The impact of rotator cuff tendinopathy on proprioception, measuring force sensation

Shoulder proprioception changes in postmastectomy patients: an observational study

PURPOSE

Breast cancer surgery can cause changes in the anatomical structure of the shoulder and in shoulder mobility, leading to the increased possibility of long-term arm morbidity such as lymphedema. This study aims to evaluate the active shoulder joint position sense (AJPS) with and without lymphedema in postmastectomy patients.

METHODS

A total of 66 women, including 22 patients with lymphedema, 22 patients without lymphedema, and 22 healthy controls, were enrolled in the study. Pain severity was evaluated with the Numeric Pain Scale and edema severity was measured with circumferentially at 10 cm intervals. The normal range of motion of the shoulder joint was evaluated with the universal goniometer and the AJPS was assessed by active position repetition testing at 55°, 90°, and 125° shoulder flexion targets using the smartphone application "Clinometer."

RESULTS

AJPS at 55°, 90°, and 125° shoulder flexion target angles with and without lymphedema were different in all target angles compared to healthy controls (p < 0.01). There was a difference between the absolute error value of AJPS at 55° flexion (p < 0.05), and no difference at 90° and 125° flexion between the with and without lymphedema groups (p > 0.05).

CONCLUSION

This study shows that the AJPS was negatively affected in with and without lymphedema postmastectomy patients compared to healthy controls. This result emphasizes the importance of adding personalized methods for the restoration of joint position sense in addition to rehabilitation programs generally applied to the patient group.

Shoulder Proprioception: A Review

The purpose of this review is to provide a comprehensive resource for shoulder proprioception assessment and its integration into clinical decision making as well as targeted rehabilitation protocols. Data for this review were acquired from peer-reviewed articles from computerized online databases, namely PubMed and Medline, published between 1906 and 2021. The development of digital/smart phone goniometers can improve shoulder joint range of motion (ROM) measurements and demonstrate comparable measurement accuracy to the universal standard goniometer. The inclinometer offers a portable and cost-effective method for measuring shoulder joint angles and arcs of motion in the vertical plane. Two types of dynamometers, the computerized isokinetic machine and the handheld hydraulic dynamometer, are reliable tools for objective shoulder rotator cuff strength assessment. Motion analysis systems are highly advanced modalities that create three-dimensional models of motion arcs using a series of cameras and reflective beads, offering unparalleled precision in shoulder proprioception measurement; however, they require time-consuming calibration and skilled operators. Advancements in wearable devices and compact mobile technology such as iPhone applications may make three-dimensional motion analysis more affordable and practical for outpatient settings in the future. The complex interplay between proprioception and shoulder dysfunction is not fully understood; however, shoulder proprioception can likely both contribute to and be caused by shoulder pathology. In patients with rotator cuff tears, glenohumeral osteoarthritis, and shoulder instability, clinicians can track proprioception to understand a patient's disease progression or response to treatment. Finally, rehabilitation programs targeting shoulder proprioception have shown promising initial results in restoring function and returning athletes to play.

Reduced shoulder proprioception due to fatigue after repeated handball throws and evaluation of test-retest reliability of a clinical shoulder joint position test

Background

Proprioception is vital for motor control and can be disturbed, for example, due to fatigue or injury. Clinical feasible, reliable and valid tests of shoulder proprioception are warranted. The aim was to investigate the effects of local fatigue on shoulder proprioception and the reliability of a feasible joint position sense test using an experimental repeated measures design.

Method

Forty participants repeated a shoulder joint position sense test to assess test-retest reliability. The test was then utilized on a subgroup of handball players who were subjected to five bouts of a repeated throwing task with the dominant hand. The effect of local fatigue was investigated by comparing the fatigued with the non-fatigued shoulder.

Results

There was a significant interaction for the arm × bout (p = 0.028, ηp2 = 0.20) and a significant effect for the arm (p = 0.034, ηp2 = 0.35) with a significant decrease in joint position sense for the throwing arm compared to the non-throwing arm. The intraclass correlation coefficient was 0.78 (95% CI = [0.57; 0.89]). The standard error of measurement between trials was 0.70° (range: 0.57°-0.90°).

Discussion

The results indicate that repeated throwing to fatigue disturbs shoulder joint position sense. Assessment with the modified test showed acceptable reliability and can be a valuable assessment tool in the clinic.

Effects of Presence Rate of the Palmaris Longus Tendon on Wrist Proprioception and Grip Strength

INTRODUCTION

The palmaris longus muscle displays a great variation in terms of incidence and shape. This study has documented the incidence ratio of this muscle among the students at Bolu Abant İzzet Baysal University, Faculty of Medicine, and has revealed the effects of its presence on wrist proprioception and grip strength.

METHODS

A total of 101 students between the ages of 18 and 25 were included in the study. Age, height, weight, body mass index (BMI), and dominant upper extremity of the individuals were recorded. After the presence of palmaris longus tendon (PLT) was determined by using the Schaeffer's test, wrist proprioception was evaluated by using a digital inclinometer, and grip strength was evaluated by using a hand dynamometer.

RESULTS

PLT absence rates were evaluated separately as right and left, and it was found as 16.8% and 17.8%. No correlation was found between the dominant upper extremity and BMI and the presence of PLT. The presence or absence of PLT has no effect on grip strength and wrist proprioception.  Conclusion: PLT is used in many clinical areas, such as reconstructive and cosmetic surgery, graft applications, tendon repairs, ptosis correction operations, and ligament stabilization. We think there will be no significant loss in the sense of proprioception and grip strength in the absence of PLT.

Assessment of grip force sense test-retest reliability in healthy male participants

There has been a lack of research to date regarding the test-retest reliability of grip force sense in healthy adult males. This study was therefore designed to explore this topic across a series of target force levels using an ipsilateral force reproduction task. The same experienced research staff conducted two testing sessions for each study participant, with 1 week between test sessions. Intraclass correlation coefficient values indicated that these force sensing tests exhibited good to fair reliability with respect to both absolute error (0.42-0.63) and constant error (0.49-0.60), although variable error was indicative of poor reliability (-0.85 to 0.14). Together, these results suggest that researchers can achieve a fair level of test-retest reliability when analysing grip force sense in healthy adult males, with results being most reliable at force levels of 20 N and 50 N, as determined based upon measured constant error and absolute error. Practitioner summary: To ensure that grip force sense can be accurately interpreted over time, it is important to assess the test-retest reliability. It is recommended that practitioners measure the absolute error and constant error at force levels of 20 N and 50 N when assessing grip force sense in a clinical setting.

People with chronic low back pain display spatial alterations in high-density surface EMG-torque oscillations

We quantified the relationship between spatial oscillations in surface electromyographic (sEMG) activity and trunk-extension torque in individuals with and without chronic low back pain (CLBP), during two submaximal isometric lumbar extension tasks at 20% and 50% of their maximal voluntary torque. High-density sEMG (HDsEMG) signals were recorded from the lumbar erector spinae (ES) with a 64-electrode grid, and torque signals were recorded with an isokinetic dynamometer. Coherence and cross-correlation analyses were applied between the filtered interference HDsEMG and torque signals for each submaximal contraction. Principal component analysis was used to reduce dimensionality of HDsEMG data and improve the HDsEMG-based torque estimation. sEMG-torque coherence was quantified in the δ(0–5 Hz) frequency bandwidth. Regional differences in sEMG-torque coherence were also evaluated by creating topographical coherence maps. sEMG-torque coherence in the δ band and sEMG-torque cross-correlation increased with the increase in torque in the controls but not in the CLBP group (p = 0.018, p = 0.030 respectively). As torque increased, the CLBP group increased sEMG-torque coherence in more cranial ES regions, while the opposite was observed for the controls (p = 0.043). Individuals with CLBP show reductions in sEMG-torque relationships possibly due to the use of compensatory strategies and regional adjustments of ES-sEMG oscillatory activity.

Exploring Sex Differences and Force Level Effects on Grip Force Perception in Healthy Adults

This study aimed to explore the effect of sex and force level on grip force reproduction in healthy adults by conducting a force reproduction task. Participants (n = 28) were instructed to replicate a range of reference grip force levels (10-130 N in 10 N increments). We found that women (absolute error: 16.2 ± 8.7 N) replicated these force levels more accurately than men (absolute error: 23.1 ± 9.5 N) at higher force levels (90-130 N). Furthermore, the force reproductions were most accurate at the 30-50 N range for men and the 50-60 N range for women. These results may offer significant insights into the higher rates of musculoskeletal disorders among women, enabling researchers and clinicians to design novel interventions and tools that can improve grip force perception and reduce hand injury rates in both men and women.

Inter-Limb Asymmetry in Force Accuracy and Steadiness Changes after a 12-Week Strength Training Program in Young Healthy Men

The study aimed to investigate the impact of a 12-week strength training program on force accuracy and steadiness changes in lower limbs in young healthy men. Twenty subjects with a dominant right lower limb were included. They performed a force matching task both pre and post strength training program. The ability to reproduce force was determined by calculating three errors: absolute error (AE), constant error (CE), and variable error (VE). After intervention AE and VE improved in both legs indicating higher improvement in the dominant leg (p = 0.032 for AE and p = 0.005 for VE). However, CE improved only in the dominant leg (p = 0.001). We conclude that strength training improved the accuracy and consistency of force in a force reproduction task. This improvement was more evident in the dominant lower limb. Most likely, the inter-limb asymmetry in changes of force application ability caused by strength training is due to the different mechanisms responsible for the control of voluntary movements in the dominant and non-dominant lower limb.

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.

Upper limb active joint repositioning during a multijoint task in participants with and without rotator cuff tendinopathy and effect of a rehabilitation program

STUDY DESIGN

Cross-sectional and longitudinal (exploratory) studies.

INTRODUCTION

Rotator cuff (RC) tendinopathy is the most prevalent shoulder diagnosis, and proprioception deficits are often observed in individuals with RC tendinopathy.

PURPOSE OF THE STUDY

This study aimed to evaluate upper limb proprioception during a multijoint task in participants with and without RC tendinopathy and to determine if symptoms, functional limitations, and proprioception are improved after a rehabilitation program.

METHODS

Twenty participants with and 20 without RC tendinopathy were recruited for the cross-sectional study, and 23 participants with RC tendinopathy were recruited for the longitudinal study. Proprioception was evaluated by an active joint-repositioning task: The upper limb was passively moved to a predetermined position, and the participant was asked to actively replicate the movement. The difference between the predetermined position and the replicated position was measured. The mean errors in positions of lateral, medial, and neutral rotation of the shoulder and the global mean error were reported. In addition to the active-repositioning assessment in the longitudinal study, symptoms and functional limitations were evaluated by the Disability of the Arm Shoulder and Hand questionnaire.

RESULTS

Significant deficits in active repositioning (p < .01), independent of the position, were observed in participants with RC tendinopathy compared with controls. The DASH score was improved after rehabilitation intervention (p < .001), and patients with active-repositioning deficits at baseline had reduced repositioning error (p < .05).

CONCLUSIONS

Upper limb active joint repositioning was impaired in participants with RC tendinopathy. Symptoms and functional limitations and active joint repositioning in participants with RC tendinopathy and initial deficits were improved after a 6-week global rehabilitation program.

Does pain influence force steadiness? A protocol for a systematic review

INTRODUCTION

Performing contractions with minimum force fluctuations is essential for everyday life as reduced force steadiness impacts on the precision of voluntary movements and functional ability. Several studies have investigated the effect of experimental or clinical musculoskeletal pain on force steadiness but with conflicting findings. The aim of this systematic review is to summarise the current literature to determine whether pain, whether it be clinical or experimental, influences force steadiness.

METHODS AND ANALYSIS

This protocol for a systematic review was informed and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and the Cochrane Handbook for Systematic Reviews of Interventions. Key databases will be searched from inception to 31 August 2020, including MEDLINE, EMBASE, PubMed, CINAHL Plus, ZETOC and Web of Science. Grey literature and key journals will be also reviewed. Risk of bias will be assessed with the Newcastle-Ottawa tool, and the quality of the cumulative evidence assessed with the Grading of Recommendations, Assessment, Development and Evaluation guidelines. If homogeneity exists between groups of studies, meta-analysis will be conducted. Otherwise, a narrative synthesis approach and a vote-counting method will be used, while the results will be presented as net increases or decreases of force steadiness.

ETHICS AND DISSEMINATION

The findings will be presented at conferences and the review will be also submitted for publication in a refereed journal. No ethical approval was required.

PROSPERO REGISTRATION NUMBER

CRD42020196479.

Sensory Processing in People With and Without Tendinopathy: A Systematic Review With Meta-analysis of Local, Regional, and Remote Sites in Upper- and Lower-Limb Conditions

OBJECTIVE

To synthesize results of somatosensory processing tests in people with upper- and lower-limb tendinopathy, compared to controls.

DESIGN

Systematic review with meta-analysis.

LITERATURE SEARCH

Four electronic databases (MEDLINE, CINAHL Plus, SPORTDiscus, and Embase) were searched.

STUDY SELECTION CRITERIA

Included studies measured a domain of sensory processing and compared a tendinopathy group to a healthy control group.

DATA SYNTHESIS

Meta-analysis was conducted for outcomes with homogeneous data from at least 2 studies. Upper- and lower-limb conditions were compared and outcomes were examined by measurement site (local, regional, or remote to location of pain).

RESULTS

Of the 30 studies included, 18 investigated lateral elbow tendinopathy. The most commonly assessed outcome measures were pressure pain threshold (PPT) and thermal pain threshold. There was moderate evidence for local and regional reduction of PPT in upper-limb tendinopathies, but not at remote sites. In lower-limb tendinopathies, there was conflicting evidence regarding reduced PPT at local sites and limited evidence of normal PPT at remote sites. There was moderate evidence of sensitization of thermal pain threshold at local sites in upper-limb tendinopathies and limited evidence of no difference in thermal pain threshold in lower-limb tendinopathies. Findings across other domains were variable.

CONCLUSION

Sensory processing was different between upper-limb tendinopathy and lower-limb tendinopathy. Upper-limb tendinopathies showed signs consistent with primary and secondary hyperalgesia, but lower-limb tendinopathies did not. There was mixed evidence for primary hyperalgesia and limited evidence against secondary hyperalgesia. J Orthop Sports Phys Ther 2021;51(1):12-26. doi:10.2519/jospt.2021.9417.

Reduced force entropy in subacromial pain syndrome: A cross-sectional analysis

BACKGROUND

Generating a force at the hand requires moments about multiple joints by a theoretically infinite number of arm and shoulder muscle force combinations. This allows for learning and adaptation and can possibly be captured using the complexity (entropy) of an isometrically generated force curve. Patients with Subacromial Pain Syndrome have difficulty to explore alternative, pain-avoiding, motor strategies and we questioned whether loss of motor complexity may contribute to this. We assessed whether patients with Subacromial Pain Syndrome have reduced entropy of an isometrically generated abduction and adduction force curve.

METHODS

Forty patients and thirty controls generated submaximal isometric ab- and adduction force at the wrist. The force curve was characterized by the magnitude of force variability [standard deviation and coefficient of variation], and the entropy (complexity) of force variability [approximate entropy].

FINDINGS

Patients showed reduced entropy both during the abduction (-0.16, confidence interval: [-0.33; -0.00], p: 0.048) and adduction task (-0.20, confidence interval: [-0.37; -0.03], p: 0.024) and reduced force variability during abduction (standard deviation: -0.006, confidence interval: [-0.011; -0.001], p: 0.013 and coefficient of variation: -0.51, confidence interval: [-0.93; -0. 10], p: 0.016).

INTERPRETATIONS

Isometric force curves of patients with Subacromial Pain Syndrome show reduced complexity compared to asymptomatic controls, which may indicate more narrow and stereotype use of motor options. In future studies, it should be investigated whether the finding of reduced force (motor) entropy indicates functional decline, contributing to decreased ability to acquire and optimize motor strategies in Subacromial Pain Syndrome.

LEVEL OF EVIDENCE

Level II prognostic study.

Can a Conservative Rehabilitation Strategy Improve Shoulder Proprioception? A Systematic Review

CONTEXT

Proprioception deficits contribute to persistent and recurring physical disability, particularly with shoulder disorders. Proprioceptive training is thus prescribed in clinical practice. It is unclear whether nonsurgical rehabilitation can optimize shoulder proprioception.

OBJECTIVES

To summarize the available evidence of conservative rehabilitation (ie, nonsurgical) on proprioception among individuals with shoulder disorders.

EVIDENCE ACQUISITION

PubMed, Web of Science, and EBSCO were systematically searched, from inception until November 24, 2019. Selected articles were systematically assessed, and the methodological quality was established using the Dutch Cochrane Risk of Bias Tool and the Newcastle-Ottawa Quality Assessment Scale. The Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were utilized for this review. The conservative treatments were categorized as follows: (1) conventional therapy, (2) proprioceptive training, (3) elastic kinesiology tape, and (4) other passive therapies.

EVIDENCE SYNTHESIS

Twelve articles were included, yielding 58 healthy control shoulders and 362 shoulders affected by impingement syndrome, glenohumeral dislocations, nonspecific shoulder pain, rotator cuff dysfunction, or subluxation poststroke. The level of agreement between the evaluators was excellent (84.9%), and the studies were evaluated to be of fair to excellent quality (risk of bias: 28.5%-100%). This review suggests, with moderate evidence, that proprioceptive training (upper-body wobble board or flexible foil training) can improve proprioception in the midterm. No decisive evidence exists to suggest that conventional therapy is of added value to enhance shoulder proprioception. Conflicting evidence was found for the improvement of proprioception with the application of elastic kinesiology tape, while moderate evidence suggests that passive modalities, such as microcurrent electrical stimulation and bracing, are not effective for proprioceptive rehabilitation of the shoulder.

CONCLUSIONS

Proprioceptive training demonstrates the strongest evidence for the effective rehabilitation of individuals with a shoulder proprioceptive deficit. Elastic kinesiology tape does not appear to affect the sense of shoulder proprioception. This review suggests a possible specificity of training effect with shoulder proprioception.

Dynamic scapular recognition exercise improves scapular upward rotation and shoulder pain and disability in patients with adhesive capsulitis: a randomized controlled trial

BACKGROUND

Examine the ability of a dynamic scapular recognition exercise to improve scapular upward rotation and decrease shoulder pain and disability in patients with adhesive capsulitis of the shoulder.

METHODS

A test-retest randomized controlled study design was used. A total of sixty-six patients with unilateral adhesive capsulitis were equally divided into two groups. The study group received a dynamic scapular recognition exercise using a wireless biofeedback system, while the control group received placebo treatment in the form of active range-of-motion (ROM) exercises of the sound upper limb. A digital inclinometer was used to measure the scapular upward rotation and ROM of the shoulder joint, and the Shoulder Pain and Disability Index (SPADI) was used to measure the shoulder pain and disability.

RESULTS

Study results showed that after two weeks, there were statistically significant differences between the study and control groups in scapular upward rotation and shoulder flexion and abduction (P < .05) and nonsignificant differences in shoulder external rotation and SPADI (P > .05). After two and six months, there were statistically significant differences between study and control groups in scapular upward rotation; shoulder flexion, abduction and external rotation; and SPADI scores (P < .05).

CONCLUSION

This study showed that a dynamic scapular recognition exercise significantly improves scapular upward rotation and the ROM of shoulder flexion and abduction after two weeks. At two and six months, this exercise improves scapular upward rotation; ROM of shoulder flexion, abduction, and external rotation; and SPADI scores. These improvements persisted for six months after the performance of this exercise.

Effect of Force Level and Gender on Pinch Force Perception in Healthy Adults

This study investigated the effects of both force level and gender on pinch force reproduction errors in normal participants during an ipsilateral force reproduction task. In total, 20 healthy participants were asked to generate a range of levels of reference forces ranging from 5% to 60% maximal voluntary isometric contraction (MVIC) in increments of 5% MVIC using the tip pinch and to reproduce these forces using the same hand. The results showed that the males more accurately and consistently reproduced the forces than did the females, and the most accurate estimation occurred at approximately 20% to 35% MVIC. This finding can help us better understand the reasons for the higher rate of musculoskeletal disorders in females than in males and to develop tools and preventive strategies to decrease the rate of hand injuries in both genders.

Test-retest reliability of tip, key, and palmar pinch force sense in healthy adults

Background

No previous studies have investigated the test–retest reliability of tip, key, and palmar pinch force sense in healthy adults. The present study explores the test-retest reliability of tip, key, and palmar pinch force sense for different force levels in healthy adults during an ipsilateral force reproduction task.

Methods

Fifty-six healthy subjects were instructed to produce varying levels of reference forces (10, 30, and 50% maximal voluntary isometric contraction (MVIC)) using three types of pinches (tip pinch, palmar pinch, and key pinch) and to reproduce these forces using the same hand. The subjects were tested twice by the same experienced testers, 1 week apart.

Results

Based on the high values of the intraclass correlation coefficient (ICC), the tip pinch (0.783–0.895) and palmar pinch (0.752–0.903) force sense tests demonstrated good reliability for all the variables. The ICCs for the key pinch (0.712–0.881) indicated fair to good relative test-retest reliability.

Conclusion

1) This study demonstrates that high test-retest reliability of tip, key, and palmar pinch force sense in healthy adults can be achieved using standardized positioning and the proposed approach. 2) According to the reliability measurements, 30 and 50% maximal voluntary isometric contraction (MVIC) are the most reliable pinch force sense levels.

Laser testing for upper extremity proprioceptive deficits following rotator cuff injury: two case reports

Background: Rotator cuff (RTC) dysfunction incidence ranges from 7% to 25% in the general population with a high recurrence rate. RTC musculature plays a significant role in dynamic stability of the glenohumeral joint with damage to these structures associated with proprioceptive impairments. Impaired proprioception has been linked to increased injury risk in other body regions; however, similar relationships with the upper extremity have not been extensively evaluated. The purpose of this case report is to present a preliminary, yet clinically feasible approach for using a laser for proprioceptive assessment and treatment in patients with RTC dysfunction. Case description: Patient 1 was a 21-year-old female with right shoulder pain from injury at work as a waitress where she lifted a heavy tray of plates. Patient 2 was a 48-year-old male with gradual and insidious onset of right shoulder pain during recreational baseball. Examination findings indicated contractile tissue involvement in both patients. Reaching and throwing tasks requiring accurate proprioceptive function were essential for return of each patient to their functional tasks. Laser proprioception testing was performed every 2 weeks with proprioceptive training provided as a supplement to other interventions. Outcomes: Over 4 weeks, improvements in objective laser proprioceptive test results were observed for both patients (Patient 1 = 6.0 cm; Patient 2 = 5.5 cm) in conjunction with active range-of-motion and self-report measures for pain intensity and function. Discussion: This case report describes a clinically feasible approach to testing and treating upper extremity proprioceptive deficits after RTC injury. Future research is required to establish reliability and validity of these methods.

Shoulder proprioception in patients with subacromial impingement syndrome

BACKGROUND

Recently, proprioception deficits of the rotator cuff and the deltoid muscles have been suggested to play a pivotal role in the subacromial impingement syndrome (SIS). To date, there are no study has been found where the kinesthesia and joint position senses have been evaluated together in SIS.

OBJECTIVE

To investigate the shoulder proprioception in patients with SIS.

METHODS

Sixty-one patients with SIS and 30 healthy controls, aging between 25 and 65 years, were included in the study. Main outcome measure was proprioception, assessed with an isokinetic dynamometer. Kinesthesia, active and passive joint repositioning senses were tested at 0° and 10° external rotation. All tests were repeated 4 times and the mean of angular errors were obtained.

RESULTS

The mean age was 49.14 ± 10.27 and 48.80 ± 11.09 years in patient group and in control group respectively. No significant difference was found between two groups in terms of age, gender and dominance. When involved and uninvolved shoulders of the patient group were compared, kinesthesia, active and passive joint position senses were significantly impaired in involved shoulders at all angles (P < 0.05). When involved shoulders of the patient group were compared to the control group, kinesthesia, active and passive joint position senses were significantly impaired in involved shoulders in patient group at all angles (P < 0.05) except active position sense at 0°. When uninvolved shoulders of the patient group were compared to the control group, kinesthesia at 10° was significantly impaired (P < 0.05).

CONCLUSION

This study showed that shoulder proprioception was impaired in patients with SIS. This proprioceptive impairment was found not only in involved shoulders but also in uninvolved shoulders in patients with SIS.

Relationship between Joint Position Sense, Force Sense, and Muscle Strength and the Impact of Gymnastic Training on Proprioception

The aims of this study were (1) to assess the relationship between joint position (JPS) and force sense (FS) and muscle strength (MS) and (2) to evaluate the impact of long-term gymnastic training on particular proprioception aspects and their correlations. 17 elite adult gymnasts and 24 untrained, matched controls performed an active reproduction (AR) and passive reproduction (PR) task and a force reproduction (FR) task at the elbow joint. Intergroup differences and the relationship between JPS, FS, and MS were evaluated. While there was no difference in AR or PR between groups, absolute error in the control group was higher during the PR task (7.15 ± 2.72°) than during the AR task (3.1 ± 1.93°). Mean relative error in the control group was 61% higher in the elbow extensors than in the elbow flexors during 50% FR, while the gymnast group had similar results in both reciprocal muscles. There was no linear correlation between JPS and FS in either group; however, FR was negatively correlated with antagonist MS. In conclusion, this study found no evidence for a relationship between the accuracy of FS and JPS at the elbow joint. Long-term gymnastic training improves the JPS and FS of the elbow extensors.

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.

Impact of Patellar Tendinopathy on Knee Proprioception: A Cross-Sectional Study

OBJECTIVE

To determine whether high-level athletes with patellar tendinopathy have diminished knee proprioceptive acuity.

DESIGN

Cross-sectional study.

SETTING

University research laboratory (institutional).

PARTICIPANTS

Twenty-one basketball and volleyball players with patellar tendinopathy (13 men and 8 women; mean age 24.5 ± 3.6; body mass index = 22.5 ± 2.0 kg/m) and an equal number of athletes without symptoms of patellar tendinopathy injury were included in this study.

ASSESSMENTS

Participants underwent knee proprioception assessments on a single day. Furthermore, age, sex, height, weight, VISA-P (Victorian Institute of Sport Assessment) questionnaire sports participation, medical history, knee injuries, previous treatment, and medication were obtained.

MAIN OUTCOME MEASURES

Knee proprioception was evaluated by assessing sense of resistance, using a weight discrimination protocol, and joint position sense (JPS).

RESULTS

No significant differences were observed in JPS at 30 and 60 degrees of knee flexion between groups (P = 0.165 and 0.481, respectively). In regard to the ability to discriminate weight, significant differences between the 2 groups were found with the tendinopathy group showing a higher percentage of error (P = 0.009), namely when the set of incremental weights varied by 10% from the standard weight.

CONCLUSIONS

Athletes with patellar tendinopathy have a diminished perception of force signals required for weight discrimination, whereas JPS remains unaffected in these athletes.

Shoulder proprioception - lessons we learned from idiopathic frozen shoulder

Background

Of all the most frequent soft tissue disorders of the shoulder, idiopathic frozen shoulder (IFS) offers the greatest potential for studying proprioception. Studies concerning the presence of proprioception dysfunctions have failed to determine the potential for spontaneous healing of passive shoulder stabilizers (anterior and posterior capsule, middle and inferior gleno-humeral ligaments), its relationship with passive (PJPS) and active (AJPS) shoulder proprioception for internal and external rotation (IR, ER), as well as the isokinetic muscle performance of the internal and external rotators. This study investigates these dependencies in the case of arthroscopic release of IFS.

Methods

The study group comprised 23 patients (average aged 54.2) who underwent arthroscopic release due to IFS and 20 healthy volunteers. The average follow-up time was 29.2 months. The Biodex system was used for proprioception measurement in a modified neutral arm position and isokinetic evaluation. The results were analysed using the T-test, Wilcoxon and interclass correlation coefficient. P-values lower than 0.05 were considered significant.

Results

Statistically significant differences were found between involved (I) and uninvolved (U) shoulders only in the cases of PJPS and AJPS, peak torque, time to peak torque and acceleration time for ER (p < 0.05). No statistically significant difference was noted between PJPS IR and PJPS ER or between AJPS IR and AJPS ER (p > 0.05) for the U shoulders.

Conclusions

The anatomical structure of anterior (capsule, middle and anterior band of inferior gleno-humeral ligament) and posterior (capsule and posterior band of inferior gleno-humeral ligament) passive shoulder restraints has no impact on the difference in PJPS values between ER and IR in a modified neutral shoulder position. The potential for spontaneous healing of the anterior and posterior passive shoulder restraints influences PJPS recovery after arthroscopic release of IFS. ER peak torque deficits negatively affect AJPS values. PJPS and AJPS of ER and IR can be measured with a high level of reproducibility using an isokinetic dynamometer with the arm in a modified neutral shoulder position. Differences greater than 15 % for PJPS and >24 % for AJPS for ER and IR can be helpful for future studies as baseline data for identification of particular passive and active shoulder stabilizers at risk.

Correlation study of knee joint proprioception test results using common test methods

[Purpose] To study the correlation of the results obtained from different proprioception test methods, namely, the joint angle reset method, the motion minimum threshold measurement method, and the force sense reproduction method, performed on the same subjects' knees. [Subjects and Methods] Different proprioception test methods, the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method were used to test the knees of 30 healthy young men. [Results] Correlations were found in the following descending order from strong to weak: the correlation between the joint angle reset method and the force sense reproduction method (correlation coefficient of 0.41), the correlation between the joint angle reset method and the motion minimum threshold measurement method (correlation coefficient of 0.29), the correlation between the motion minimum threshold measurement method and the force sense reproduce method (correlation coefficient of 0.15). [Conclusion] No correlation was found among the results obtained using the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method. Therefore, no correlation was found among the position sense, the motion sense and the force sense represented by these methods. Using the results of only one of the test methods to represent proprioception is one-sided. Force sensation depends more on the sensory input of information from the Golgi tendon organs, motion sense depends more on the input information of the muscle spindles, and position sense relies on the double input information of the muscle spindles and the Golgi tendon organs.

The role of the peripheral and central nervous systems in rotator cuff disease

Rotator cuff (RC) disease is an extremely common condition associated with shoulder pain, reduced functional capacities, and impaired quality of life. It primarily involves alterations in tendon health and mechanical properties that can ultimately lead to tendon failure. RC tendon tears induce progressive muscle changes that have a negative impact on surgical reparability of the RC tendons and clinical outcomes. At the same time, a significant base of clinical data suggests a relatively weak relationship between RC integrity and clinical presentation, emphasizing the multifactorial aspects of RC disease. This review aims to summarize the potential contribution of peripheral, spinal, and supraspinal neural factors that may (1) exacerbate structural and functional muscle changes induced by tendon tear, (2) compromise the reversal of these changes during surgery and rehabilitation, (3) contribute to pain generation and persistence of pain, (4) impair shoulder function through reduced proprioception, kinematics, and muscle recruitment, and (5) help explain interindividual differences and response to treatment. Given the current clinical and scientific interest in peripheral nerve injury in the context of RC disease and surgery, we carefully reviewed this body of literature with a particular emphasis on suprascapular neuropathy that has generated a large number of studies in the past decade. Within this process, we highlight the gaps in current knowledge and suggest research avenues for scientists and clinicians.