The shoulder and elbow joints and right and left sides demonstrate similar joint position sense

Relationship between pain and proprioception among individuals with rotator cuff-related shoulder pain

BACKGROUND

Individuals with rotator cuff-related shoulder pain (RCRSP) have altered proprioception. The relationship between shoulder pain and proprioception is not well understood.

PURPOSE

This study aimed to investigate the relationship between shoulder pain and proprioception.

STUDY DESIGN

This was a cross-sectional comparative study.

METHODS

Twenty-two participants with RCRSP (mean age 27.6 ± 4.8 years) and 22 matched pain-free participants (23.4 ± 2.5 years) performed two upper limb active joint position sense tests: (1) the Upper Limb Proprioception Reaching Test (PRO-Reach; reaching toward seven targets) in centimeters and (2) Biodex System at 90% of maximum internal rotation in degrees. Participants performed three memorization and three reproduction trials blindfolded. The proprioception error (PE) is the difference between the memorized and estimation trials. Pain levels were captured pre- and post-evaluation (11-point Likert Numerical Pain Rating Scale). Relationships between PE and pain were investigated using independent t-tests and Spearman rank correlations.

RESULTS

Overall, 22.7% RCRSP participants indicated an increase in pain following the PRO-Reach (X̅ increase of 1.4 ± 1.5 points), while 59% did so with the Biodex (X̅ increase of 2.3 ± 1.8 points), reflecting a clinically important increase in pain. Weak-to-moderate correlations between pain and PEs were found with the Biodex (r = 0.39-0.53) and weak correlations with the PRO-Reach (r = -0.26 to 0.38). Concerning PEs, no significant differences were found between groups with the Biodex (p = 0.32, effect size d = -0.31 [-0.90 to 0.29]). The RCRSP participants demonstrated lower PEs with the PRO-Reach in elevation compared to pain-free participants (global X̅ = 4.6 ± 1.2 cm vs 5.5 ± 1.5 cm; superior 3.8 ± 2.1 cm vs 5.7 ± 2.9 cm; superior-lateral nondominant targets 4.3 ± 2.2 cm vs 6.1 ± 2.8 cm; p = 0.02-0.05, effect size d = 0.72-0.74 [0.12-1.3]).

CONCLUSIONS

Individuals with RCRSP demonstrated better upper limb proprioception in elevation, suggesting a change to interoception (sensory reweighting) in the presence of pain.

Grip force makes wrist joint position sense worse

Background

The purpose of this study was to investigate how grip force affects wrist joint position sense.

Methods

Twenty-two healthy participants (11 men and 11 women) underwent an ipsilateral wrist joint reposition test at 2 distinct grip forces [0 and 15% of maximal voluntary isometric contraction (MVIC)] and 6 different wrist positions (pronation 24°, supination 24°, radial deviation 16°, ulnar deviation 16°, extension 32°, and flexion 32°).

Results

The findings demonstrated significantly elevated absolute error values at 15% MVIC (3.8 ± 0.3°) than at 0% MVIC grip force [3.1 ± 0.2°, t(20) = 2.303, P = 0.032].

Conclusion

These findings demonstrated that there was significantly worse proprioceptive accuracy at 15% MVIC than at 0% MVIC grip force. These results may contribute to a better comprehension of the mechanisms underlying wrist joint injuries, the development of preventative measures to lower the risk of injuries, and the best possible design of engineering or rehabilitation devices.

Assessment of shoulder proprioception in patients with chronic mechanical cervical pain: A comparative study

BACKGROUND

Chronic mechanical cervical pain (CMCP) is a common disabling problem worldwide, interfering with upper extremities function. However studying the impact of CMCP on shoulder proprioception is still lacking.

OBJECTIVE

To investigate the impact of CMCP on shoulder proprioception in young adults compared with normal control (NC) individuals.

METHODS

A comparative study was conducted between two groups; 40 patients with CMCP (mean age 32.28 ± 6.586) and 40 age and sex matched NC (mean age 33.43 ± 9.021). The Biodex isokinetic dynamometer was used to assess shoulder active sense of position at 30∘ external and internal rotations. The absolute angular error was calculated for the dominant and non-dominant shoulders.

RESULTS

The absolute angular error was significantly increased only in the CMCP at both rotation angles for both shoulders, showing a remarkable increase on the dominant shoulder and in the external rotation range compared with NC.

CONCLUSIONS

CMCP can significantly impair shoulder proprioception, particularly on the dominant side and in external rotation range. This could emphasize the careful examination of shoulder proprioception for the early detection of shoulders at risk, to eliminate the possibility of shoulder instability and/or injury in young adults with CMCP.

Joint Specificity and Lateralization of Upper Limb Proprioceptive Perception

Proprioception is the sense of position and movement of body segments. The widespread distribution of proprioceptors in human anatomy raises questions about proprioceptive uniformity across different body parts. For the upper limbs, previous research, using mostly active and/or contralateral matching tasks, has suggested better proprioception of the non-preferred arm, and at the elbow rather than the wrist. Here we assessed proprioceptive perception through an ipsilateral passive matching task by comparing the elbow and wrist joints of the preferred and non-preferred arms. We hypothesized that upper limb proprioception would be better at the elbow of the non-preferred arm. We found signed errors to be less variable at the non-preferred elbow than at the preferred elbow and both wrists. Signed errors at the elbow were also more stable than at the wrist. Across individuals, signed errors at the preferred and non-preferred elbows were correlated. Also, variable signed errors at the preferred wrist, non-preferred wrist, and preferred elbow were correlated. These correlations suggest that an individual with relatively consistent matching errors at one joint may have relatively consistent matching errors at another joint. Our findings also support the view that proprioceptive perception varies across upper limb joints, meaning that a single joint assessment is insufficient to provide a general assessment of an individual's proprioception.

Laser-Pointer assisted angle reproduction test (LP-ART): reliability, performance, and correlation with shoulder pain and disability in patients with subacromial pain syndrome

INTRODUCTION

The proprioception plays an important role in the stability of the shoulder joint. However, clinical practice lacks reliable and user-friendly tools.

OBJECTIVES

To evaluate the intra- and inter-rater reliability of the Laser-Pointer assisted Angle Reproduction Test (LP-ART), to analyze the difference in proprioception between the symptomatic and asymptomatic shoulders, and to investigate if there is a correlation between the LP-ART and the pain intensity assessed by 11-point Numerical Rating Pain Scale (NRPS) and the level of shoulder disability and pain assessed by the Disability Index and Shoulder Pain (SPADI - BR).

METHODS

Fifty patients (age = 56.2 ± 10.4 years) performed the LP-ART at 90° of shoulder flexion.

RESULTS

The intra and interrater reliability of the LP-ART measurements was moderate (Intraclass Correlation Coefficient_2,3 = 0.41 to 0.65) for both shoulders, symptomatic and asymptomatic. There was no difference in the absolute angular deviation between shoulders (mean difference of 0.4°, P = .581). The absolute angular deviation was not significantly correlated with the pain intensity (rs = 0.007, P = .962) and the SPADI - BR (r_s = 0.022, P = .881).

CONCLUSION

The LP-ART measurement showed moderate reliability in participants with subacromial pain syndrome. The active joint position sense was not different between symptomatic and asymptomatic shoulders, and there was no correlation between proprioception and the pain intensity and shoulder pain and disability level.

Joint Position Accuracy Is Influenced by Visuoproprioceptive Congruency in Virtual Reality

Weighted integration of visual and proprioceptive information is important in movement planning and execution. The present study used a virtual reality system to determine how upper limb movement consistency and accuracy are altered when (a) vision of the limb is removed and (b) proprioception and vision of the limb are misaligned. A one degree of freedom upper limb movement task was performed under three visual conditions of the limb; accurate vision, no vision, and offset vision. Movement consistency was unaltered by the change in visual condition. Compared to the accurate vision condition, movement accuracy was unchanged in the no vision condition but decreased with a visual offset. When available, vision was relied upon more heavily than proprioception for task completion.

INFLUENCE OF FOAM ROLLING ON ELBOW PROPRIOCEPTION, STRENGTH, AND FUNCTIONAL MOTOR PERFORMANCE

CONTEXT

Foam rolling has recently been used frequently to increase flexibility. However, its effects on proprioception, strength and motor performance are not well known. In addition, very few studies have examined the effects of foam rolling in the upper extremity.

OBJECTIVE

To investigate the effects of foam rolling on elbow proprioception, strength, and functional motor performance in healthy individuals.

DESIGN

Randomized controlled study.

SETTING

Exercise laboratory of X Department, X University.

PATIENTS OR OTHER PARTICIPANTS

Sixty healthy participants (mean age=22.83±4.07 years).

INTERVENTION(S)

We randomly assigned participants into two groups: the foam rolling group (FRG) (4 weeks of foam rolling for the biceps brachii muscle) and control group (CG) (no foam rolling).

MAIN OUTCOME MEASURE(S)

We evaluated proprioception (joint position sense [JPS] and force matching), biceps brachii muscle strength, and functional motor performance (modified pull-up test [MPUT], closed kinetic chain upper extremity stability test [CKCUEST], and push-up test) at the baseline, and at the end of the 4th week and 8th week.

RESULTS

JPS at 45° elbow flexion, muscle strength, CKCUEST, and push-up test results improved after foam rolling and improvement was maintained at the follow-up (p<0.017). While the changes in groups for the results of proprioception and CKCUEST were similar among the three time points (p>0.05), there were significant improvements for the muscle strength from baseline to the second evaluation, and from baseline to the follow-up (p<0.001) in the FRG compared to the CG (p=0.004). The FRG was superior to the CG in the improvement of push-up test results among the three time points (p=0.040, p=0.001, p<0.001). Other data did not change (p>0.05).

CONCLUSION

Foam rolling is effective in improving elbow JPS in small flexion angles, biceps brachii strength, and some parameters of upper extremity functional motor performance. These effects are maintained 4 weeks after application.

Shoulder Joint Position Sense Can Be Reduced by Sensory Reference Frame Transformations

Joint position sense (JPS) is commonly evaluated using an angle replication protocol with vision occluded. However, multiple sources of sensory information are integrated when moving limbs accurately, not just proprioception. The purpose of this study was to examine different availability of vision during an active JPS protocol at the shoulder. Specifically, the effects of four conditions of vision availability were examined for three target shoulder elevation angles (50°, 70° & 90°): vision occluded continuously (P-P); vision available continuously (VP-VP); vision occluded only during target memorization (P-VP); and vision occluded only during target position replication (VP-P). There were 18 participants (M age = 21, SD = 1 years). We used separate repeated ANOVAs to examine the effect of condition and target angle on participants' absolute error (AE, a measure of accuracy) and constant error (CE, a measure of directional bias). We found a significant main effect for condition and angle for both dependent variables (p < 0.01), and follow-up analysis indicated that participants were most accurate in the VP-VP condition and least accurate in the P-VP condition. Further follow-up analysis showed that accuracy improved with higher target elevation angles, consistent with previous research findings. Constant error results were similar, as there was a prominent tendency to overshoot the target. Unsurprisingly, participants performed best at the angle replication protocol with their eyes open. However, while accuracy was reduced when vision was occluded during target memorization, it was restored during target replication. This finding may have indicated an accuracy cost due to introduced noise when transforming sensory information from a proprioceptive reference frame into a visual reference frame.

Upper Limb Proprioceptive Acuity Assessment Based on Three-Dimensional Position Measurement Systems

The aim of the current work was to verify three-dimensional directional effects on the reproduction error precision of the human upper limb position. Thirty male subjects without history of upper limb pathology were recruited from Renmin University of China. A three-dimensional position reproduction task in six directions (up, down, left, right, far, and near) was performed by each subject. The results suggested that the proprioceptive sense of upper limb position depends on the direction, with smaller absolute errors in Directions 4 (right) and 5 (far) than in Directions 1 (up), 2 (down), 3 (left), and 6 (near). Proprioception near the end of the elbow joint range of motion may be more reliable and sensitive. Subjects reproduced fewer ranges in the horizontal plane (Directions 3, 5, and 6) and they overshot the target position along the z-axis (vertical direction) except for Direction 6. Overestimations of position in the z-axis may be caused by overestimations of force.

Effects of Ving Tsun sticking-hand training on upper-limb sensorimotor performance in community-dwelling middle-aged and older adults: A randomized controlled trial

Objective

To evaluate the effects of Ving Tsun (VT) sticking-hand training on upper-limb joint position sense and muscular performance in community-dwelling middle-aged and older adults.

Methods

Thirty-three adults were randomly allocated to either a VT group or a control group. The VT group received VT sticking-hand training twice per week for 3 months. Measurements were taken before and after the intervention period. The primary outcome was elbow-joint repositioning error, which was measured by an elbow-joint passive positioning and active repositioning test using a universal goniometer. Secondary outcomes were upper-limb muscles’ peak force and time taken to reach peak force as measured by a hand-held dynamometer.

Results

No significant time, group or time-by-group interaction effects were found for elbow-joint repositioning error or upper-limb muscle peak force outcomes. Shoulder flexor time to peak force decreased by 33.8% from pre-test to post-test in the VT group (P = 0.007). Shoulder abductor, internal and external rotator, and elbow extensor times to peak force decreased by 30.0%–35.9% in the VT group (P < 0.05) and by 30.4%–37.1% in the control group (P < 0.05).

Conclusions

VT sticking-hand training does not improve elbow-joint position sense or the maximum strength of upper-limb muscles in middle-aged and older adults. However, VT can improve shoulder flexor muscles’ time to reach peak force in these populations. VT had no obvious effect on the time required to reach peak force in other shoulder muscles and elbow extensors.

Shoulder and elbow joint position sense assessment using a mobile app in subjects with and without shoulder pain - between-days reliability

OBJECTIVES

To determine between-days reliability and the minimal detectable change for shoulder and elbow joint position sense assessment using a validated mobile app, in subjects with and without shoulder pain.

DESIGN

Reliability study.

SETTING

Clinical measurement.

PARTICIPANTS

Subjects with (n = 25) and without shoulder pain (n = 29).

MAIN OUTCOME MEASURES

Subjects were assessed by the same examiner in two sessions, with one-week interval. Active joint repositioning tests of shoulder flexion and scaption and elbow flexion were assessed at the target-angles of 50°, 70°, 90° and 110°. Intra-class correlation coefficient, standard error of measurement and minimal detectable change were calculated for constant, absolute, total and variable errors.

RESULTS

Good to excellent reliability was found for constant, absolute and total errors at the target-angle of 50° of scaption for healthy subjects; at 110° of shoulder flexion and all target-angles for elbow for both groups.

CONCLUSIONS

The mobile app is a reliable tool and may be useful for assessing shoulder joint position sense mainly at 110° of flexion and for elbow between 50° and 110° of flexion in subjects with and without shoulder pain. Minimal detectable changes were demonstrated and may help clinicians to follow-up rehabilitation and researchers to interpret findings of studies.

Gravitational torque partially accounts for proprioceptive acuity

Proprioception of the upper extremity is commonly measured using joint position sense tasks. Recent evidence suggests heightened position sense at elevation angles in the shoulder and elbow near 90° in the sagittal plane. The influence of external torque has been suggested to play a pivotal role in the heightened acuity in elevated positions due to increased moment arm with respect to gravitational vectors. We hypothesized that the addition of a buoyance vector in opposition to this gravitational vector would reduce the influence of torque on proprioceptive acuity, resulting in consistent position sense errors with respect to elevation angle. Joint position sense was measured using an apple iPod touch using a custom application. Participants elevated their arm to 50, 70 and 90° of elevation in the sagittal plane in the absence of visual feedback. Data were collected in three conditions, normal (control) and submerged and weighted. We found angular differences between control and submerged conditions, but not between control and weighted conditions. When the arm was elevated to 90° in the submerged condition, we found participants undershot the target position by approximately -0.5° with the addition of the buoyancy force vector. Participants without this buoyancy vector at the same target position consistently overshot the target by approximately 2.0°, which suggests that external torque may be more involved in the direction of proprioceptive errors more than the magnitude of the error as the magnitude of the difference was relatively small (2.5°).

College Pitchers Demonstrate Directional Differences in Shoulder Joint Position Sense Compared With Controls

CONTEXT

The relationship between overhead throwing and its effect on proprioception is not well understood. It is important to gain a better understanding of how these are related, to protect overhead athletes from an increased risk of injury.

OBJECTIVE

To investigate proprioceptive alterations in the overhead thrower's shoulder.

DESIGN

Cross-sectional study. Independent variables are limb (dominant and nondominant), group (thrower or control), and target angle. Dependent variables are joint position sense and range of motion.

SETTING

An orthopedic biomechanics lab and university athletic training facility.

PARTICIPANTS

Twelve Division I baseball pitchers and 13 nonthrowing control subjects.

INTERVENTION

Shoulder proprioception was assessed using an active joint repositioning task administered with an iPod Touch.

MAIN OUTCOME MEASURE

Root mean square error and constant error of repositioning angles were used to assess accuracy and directional patterns, respectively.

RESULTS

Both groups demonstrated significantly higher joint acuity at the 80° external rotation target angle compared with 60° (1.5° [0.5°], P = .01). There were no differences in accuracy between groups. Constant error revealed differing repositioning patterns between limbs for the pitchers and also between groups for the dominant side. Although the throwing shoulder overshot the target angles by 0.4°, all nonthrowing shoulders undershot by an average of 2.7°.

CONCLUSIONS

There is no difference in shoulder joint position sense accuracy between throwers and nonthrowers, although both groups display increased accuracy closer to their end range of external rotation. The throwing shoulder demonstrates a different repositioning pattern, overshooting the desired target angle, while all other shoulders undershoot.

Patients with type 2 diabetes demonstrate proprioceptive deficit in the knee

AIM

To investigate proprioceptive discrepancies in the lower extremity in persons with type 2 diabetes mellitus (T2DM).

METHODS

In this cross-sectional study, a total of 46 older persons were divided into a T2DM group (n = 23) and a control group who did not have T2DM (n = 23). Participants were given a brief warm up with stretching exercises. Diabetic neuropathy scores were collected prior to proprioceptive testing. For proprioceptive testing, participants performed leg extensions to randomized target positions of 15°, 30°, 45, 60° degrees of elevation in the sagittal plane, each target was repeated a total of four times. Subjects were guided to target positions in the absence of visual feedback via auditory cues from a custom JPS application. When the participant entered the target position, they memorized the location of their limb in space and subsequently attempted to re-locate this position in space. Proprioceptive errors were measured from the target positioned, target remembered, target repositioned protocol.

RESULTS

Proprioceptive accuracy was lower in the diabetic group at all levels of target angle than the control group (P < 0.05). The diabetic group had 46% greater inaccuracy than the control group at all levels of target position. Diabetics also reported greater neuropathy scores than controls in the past 12 mo P < 0.01.

CONCLUSION

Deficits in lower limb localization and greater diabetic neuropathy scores were identified in this study. Our findings may be associated with deafferentation as peripheral neuropathy is a common complication with the disease. These findings may help to explain the declining balance function in the older persons with T2DM which is also commonly reported.

The Influence of External Forces on Wrist Proprioception

Proprioception combines information from cutaneous, joint, tendon, and muscle receptors for maintaining a reliable internal body image. However, it is still a matter of debate, in both neurophysiology and psychology, to what extent such body image is modified or distorted by a changing haptic environment. In particular, what is worth investigating is the contribution of external forces on our perception of body and joint configuration. The proprioceptive acuity of fifteen young participants was tested with a Joint Position Matching (JPM) task, performed with the dominant wrist under five different external forces, in order to understand to what extent they affect proprioceptive acuity. Results show that accuracy and precision in target matching do not change in a significant manner as a function of the loading condition, suggesting that the multi-sensory integration process is indeed capable of discriminating different sub-modalities of proprioception, namely the joint position sense and the sense of force. Furthermore, results indicate a preference for target undershooting when movements are performed in a viscous or high resistive force field, rather than passive or null fields in which subjects did not show any predominance for under/over estimation of their position.

No Relationship Between Joint Position Sense and Force Sense at the Shoulder

In practice, a single test is used to quantify an individual's proprioception. Previous studies have not found a correlation between joint position sense (JPS) and force sense (FS), which are submodalities of proprioception. The purpose of the present study is to determine if root mean square (RMS) error in JPS and FS are related at the shoulder, controlling for external load and elevation angle. Active shoulder angle and force reproduction protocols were performed. No correlation was found between JPS and FS (r = -.019, p = .941) nor were any individual angle and load combinations significant. The main effect for angle in JPS was significant (p < .001). Follow-up contrast demonstrated a significant (p < .001) decrease in RMS error with increased elevation. A significant load by angle interaction was found for FS (p = .014). Follow-up simple effects tests by angle demonstrated RMS error decreased with load at 50° and 70° but not at 90°. By load, RMS error only decreased for 120% between 50° and 90°. JPS and FS demonstrate different behavior with load and angle. This differing behavior is more likely responsible for the lack of correlation than angle and load differences in JPS and FS protocols.

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.

Three-dimensional motion analysis in the elbow joint position sense in children

[Purpose] The purpose of this study was to investigate the difference in elbow joint position sense in children. [Subjects and Methods] Nineteen healthy children volunteered as subjects for this study. Joint position sense was assessed by asking the children to flex their elbows between 30° to 110° while blindfolded. The error range of elbow movement was analyzed with Compact Measuring System 10 for three-dimensional motion. To analyze data, descriptive statistics and paired t-test analysis were performed by using IBM SPSS Statistics 20.0. [Results] A significantly lower error was found in 30° right elbow flexion than 110° right elbow flexion (p<0.05). No significant difference was found between 30° and 110° left elbow flexion. [Conclusion] These results indicate that in children, joint position sense errors decrease as joint angles approach 30° flexion.

Errors in Shoulder Joint Position Sense Mainly Come from the Glenohumeral Joint

While synchronous movement of the glenohumeral and scapulothoracic joints has been emphasized in previous kinematics studies, most investigations of shoulder joint position sense have treated the shoulder complex as a single joint. The purposes of this study were to investigate the joint position sense errors of the humerothoracic, glenohumeral, and scapulothoracic joints at different elevation angles and to examine whether the errors of the glenohumeral and scapulothoracic joints contribute to the errors of the humerothoracic joint. Fifty-one subjects with healthy shoulders were recruited. Active joint position sense of the humerothoracic, glenohumeral, and scapulothoracic joints was measured at 50°, 70°, and 90° of humerothoracic elevation in the scapular plane. The results showed that while scapulothoracic joint position sense errors were not affected by target angles, there was an angle effect on humerothoracic and glenohumeral errors, with errors decreasing as the target angles approached 90° of elevation. The results of a multiple regression analysis revealed that glenohumeral errors explained most of the variance of the humerothoracic errors and that scapulothoracic errors had a weaker predictive relationship with humerothoracic errors. Therefore, it may be necessary to test scapular joint position sense separately in addition to the assessment of the overall shoulder joint position sense.

Robot-Aided Mapping of Wrist Proprioceptive Acuity across a 3D Workspace

Proprioceptive signals from peripheral mechanoreceptors form the basis for bodily perception and are known to be essential for motor control. However we still have an incomplete understanding of how proprioception differs between joints, whether it differs among the various degrees-of-freedom (DoFs) within a particular joint, and how such differences affect motor control and learning. We here introduce a robot-aided method to objectively measure proprioceptive function: specifically, we systematically mapped wrist proprioceptive acuity across the three DoFs of the wrist/hand complex with the aim to characterize the wrist position sense. Thirty healthy young adults performed an ipsilateral active joint position matching task with their dominant wrist using a haptic robotic exoskeleton. Our results indicate that the active wrist position sense acuity is anisotropic across the joint, with the abduction/adduction DoF having the highest acuity (the error of acuity for flexion/extension is 4.64 ± 0.24°; abduction/adduction: 3.68 ± 0.32°; supination/pronation: 5.15 ± 0.37°) and they also revealed that proprioceptive acuity decreases for smaller joint displacements. We believe this knowledge is imperative in a clinical scenario when assessing proprioceptive deficits and for understanding how such sensory deficits relate to observable motor impairments.

Joint position sense - There׳s an app for that

Traditionally, proprioception has been assessed with a passive model, in which an external apparatus moves a body segment. Recently, protocols have been developed based on active movements, which are more representative of functional activities. However, even these approaches require expensive testing equipment and the necessity of a visit to a research lab, as there are no commercially available mobile instruments that allow for the assessment of proprioception outside of a laboratory setting. The objective of this study was to demonstrate the validity and feasibility of using a mobile device (iPod Touch) to assess joint position. We conducted a concurrent validity study in the lab (n=9) and a field based study (n=79). The field based study was conducted at the 2012 American Society of Biomechanics meeting in Gainesville, Florida. The results of both studies demonstrate good agreement with our established protocol using a magnetic tracking device, with angular errors decreasing with increasing shoulder flexion angles. The studies demonstrate the validity and feasibility of using mobile devices for assessing motion-based parameters, both inside and outside of a laboratory setting.

Exercises focusing on rotator cuff and scapular muscles do not improve shoulder joint position sense in healthy subjects

Proprioception is essential for shoulder neuromuscular control and shoulder stability. Exercise of the rotator cuff and scapulothoracic muscles is an important part of shoulder rehabilitation. The purpose of this study was to investigate the effect of rotator cuff and scapulothoracic muscle exercises on shoulder joint position sense. Thirty-six healthy subjects were recruited and randomly assigned into either a control or training group. The subjects in the training group received closed-chain and open-chain exercises focusing on rotator cuff and scapulothoracic muscles for four weeks. Shoulder joint position sense errors in elevation, including the humerothoracic, glenohumeral and scapulothoracic joints, was measured. After four weeks of exercise training, strength increased overall in the training group, which demonstrated the effect of exercise on the muscular system. However, the changes in shoulder joint position sense errors in any individual joint of the subjects in the training group were not different from those of the control subjects. Therefore, exercises specifically targeting individual muscles with low intensity may not be sufficient to improve shoulder joint position sense in healthy subjects. Future work is needed to further investigate which types of exercise are more effective in improving joint position sense, and the mechanisms associated with those changes.

Motor Control Performance During Rapid Voluntary Movements of Elbow and Knee

Knowledge of motor control differences during rapid goal-directed movements of the upper and lower limbs could be useful in improving rehabilitation protocols. The authors investigated performance and control differences between elbow and knee joints and between different contraction types (concentric vs. eccentric) during rapid movements under externally applied load. There were no significant differences in performance and control with respect to joint (elbow vs. knee) but the performance during concentric contractions was better than eccentric for both the joints. The findings indicate that despite anatomical and functional differences, the CNS is finely tuned for both the joints to maximize the efficiency of movement during a dynamic environment, but there are differences in control strategies between the 2 contraction types.

Kinesio taping of the deltoid does not reduce fatigue induced deficits in shoulder joint position sense

BACKGROUND

Muscle fatigue is known to decrease shoulder proprioceptive acuity, potentially contributing to injuries. It has been suggested that Kinesio taping can improve proprioception. Therefore, the aim of this study was to investigate the effects of Kinesio taping on shoulder joint position sense after muscle fatigue.

METHODS

Twenty-four healthy subjects were evaluated in a randomized, crossover, single-blind study design. Shoulder joint position sense was assessed during active repositioning tests at the target angles of 50°, 70° and 90° of arm elevation in scapular plane, in three sessions: control (no taping), Kinesio taping (Kinesio taping applied over the deltoid muscle with tension) and sham (Kinesio taping applied over deltoid without tension). Joint position sense was assessed three times: before taping; following taping application or rest, in the control session; and following a fatigue protocol. The constant error (repositioned angle-target angle) was considered for statistical analysis, using a 3-way repeated-measure ANOVA (within subject factors: taping, time and target angle).

FINDINGS

There was no interaction or main effect involving taping. An interaction between time and angle was found and the simple effect showed that the constant error increased following fatigue at 70° and 90°, but not at 50°.

INTERPRETATION

The results of this study does not support the use of Kinesio taping applied over the deltoid muscle for compensating or preventing shoulder joint position sense deficits caused by muscle fatigue of shoulder abductors.

The effects of shoulder injury on kinaesthesia: a systematic review and meta-analysis

The aim of this systematic review was to synthesize the evidence for changes for proprioceptive variables consisting of movement and position sense in participants with glenohumeral musculoskeletal disorders. Five databases were searched until 13th August 2013. Methodological quality was assessed and meta-analyses were performed for active and passive joint reposition sense (AJPS and PJPS) and movement sense, determined with threshold to detection of passive motion (TTDPM). The search yielded 17 studies, four of which were classified as having high methodological quality, seven as moderate and six as low quality. For participants with post-traumatic glenohumeral instability, pooled findings indicate moderate evidence for higher TTDPM for involved shoulders compared to control groups and the contralateral uninvolved side, indicating decreased movement sense. For AJPS and PJPS there was moderate to limited evidence for significant increased errors for involved compared to uninvovled shoulders, but not when compared to the control groups. Limited evidence was found for decreased AJPS acuity for patients with chronic rotator cuff pain and for patients with unspecified shoulder pain compared to healthy controls. Movement sense is most likely to be impaired after shoulder injury involving post-traumatic instability when compared to the contralateral shoulder and to controls, while deficits for AJPS and PJPS are more likely to be evident compared to the contralateral shoulder in participants with glenohumeral musculoskeletal disorders.

Joint position sense during a reaching task improves at targets located closer to the head but is unaffected by instruction

The purpose of the present study was twofold. Our first purpose was to test whether joint position sense is similar under instructions to memorize hand position and instructions to memorize shoulder and elbow angles. We hypothesized that instructions to memorize hand position would produce smaller errors due to evidence suggesting that the CNS directly determines hand position but indirectly determines joint angles from proprioceptive information. Our second purpose was to assess biases in joint position sense at various joint angles in a sagittal workspace. We hypothesized that akin to previous single-joint investigations, the shoulder and elbow would demonstrate better joint position sense as joint angles approached 90° during our multi-joint task. Sixteen healthy and right-hand-dominant subjects participated in the present investigation. Subjects were required to actively position their right upper extremity to one of three targets for a memorization period. After returning to the rest position, subjects then actively repositioned back into the target. We did not find evidence of a substantial difference in joint position sense between instructions to memorize the hand position or joint angle. This finding, when considered in conjunction with other evidence, suggests that studies employing either a joint angle protocol or a hand estimation protocol likely produce results that are similar enough to be compared. Proprioception has been shown to be non-uniform across a two-dimensional horizontal workspace. The present investigation provides evidence that proprioception is also non-uniform across a two-dimensional sagittal workspace. Specifically, angular errors decrease as upper extremity joint angles approach 90° of flexion and endpoint errors decrease as targets are located increasingly closer to the head.