depending on whether arm movements are made passively versus actively.

Torque steadiness and muscle activation are bilaterally impaired during shoulder abduction and flexion in chronic post-stroke subjects

OBJECTIVE

To characterize sensorimotor control and muscle activation in the shoulder of chronic hemiparetic during abduction and flexion in maximal and submaximal isometric contractions. Furthermore, to correlate submaximal sensorimotor control with motor impairment and degree of shoulder subluxation.

METHODS

Thirteen chronic hemiparetic post-stroke age-gender matched with healthy were included. Isometric torques were assessed using a dynamometer. Electromyographic activity of the anterior and middle deltoid, upper trapezius, pectoralis major and serratus anterior muscles were collected. Variables were calculated for torque: peak, time to target, standard deviation (SD), coefficient of variation (CV), and standard error (RMSE); for muscle activity: maximum and minimum values, range and coefficient of activation. Motor impairment was determined by Fugl-Meyer and shoulder subluxation was measured with a caliper.

RESULTS

Paretic and non-paretic limbs reduced peak and muscle activation during maximal isometric contraction. Paretic limb generated lower force when compared with non-paretic and control. Paretic and non-paretic presented higher values of SD, CV, RMSE, and CV for prime mover muscles and minimum values for all muscles during steadiness. No correlation was found between sensorimotor control, motor impairment and shoulder subluxation.

CONCLUSION

Chronic hemiparetic presented bilateral deficits in sensorimotor and muscle control during maximal and submaximal shoulder abduction and flexion.

Robotic Quantification of Position Sense in Children With Perinatal Stroke

Background Perinatal stroke is the leading cause of hemiparetic cerebral palsy. Motor deficits and their treatment are commonly emphasized in the literature. Sensory dysfunction may be an important contributor to disability, but it is difficult to measure accurately clinically. Objective Use robotics to quantify position sense deficits in hemiparetic children with perinatal stroke and determine their association with common clinical measures. Methods Case-control study. Participants were children aged 6 to 19 years with magnetic resonance imaging-confirmed unilateral perinatal arterial ischemic stroke or periventricular venous infarction and symptomatic hemiparetic cerebral palsy. Participants completed a position matching task using an exoskeleton robotic device (KINARM). Position matching variability, shift, and expansion/contraction area were measured with and without vision. Robotic outcomes were compared across stroke groups and controls and to clinical measures of disability (Assisting Hand Assessment) and sensory function. Results Forty stroke participants (22 arterial, 18 venous, median age 12 years, 43% female) were compared with 60 healthy controls. Position sense variability was impaired in arterial (6.01 ± 1.8 cm) and venous (5.42 ± 1.8 cm) stroke compared to controls (3.54 ± 0.9 cm, P < .001) with vision occluded. Impairment remained when vision was restored. Robotic measures correlated with functional disability. Sensitivity and specificity of clinical sensory tests were modest. Conclusions Robotic assessment of position sense is feasible in children with perinatal stroke. Impairment is common and worse in arterial lesions. Limited correction with vision suggests cortical sensory network dysfunction. Disordered position sense may represent a therapeutic target in hemiparetic cerebral palsy.

Quantification of Lower Extremity Kinesthesia Deficits Using a Robotic Exoskeleton in People With a Spinal Cord Injury

BACKGROUND

Our ability to sense movement is essential for motor control; however, the impact of kinesthesia deficits on functional recovery is not well monitored in the spinal cord injury (SCI) population. One problem is the lack of accurate and reliable tools to measure kinesthesia.

OBJECTIVE

The purpose of this study was to establish the validity and reliability of a quantitative robotic assessment tool to measure lower limb kinesthesia in people with SCI.

METHODS

Seventeen individuals with an incomplete SCI and 17 age-matched controls completed 2 robotic-based assessments of lower limb kinesthesia sense, separated by at least 1 week. The Lokomat, a lower limb robotic exoskeleton, was used to quantify the movement detection score bilaterally for the hip and knee joints. Four passive movement speeds (0.5, 1.0, 2.0, and 4.0 deg/s) were applied in both flexion and extension directions. Participants responded via pressing a joystick button when movement was felt.

RESULTS

The movement detection score was significantly greater in people with SCI compared with the control group, particularly at the slowest movement speed. The difference between groups was more pronounced among those classified as ASIA (American Spinal Injury Association) Impairment Scale B. Our measure showed high test-retest reliability and good internal consistency for the hip and knee joints.

CONCLUSIONS

Our findings demonstrated that lower limb kinesthesia deficits are common in the SCI population and highlighted the importance of valid and reliable tools to monitor sensory function. Future studies need to examine changes in sensory function in response to therapy.

Altered phalanx force direction during power grip following stroke

Many stroke survivors with severe impairment can grasp only with a power grip. Yet, little knowledge is available on altered power grip after stroke, other than reduced power grip strength. This study characterized stroke survivors' static power grip during 100 and 50 % maximum grip. Each phalanx force angular deviation from the normal direction and its contribution to total normal force was compared for 11 stroke survivors and 11 age-matched controls. Muscle activities and skin coefficient of friction were additionally compared for another 20 stroke and 13 age-matched control subjects. The main finding was that stroke survivors gripped with a 34 % greater phalanx force angular deviation of 19° ± 2° compared to controls of 14° ± 1° (p < .05). Stroke survivors' phalanx force angular deviation was closer to the 23° threshold of slippage between the phalanx and grip surface, which may explain increased likelihood of object dropping in stroke survivors. In addition, this altered phalanx force direction decreases normal grip force by tilting the force vector, indicating a partial role of phalanx force angular deviation in reduced grip strength post-stroke. Greater phalanx force angular deviation may biomechanically result from more severe underactivation of stroke survivors' first dorsal interosseous and extensor digitorum communis muscles compared to their flexor digitorum superficialis or somatosensory deficit. While stroke survivors' maximum power grip strength was approximately half of the controls, the distribution of their remaining strength over the fingers and phalanges did not differ, indicating evenly distributed grip force reduction over the entire hand.

Upper extremity proprioception in healthy aging and stroke populations, and the effects of therapist- and robot-based rehabilitation therapies on proprioceptive function

The world’s population is aging, with the number of people ages 65 or older expected to surpass 1.5 billion people, or 16% of the global total. As people age, there are notable declines in proprioception due to changes in the central and peripheral nervous systems. Moreover, the risk of stroke increases with age, with approximately two-thirds of stroke-related hospitalizations occurring in people over the age of 65. In this literature review, we first summarize behavioral studies investigating proprioceptive deficits in normally aging older adults and stroke patients, and discuss the differences in proprioceptive function between these populations. We then provide a state of the art review the literature regarding therapist- and robot-based rehabilitation of the upper extremity proprioceptive dysfunction in stroke populations and discuss avenues of future research.

Joint position sense is bilaterally reduced for shoulder abduction and flexion in chronic hemiparetic individuals

BACKGROUND

The stroke is the leading cause of adult disability in the world. One of the main complaints of individuals post-stroke refers to the loss of function of the upper limb, as evidenced during the performance of activities of daily living. This difficulty may be related to an important component of sensorimotor control, joint position sense, a submodality of proprioception.

OBJECTIVES

To investigate whether the proprioception of both shoulders of chronic hemiparetic patients is altered during abduction and flexion.

METHODS

Thirteen subjects with chronic hemiparesis due to ischemic stroke and 13 healthy subjects matched for gender and age was included. The joint sense position was assessed using a dynamometer. Absolute error for shoulder abduction and flexion at the 30 and 60° was calculated.

RESULTS

No difference was found between the paretic and non-paretic limbs in movements at both 30 and 60°. Higher values of absolute error for both paretic and non-paretic limbs compared to the control were observed during abduction at 30 and at 60°.

CONCLUSIONS

Chronic ischemic post-stroke patients have bilateral proprioceptive deficits in the shoulder during abduction and flexion. But these deficits are dependent on the movement performed and the angle tested. The results demonstrate the need to include bilateral exercises and/or visual feedback in the rehabilitation program.

Testing a Protocol for a Randomized Controlled Trial of Therapeutic versus Placebo Shoulder Strapping as an Adjuvant Intervention Early after Stroke

This study tested a protocol for a randomized controlled trial of therapeutic versus placebo shoulder strapping as an adjuvant intervention early after stroke. Despite widespread use, there is little evidence of the efficacy or acceptability of shoulder strapping to improve arm function in patients with shoulder paresis following stroke. This study tested a protocol designed to trial shoulder strapping as an adjuvant therapy in patients with shoulder paresis after stroke and tested its acceptability for patients and clinical staff. A multiple-method design comprised one quantitative randomized, double-blind, placebo-controlled study and two qualitative exploratory investigations entailing patient interviews and staff surveys. Seventeen sub-acute stroke patients with shoulder paresis were recruited in London stroke service settings between November 2007 and December 2009. Outcomes from a 4-week therapeutic strapping protocol were compared with those of placebo strapping as an adjunct to conventional rehabilitation. Minimal adverse events and greater improvement in arm function (Action Research Arm Test) were seen with therapeutic compared with placebo strapping (effect size 0.34). Patients and staff found the strapping acceptable with minimal adverse effects. This study provided data for sample size calculation and demonstrated a workable research protocol to investigate the efficacy of shoulder strapping as an adjuvant intervention to routine rehabilitation for stroke patients. Small-scale findings continue to flag the importance of investigating this topic. The protocol is recommended for a definitive trial of shoulder strapping as an adjuvant intervention.

Relationship between visuospatial neglect and kinesthetic deficits after stroke

BACKGROUND

After stroke, visuospatial and kinesthetic (sense of limb motion) deficits are common, occurring in approximately 30% and 60% of individuals, respectively. Although both types of deficits affect aspects of spatial processing necessary for daily function, few studies have investigated the relationship between these 2 deficits after stroke.

OBJECTIVE

We aimed to characterize the relationship between visuospatial and kinesthetic deficits after stroke using the Behavioral Inattention Test (BIT) and a robotic measure of kinesthetic function.

METHODS

Visuospatial attention (using the BIT) and kinesthesia (using robotics) were measured in 158 individuals an average of 18 days after stroke. In the kinesthetic matching task, the robot moved the participant's stroke-affected arm at a preset direction, speed, and magnitude. Participants mirror-matched the robotic movement with the less/unaffected arm as soon as they felt movement in their stroke affected arm.

RESULTS

We found that participants with visuospatial inattention (neglect) had impaired kinesthesia 100% of the time, whereas only 59% of participants without neglect were impaired. For those without neglect, we observed that a higher percentage of participants with lower but passing BIT scores displayed impaired kinesthetic behavior (78%) compared with those participants who scored perfect or nearly perfect on the BIT (49%).

CONCLUSIONS

The presence of visuospatial neglect after stroke is highly predictive of the presence of kinesthetic deficits. However, the presence of kinesthetic deficits does not necessarily always indicate the presence of visuospatial neglect. Our findings highlight the importance of assessment and treatment of kinesthetic deficits after stroke, especially in patients with visuospatial neglect.

A robotic test of proprioception within the hemiparetic arm post-stroke

Background

Proprioception plays important roles in planning and control of limb posture and movement. The impact of proprioceptive deficits on motor function post-stroke has been difficult to elucidate due to limitations in current tests of arm proprioception. Common clinical tests only provide ordinal assessment of proprioceptive integrity (eg. intact, impaired or absent). We introduce a standardized, quantitative method for evaluating proprioception within the arm on a continuous, ratio scale. We demonstrate the approach, which is based on signal detection theory of sensory psychophysics, in two tasks used to characterize motor function after stroke.

Methods

Hemiparetic stroke survivors and neurologically intact participants attempted to detect displacement- or force-perturbations robotically applied to their arm in a two-interval, two-alternative forced-choice test. A logistic psychometric function parameterized detection of limb perturbations. The shape of this function is determined by two parameters: one corresponds to a signal detection threshold and the other to variability of responses about that threshold. These two parameters define a space in which proprioceptive sensation post-stroke can be compared to that of neurologically-intact people. We used an auditory tone discrimination task to control for potential comprehension, attention and memory deficits.

Results

All but one stroke survivor demonstrated competence in performing two-alternative discrimination in the auditory training test. For the remaining stroke survivors, those with clinically identified proprioceptive deficits in the hemiparetic arm or hand had higher detection thresholds and exhibited greater response variability than individuals without proprioceptive deficits. We then identified a normative parameter space determined by the threshold and response variability data collected from neurologically intact participants. By plotting displacement detection performance within this normative space, stroke survivors with and without intact proprioception could be discriminated on a continuous scale that was sensitive to small performance variations, e.g. practice effects across days.

Conclusions

The proposed method uses robotic perturbations similar to those used in ongoing studies of motor function post-stroke. The approach is sensitive to small changes in the proprioceptive detection of hand motions. We expect this new robotic assessment will empower future studies to characterize how proprioceptive deficits compromise limb posture and movement control in stroke survivors.

Deficits in upper limb position sense of children with Spastic Hemiparetic Cerebral Palsy are distance-dependent

This study examined the arm position sense in children with Spastic Hemiparetic Cerebral Palsy (SHCP) and typically developing children (TD) by means of a contralateral matching task. This task required participants to match the position of one arm with the position of the other arm for different target distances and from different starting positions. Results showed that children with SHCP exhibited with both arms larger matching errors than the TD group, but only when the distance between the arms at the start of the movement was large. In addition, the difference in errors between the less-impaired and the impaired limb changed as a function of the distance in the SHCP group whereas no interlimb differences were found in the TD group. Finally, spasticity and restricted range of motion in children with SHCP were not related to the proportion of undershoot and size of absolute error. This suggests that SHCP could be associated with sensory problems in conjunction with their motor problems. In conclusion, the current study showed that accurate matching of the arms is greatly impaired in SHCP when compared to TD children, irrespective of which arm is used. Moreover, this deficit is particularly present for large movement amplitudes.

Joint position sense is not altered during shoulder medial and lateral rotations in female assembly line workers with shoulder impingement syndrome

This study evaluated joint position sense (JPS) during medial and lateral rotations of the shoulder in female workers with and without shoulder impingement syndrome (SIS). Three groups were assessed. The case group consisted of 15 female assembly line workers (35.5, SD 5.8 years) with unilateral SIS. Control group 1 consisted of 15 female assembly line workers asymptomatic for SIS (34.4, SD 5.5 years) and control group 2 consisted of 15 female subjects (33.1, SD 6.2 years) asymptomatic for SIS and with no exposure to activities with the upper limbs. The JPS was evaluated bilaterally during passive (2°/sec) and active (5°/sec) repositioning tests using an isokinetic dynamometer. The target angles were 45° of lateral rotation (achieved by medially rotating the shoulder from 90° of lateral rotation) and 75° of lateral rotation (achieved by laterally rotating the shoulder from neutral rotation). There were no differences between sides for all groups (p  >  0.05). There were no differences in any of the variables between the case group and the control groups (p  >  0.05). The results of this study suggest that JPS during medial and lateral rotations of the shoulder is not altered in female assembly line workers with SIS.

Three-dimensional shoulder complex kinematics in individuals with upper extremity impairment from chronic stroke

PURPOSE

To evaluate shoulder complex kinematics in persons with chronic upper extremity (UE) impairments due to stroke and determine if kinematics predicts motor function based on the Fugl-Meyer Motor Assessment (FMA).

METHODS

Sixteen stroke survivors with chronic UE impairments (age range = 46-80 years, male = 8, female = 8, mean (SD) 66 (40) months post-stroke) performed the UE portion of the FMA with the shoulder/elbow subscale (FM_se) documented. Three-dimensional kinematics of the shoulder complex was collected with the Motion Monitor™ (Innsport, Chicago, IL, USA). Participants performed three repetitions of arm elevation in the frontal, sagittal and self-selected planes. The third repetition was analyzed. Scapular and humeral kinematics were calculated in the self-selected plane. Scapulohumeral rhythm was analyzed at peak elevation. Backward stepwise regression analysis predicted kinematic contributions to the FM_se.

RESULTS

Mean (SD) FM_se score was 25.3 1(10.9). Peak humeral elevation ranged from 45.6° to 129.2° (median 106.7°). Scapulohumeral rhythm was 4.1:1 when humeral elevation ranged from 45° to 50°, 1.5:1 from 80° to 95° and 2.1:1 from 105° to 130°. Humeral elevation, scapular upward rotation and scapular internal rotation predicted 65.4% of FM_se score variability.

CONCLUSIONS

Persons with chronic UE impairments from stroke demonstrated reduced peak elevation and altered scapulohumeral rhythm. Three predictors of the FM_se were humeral elevation, scapular upward rotation and scapular internal rotation.

Measures of sensation in neurological conditions: a systematic review

Objective: To systematically review the psychometric properties and clinical utility of measures of sensation in neurological conditions to inform future research studies and clinical practice.

Data sources: Electronic databases (MEDLINE, CINAHL, EMBASE and AMED) were searched from their inception to December 2010.

Review methods: Search terms were used to identify articles that investigated any sensory measures in neurological conditions. Data about their psychometric properties and clinical utility were extracted and analyzed independently. The strength of the psychometric properties and clinical utility were assessed following recommendations. 1

Results: Sixteen sensory measures were identified. Inter-rater reliability and redundancy of testing protocols are particular issues for this area of assessment. Eleven were rejected because they were not available for a researcher or clinician to use. Of the remaining five measures, the Erasmus MC modifications of the Nottingham Sensory Assessment and the Sensory section of the Fugl–Meyer Assessment showed the best balance of clinical utility and psychometric properties.

Conclusion: Many measures of sensory impairment have been used in research but few have been fully developed to produce robust data and be easy to use. At present, the sensory section of the Fugl–Meyer Assessment and the Erasmus MC modifications of the Nottingham Sensory Assessment show the most effective balance of usability and robustness, when delivered according to the operating instructions.

Effects of wrist tendon vibration on arm tracking in people poststroke

The goal of this study was to evaluate the influence of wrist tendon vibration on a multijoint elbow/shoulder tracking task. We hypothesized that tendon vibration applied at the wrist musculature would improve upper arm tracking performance in chronic stroke survivors through increased, Ia-afferent feedback to the central nervous system (CNS). To test this hypothesis, 10 chronic stroke and 5 neurologically intact subjects grasped the handle of a planar robot as they tracked a target through a horizontal figure-8 pattern. A total of 36 trials were completed by each subject. During the middle trials, 70-Hz tendon vibration was applied at the wrist flexor tendons. Position, velocity, and electromyography data were evaluated to compare the quality of arm movements before, during, and after trials with concurrent vibration. Despite tracking a target that moved at a constant velocity, hand trajectories appeared to be segmented, displaying alternating intervals of acceleration and deceleration. Segments were identifiable in tangential velocity data as single-peaked, bell-shaped speed pulses. When tendon vibration was applied at the wrist musculature, stroke subjects experienced improved tracking performance in that hand path lengths and peak speed variability decreased, whereas movement smoothness increased. These performance improvements were accompanied by decreases in the muscle activity during movement. Possible mechanisms behind improved movement control in response to tendon vibration may include improved sensorimotor integration or improved cortical modulation of spinal reflex activity.

Proprioception in total, hemi- and reverse shoulder arthroplasty in 3D motion analyses: a prospective study

The aim of the study was to assess proprioception after shoulder arthroplasty. Twenty-six patients were enrolled who underwent total shoulder arthroplasty (TSA) (n = 13) or hemi-arthroplasty (n = 8) for shoulder osteoarthritis or reversed arthroplasty (n = 5) for cuff tear arthropathy. All patients were examined before the operation and then again six months thereafter in a motion analysis study with an active angle-reproduction (AAR) test. In all groups the AAR deteriorated at 60 degrees flexion (from 5.5 degrees [SD 2.8] to 7.6 degrees [SD 2.7]; p = 0.007) and at 30 degrees external rotation (ER) (from 6.5 degrees [SD 3.6] to 7.3 degrees [SD 4.8 degrees]; p = 0.023) six months after surgery. In the subgroup of TSA, there was deterioration at 30 degrees ER (p = 0.036). Otherwise, there were no significant changes within or among the subgroups. Proprioception, assessed by the AAR test, remained unchanged or deteriorated six months after shoulder arthroplasty. This might be related to the reduced pain or to the relatively short follow-up period.