Joint Position Sense Measurements Research Articles

Balance Control Deficits are Associated With Diminished Ankle Force Sense, Not Position Sense, in Athletes with Chronic Ankle Instability

ObjectivesTo compare balance control and ankle proprioception between athletes with and without chronic ankle instability (CAI). A further objective was to explore the relationship between balance control performance and ankle proprioception in athletes with CAI. DesignCross-sectional study. SettingsSports Rehabilitation Laboratory. ParticipantsEighty-eight recreational athletes (47 CAI and 41 healthy control) were recruited. InterventionsNo applicable. Main Outcome MeasuresBalance control performance was assessed using the sway velocity of the center of the pressure during the one-leg standing tasks. Ankle proprioception, including joint position sense and force sense, were tested using absolute error (AE) associated with joint position reproduction and force reproduction tasks in 4 directions, that is, plantarflexion, dorsiflexion, inversion, and eversion. ResultsAthletes with CAI performed significantly worse than those without CAI in balance control tasks. In addition, CAI athletes showed significantly worse joint position sense and force sense in all 3 movement directions tested (plantarflexion, inversion, and eversion). Correlation analysis showed that the AE of the plantarflexion force sense was significantly moderately correlated with medial-lateral sway velocity in the one-leg standing with eyes open and closed conditions (r=.372-.403, P=.006-.012), and the AE of inversion force sense was significantly moderately correlated with medial-lateral sway velocity in the one-leg standing with eyes open (r=.345, P=.018) in athletes with CAI, but the joint position sense measures were not (all P>0.05). ConclusionsAthletes with CAI showed significantly impaired balance control performance and diminished ankle proprioception. Deficit in force sense was deemed as a moderate predictor of one-leg standing balance control deficits in athletes with dominant-side injury CAI, whereas ankle position sense may be a small predictor.

The Impact of Different Anterior Cruciate Ligament Status on Unicompartmental Knee Arthroplasty: Short Term Clinical and Functional Results

Purpose: Purpose of this study is to compare the short-term results of unicompartmental knee arthroplasty applied stable knees regardless of the condition of the ACL and the application of unicompartmental knee arthroplasty and ACL reconstruction combined surgery applied to ACL deficient cases with anterior instability and to identify the condition and function of the ACL for success in this surgery. Patients and Methods: 80 out of the 105 patients who were operated in 2013-2015 and came for follow-up were included in the study and the patients were divided into four groups. The VAS pain score, KSS Score, WOMAC score, OKS questionnaires and joint range of motion measurements were conducted pre-operatively and post-operatively. One leg standing test, joint position sense measurement, and isokinetic muscle strength test were performed in post-operative controls. Results: There was no statistically significant difference between the demographic data and follow-up of the groups (p˃0.05). While there was a statistically significant difference in knee flexion between Group 2-Group 4 and Group 3-Group 4 in the pre-operative period, no difference was found in the post-operative period (p˃0.05). While there was no difference among the groups, knee joint range of motion in direction of extension declined in a statistically significant way in all four groups (p˂0.05). Pain felt postoperatively was the most in Group 1 and the least in Group 3. A statistically significant difference was found between Group 1 and Group 3 in the test performed with the eyes closed (p˂0.05). Conclusion: The presence of a functional anterior cruciate ligament is expected to make a positive contribution to surgical results especially in young patients with high activity expectation. Whether the patient’s ACL rupture is primary or secondary and his/her activity expectation should be effective in the choice of a surgical method.

The effects of thoracic mobility versus lumbopelvic stabilization exercises on lower extremity flexibility, dynamic balance and proprioception in patients with chronic ankle instability

BACKGROUND: Chronic ankle instability (CAI) presents neuromuscular control and functional performance difficulties. Although ankle-focused rehabilitation is widely practised, the relative effects of exercises targeting thoracic mobility and lumbopelvic stabilization in addressing CAI have not been thoroughly investigated. OBJECTIVE: The study aims to compare the effects of thoracic mobility and lumbopelvic stabilization exercises in patients with CAI. METHODS: The study was designed as a prospective randomized controlled clinical trial. A total of 30 participants (mean age = 31.93 ± 7.31; 21F/9M) who scored 27 points or on the Cumberland ankle instability tool voluntarily were enrolled in the study. The participants were randomly divided into two groups. In addition to the rehabilitation protocols, each participant was given a home exercise program, including ankle-strengthening exercises (3 times a week). The first group trained with thoracic mobility (TM), while the second group did lumbopelvic stabilization (LS) exercises under supervision twice a week for eight weeks. Participants’ pre and post-treatment assessments spanned an 8-week rehabilitation period, during which ankle and hip joint range of motion measurements were obtained using an electronic goniometer. Additionally, dynamic balance was assessed through the Y balance test, while ankle proprioception was evaluated using joint position sense measurements. The flexibility was assessed with an active straight leg raise test. RESULTS: Y balance, CAIT, and active straight leg raise test scores were improved in the eighth week in the thoracic mobility group (p< 0.05), while only active straight leg raise test and CAIT scores were significantly different in the lumbopelvic stabilization group (p< 0.05) according to intra group variables. In comparing the post-treatment scores between the groups, the thoracic mobility group had superior results in the joint position sense test for the right side of the hip and plantarflexion. (hip; TM: 70.71 ± 6.80, LS: 68.76 ± 5.50, plantarflexion; TM: 44.24 ± 7.28, LS: 38.30 ± 5.08). CONCLUSION: The findings suggest that while both interventions are effective in addressing various aspects of ankle instability, the thoracic mobility exercises may offer additional benefits, particularly in enhancing joint position sense, thereby providing valuable insights for the optimization of rehabilitation protocols for individuals with chronic ankle instability.

Lumbar joint position sense measurement of patients with low back pain.

Lumbar position sense can be assessed by measurement instruments including the goniometer, isokinetic dynamometry, and electronic motion monitoring equipment, which have demonstrated relatively high reliability. This literature provides a comprehensive overview of influencing factors of lumbar position sense measurement, including repositioning method, fatigue degree, and posture during the reposition. It highlights the significant role of muscle proprioception, which contributes to greater accuracy in active reposition compared to passive reposition. The differences in lumbar position sense with different measurement positions may be explained by the presence of mechanoreceptors in the load-bearing structures of the lumbar spine, especially in the facet joint capsules. These mechanoreceptors play a crucial role in providing sensory feedback and proprioceptive information pertaining to the position and movement of the lumbar spine. Individuals with low back pain (LBP) demonstrate alterations in lumbar position sense compared to those without LBP. The auto motor sensory feedback transmission mechanism of patients with non-specific LBP was more unstable than that of healthy people. These findings suggest that lumbar position sense may play a potential role in the development and perpetuation of LBP. At present, the commonly used clinical assessment methods for determining position sense include both active and passive repositioning. However, neither method exhibits high sensitivity and specificity, leading to the poor comparability of relevant studies and posing challenges for clinical application.

A prospective study of joint position sense after anterior cruciate ligament injury, reconstruction with a bone-patella tendon-bone graft, and rehabilitation

BackgroundDisruption of the anterior cruciate ligament (ACL) is associated with significant biomechanical and neuromuscular changes including deficits in joint proprioception. While previous studies have assessed joint position sense (JPS) in ACL deficient knees, methods have varied and few have done so with prospective study designs. The specific aim of this investigation was to determine the effect(s) of ACL reconstruction and recovery time may have on JPS. MethodsIn this prospective study, we assess the effects of ACL reconstruction and rehabilitation on joint position sense in a temporal study. Twelve patients with unilateral ACL injuries were assessed pre-operatively and at 2, 4, 8 months post-op. JPS measurements were performed, while the subject was standing, with passive-active (P-A) and active-active (A-A) tests. Comparisons between the injured/reconstructed and contralateral, uninjured knee were evaluated in terms of real and absolute mean errors. ResultsThere were no statistically significant differences between the injured/reconstructed and contralateral/normal side with P-A or A-A testing at 2, 4, or 8 months. ConclusionWe conclude that there is no difference in joint position sense between the injured and contralateral leg after ACL disruption and reconstruction beginning as early as 2 months post-op. This study provides further evidence that knee proprioception is not altered by ACL injury and reconstruction. Level of evidence: II.

Test-Retest Reliability of a New Device Versus a Long-Arm Goniometer to Evaluate Knee Proprioception.

Many methods used to evaluate knee proprioception have shortcomings that limit their use in clinical settings. Based on an inexpensive 3D camera, a new portable device was recently used to evaluate the joint position sense (JPS) of the knee joint. However, the test-retest reliability of the new method remains unclear. This study aimed to evaluate the test-retest reliability of the new device and a long-arm goniometer for assessing knee JPS, and to compare the variability of the 2 methods. Prospective observational study of the test-retest reliability of knee JPS measurements. Twenty-one healthy adults were tested in 2 sessions with a 1-week interval. Three target knee flexion angles (30°, 45°, and 60°) were reproduced in each session. Target and reproduced angles were measured with both methods. Intraclass correlation coefficients, standard error of the measurement, and Bland-Altman plots were used to quantify test-retest reliability. Paired t tests were used to compare knee JPS (absolute error of the target-reproduced angle) between the methods. The new device (good to excellent intraclass correlation coefficients .74-.80; standard error of the measurement 0.52°-0.61°) demonstrated better test-retest reliability than the goniometer (poor to fair intraclass correlation coefficients .23-.43; standard error of the measurement 0.89°-2.07°) and better test-retest agreement (respective mean differences for the 30°, 45°, and 60° knee angles: 0.11°, 0.13°, and 0.41° for the new system; 0.84°, 1.52°, and 1.18° for the goniometer). The measurements (absolute errors of the target-reproduced angles) with the goniometer were significantly greater than those with the new device (P < .05); the SDs of repeated measurements with the goniometer (1.50°-2.41°) were greater than with the new device (1.08°-1.38°). Given that the new device has good reliability and sufficient precision, it is the better alternative for evaluating knee JPS. Goniometers should be used with caution to assess knee JPS.

Effect of psoriatic arthritis on the strength, proprioception, skill, coordination, and functional condition of the hand.

This study was planned to evaluate the strength, proprioception, skill, coordination, and functional condition of the hand in individuals with psoriatic arthritis and to correlate disease activity with these parameters. Fifty-six individuals (psoriatic arthritis group, n=36; control group, n=20) were included in the study. Evaluations were performed of disease activity with Disease Activity Score 28; grip strength with a dynamometer and pinch strength with pinch gauge dynamometers; joint position sensation with a goniometer; finger skills with a mobile application; and coordination and skill of both hands with the Purdue Pegboard test. The Michigan Hand Outcomes Questionnaire (MHQ) was used for hand functional evaluation. There was a significant difference between the grip and pinch strength of the psoriatic arthritis group and the control group (P<0.05). There was no significant difference between the joint position sense measurements and the mobile application scores between the groups (P>0.05). Purdue Pegboard scores showed a significant difference only in both hands and assembly subsections (P<0.05). With Disease Activity Score 28, significant correlations were found between grip and pinch strength, mobile application scores, Purdue Pegboard all subsections, and left-hand joint position sense average error amount, and between MHQ and grip and pinch strength. This study is the first to show that psoriatic arthritis has a negative effect especially on hand strength; grip strength decreases as disease severity increases and, skill, coordination, and functionality of hand deteriorate.

Reliability of joint position sense measured in the knee using the level function of the iPhone "Measure" application.

An impaired joint position sense (JPS) causes activity limitations, postural imbalance, and falls. This study compares the reliability of knee JPS measurements between the iPhone’s “Measure” application and VICON motion capture system. Eleven healthy participants were recruited for the study. To conduct the study measures, the blindfolded participant, with an iPhone fixed to the lower non-dominant leg, was seated with their lower limbs in a relaxed position. The examiner held the participant’s leg at the target angle (30°/60° from initial position) for 5 s before releasing it. The participant was then instructed to move the leg to the same target angle and hold it for 5 s (replicated angle). Absolute angular error (AAE), i.e., the difference between the target and replicated angles, was measured. Intraclass and Pearson correlation coefficients established statistically significant relationships. The study comprised 6 males and 5 females of mean age 27.6±5.6 years, mean height 1.67±0.10 m, and mean body weight 60.7±10.3 kg. Strong correlations existed between iPhone and VICON 30° (ICC = 0.969, r = 0.960, P < 0.001) and 60° AAEs (ICC 0.969, r = 0.960, P < 0.001). Bland-Altman plots showed a mean difference of 0.43° and 0.20° between the AAE measurements at 30° and 60°, respectively. The iPhone’s “Measure” application is a simple and reliable method for measuring JPS in clinical practice and sports/fitness settings.

ASSESSMENT OF KNEE JOINT POSITION SENSE IN PATIENTS WITH MULTIPLE SCLEROSIS

Purpose: Multiple sclerosis (MS) disrupts joint position sense (JPS). The aims were: - to assess the JPS of knee extensors, using three target angles in MS patients and in healthy; - to estimate the changes in reproducing the joint position by using absolute (AE), constant (CE) and variable error (VE) and the effect of sex on knee JPS acuity. Subjects and Methods: Twenty MS patients and twenty healthy were tested, by knee joint angle reproduction with three targets (20o, 60o, 75o), by passive and active mode, without visual and verbal feedback. JPS measurement was done using isokinetic dynamometry. Deviations from the targets were calculated as AE, VE and CE, which correspond to accuracy, precision and direction of the bias, respectively. Results: Increased values of AE and sex differences in JPS accuracy in MS individuals, as compared with healthy, were: - at targets 20o and 60o in females in passive mode in both legs; - at 60o in the involved leg in males (more pronounced as compared with females); and – at 75o in the less involved leg, in passive reproduction in women and active in men. The significantly increased negative CE indicates a more pronounced deficit in males with MS at 60o in the involved leg and at 75o in less involved leg. Increased VE in passive repositioning was also proved (p&lt;0.05) in females with MS at 20o and 60o. Conclusion: These results suggest impaired proprioceptive performance and sex differences in MS individuals. The findings provide information to recommend appropriate strategies for the evaluation and treatment of proprioceptive deficits.

Reliability of Image Capture Technique for the Measurement of Upper Limb Active Joint Position Sense in Healthy Adults

Objective: Proprioception is the conscious perception of limb position, motion, balance, and pressure. It has a vital role in movement control, especially motor planning and neuromuscular feedback mechanism. To investigate the proprioceptive function, it is essential to use the best measurement method. Different techniques and approaches have been introduced, which are usually expensive and not applicable for clinical use. One of these methods is the image capture technique which is easy and practical. Stillman introduced this technique to measure the joint position sense of the knee considering all variables affecting it and reported its good reliability. Many studies have used this technique for knee and lower limb joints and reported its good reliability, while few studies have used this technique for the upper limb joints. Therefore, this study investigates the reliability of the image capture technique for measuring the Active Joint Position Sense (AJPS) of the left shoulder and elbow in healthy adults. If it yields a good result, it can be used as an available and cost-effective method by clinicians. Materials &amp; Methods: In this methodological study, the participants were 10 healthy adults (5 men, 5 women) aged 18-40 years. To assess the AJPS, we used image capture technology which is one of the most reliable methods for the lower limb joint position sense measurement. Markers were attached on elbow and shoulder landmarks, and photos were taken during the reproduction of angles by participants. Then, the photos were entered into AutoCAD software, and the angles were calculated by drawing line segments from landmarks and connecting them. The absolute error and relative error (the difference between the initial and reproduced angles) were used to measure accuracy. The AJPS was assessed for internal and external rotation of the shoulder and elbow flexion. The measurements were repeated two hours later to assess intra-day reliability and two days later to assess inter-day reliability. Interclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM) were used for statistical analysis. Results: The ICC of inter-day reliability of the test for all shoulder and elbow movements in relative and absolute errors was reported as excellent (≥0.92). Intra-day reliability was reported excellent (≥0.90) for elbow flexion, and internal rotation of the shoulder in both relative and absolute errors were excellent (0.94). For external rotation of the shoulder, it was excellent in relative error (0.94) and good in absolute error (0.80). All measurements had absolute reliability based on the SEM results. Conclusion: The image capture technique is a simple, cost-effective, and available method tool for measuring AJPS and proprioception in upper limbs by clinicians and researchers.

Lower limb joint position sense and prospective hamstring injury

BackgroundThe hamstrings remain the most injured muscle group within the Australian Football League (AFL). ObjectiveTo investigate preseason measures of hip and knee joint position sense (JPS) and prospective hamstring injury in AFL players. DesignProspective cohort study. MethodsA total of 116 AFL players were recruited for this study. JPS was assessed with 3-D sensors using mono-articular hip (45° flexion and 0°) and knee (90° and 45° flexion) joint reproduction tests conducted in the preseason. Hamstring injury data were collected prospectively in the following AFL season. Wilcoxon-signed rank tests were used to assess between the subsequently injured and uninjured limbs. Mann-Whitney U tests were used to assess between group differences and odds ratio (OR) were used to predict players at risk of hamstring injury. ResultsEight players with JPS data sustained a season hamstring injury and 108 players did not. JPS was not significantly different between the subsequently injured and uninjured limbs (all P values > 0.05). No significant differences for any JPS measure were found between the subsequently injured and uninjured players (all p's > 0.05). ORs did not achieve significance for AE (2.7, p = 0.21) or for RMSE (OR = 1.9, p = 0.44). ConclusionLower limb JPS measures were not predictive of hamstring injury in AFL players.

Validity and reliability of smartphones in measuring joint position sense among asymptomatic individuals and patients with knee osteoarthritis: A cross-sectional study

BackgroundQuantifying proprioception deficit in patients with osteoarthritis (OA) may be important in evaluating treatment effectiveness. This study investigated the concurrent and known-groups validity as well as test–retest reliability of a smartphone application in assessing joint position sense (JPS) in asymptomatic individuals and patients with knee OA. MethodsSixty-four knees, from 16 asymptomatic controls and 16 patients with bilateral OA, were assessed twice with a 1-week interval in between. The smartphone Goniometer Pro application and isokinetic dynamometer simultaneously quantified JPS, in terms of absolute repositioning error (RE) angle, during active and passive limb movements at selected angles. ResultsBoth devices showed moderate to almost perfect correlations in measuring JPS; whether active (intra-class correlation coefficient (ICC) >0.87) or passive (ICC >0.97). The mean RE angle differences between the two devices were <0.77° (passive JPS) and <2.76° (active JPS). Both devices were capable of distinguishing patients and asymptomatic controls at 55° and 80°. The smartphone showed moderate test–retest reliability of active JPS measurement (ICC = 0.51) in the two groups, similar to that of the isokinetic dynamometer (ICC = 0.62), but with a high measurement error. ConclusionsSmartphone application is a valid alternative to the isokinetic dynamometer in assessing JPS in patients with knee OA and asymptomatic controls. The two devices could distinguish patients and asymptomatic volunteers during passive JPS measured at 55° and 80°. Both devices have moderate reliability in quantifying active JPS, but reliability results should be considered with caution.

Moderate kinesio taping stretch tension produced good inter-day reliability of dorsiflexion joint position sense measurement

Moderate kinesio taping stretch tension produced good inter-day reliability of dorsiflexion joint position sense measurement

The Relationship Between Quadriceps Muscle Atrophy and Proprioception Function in Knee Osteoarthritis Patients

Background: Osteoarthritis of the knee (OA) patients can experience impaired proprioceptive function which causes instability, balance disorder and limited activity. Further analysis is needed to detect changes that occur. There are two methods to evaluate the speed and angle of a particular motion as an analysis of the function of proprioception, Time to Detect Passive Movements (TTDPM) and Joint Position Sense (JPS).Aim: To analyze the relationship between quadriceps muscle atrophy with proprioception in knee osteoarthritis patients.Methods: The design of this research is cross sectional analysis done in Dr. Soetomo General Hospital Surabaya, Indonesia. There were 25 knee OA patients (2 men and 23 women) with each subject had proprioception (JPS and TTDPM) function measured using isokinetics dynamometer on both sides of the knee.Results: This study shows the atrophic side had greater pain intensity and greater disturbance of proprioception. In addition, there were significant differences in JPS measurements at angle of 30⁰, and 60⁰ and TTDPM (p &lt;0.05). No difference obtained at 45⁰ measurements angle.Conclusion: In this study, there was no association between quadriceps atrophy and function of proprioception in knee osteoarthritis patients. This was due to a number of confounding factors that cannot be controlled such as duration, difference in pain intensity, OA severity, physical activity before measurement, and fatigue which can affect proprioception function and bring misinterpretation on measurements.

The Relationship Between Quadriceps Muscle Atrophy and Proprioception Function in Knee Osteoarthritis Patients

Background: Osteoarthritis of the knee (OA) patients can experience impaired proprioceptive function which causes instability, balance disorder and limited activity. Further analysis is needed to detect changes that occur. There are two methods to evaluate the speed and angle of a particular motion as an analysis of the function of proprioception, Time to Detect Passive Movements (TTDPM) and Joint Position Sense (JPS).Aim: To analyze the relationship between quadriceps muscle atrophy with proprioception in knee osteoarthritis patients.Methods: The design of this research is cross sectional analysis done in Dr. Soetomo General Hospital Surabaya, Indonesia. There were 25 knee OA patients (2 men and 23 women) with each subject had proprioception (JPS and TTDPM) function measured using isokinetics dynamometer on both sides of the knee.Results: This study shows the atrophic side had greater pain intensity and greater disturbance of proprioception. In addition, there were significant differences in JPS measurements at angle of 30⁰, and 60⁰ and TTDPM (p &lt;0.05). No difference obtained at 45⁰ measurements angle.Conclusion: In this study, there was no association between quadriceps atrophy and function of proprioception in knee osteoarthritis patients. This was due to a number of confounding factors that cannot be controlled such as duration, difference in pain intensity, OA severity, physical activity before measurement, and fatigue which can affect proprioception function and bring misinterpretation on measurements.

Test-Retest Reliability of Isokinetic Wrist Strength and Proprioception Measurements.

The evaluation of the wrist strength and proprioception gives clinicians and researchers information about effectiveness of their rehabilitation protocol or helps diagnosis of various neuromuscular and somatosensorial disorders. Isokinetic dynamometers are considered the gold standard for these evaluations. However, the studies about test-retest reliability of isokinetic dynamometer are inadequate. The purpose of this study was to determine the test-retest reliability of isokinetic wrist strength and proprioception measurements using the Cybex isokinetic dynamometer. Test-retest reliability study. University laboratory. Thirty participants were enrolled (age 23.2 [2.8]y, height 171.1 [7]cm, weight 66.6 [11.6]kg) in this study. Cybex isokinetic dynamometer was used for strength and proprioception measurements. Concentric flexion-extension strength test was performed at 90°/s angular velocity, and eccentric flexion-extension strength test was performed at 60°/s angular velocity. The proprioception of the wrist was assessed via active joint position sense. The 30° extension of the wrist, which is accepted as the functional position of the wrist, was selected as the targeted angle. The intraclass correlation coefficient (ICC2,1) method was used for test-retest analysis (P < .05). The active joint position sense measurements of dominant (ICC2,1: .821) and nondominant (ICC2,1: .763) sides were found to have good test-retest reliability. Furthermore, with the exception of dominant eccentric extension strength (moderate reliability) (ICC2,1: .733), eccentric and concentric flexion (dominant: ICC2,1 = .890-.844; nondominant: ICC2,1 = .800-.898, respectively), and extension (dominant: ICC2,1 = .791 [concentric], nondominant: ICC2,1 = .791-.818, respectively) strength measurements of both sides were found to have good reliability. This study shows that the Cybex isokinetic dynamometer is a reliable method for measuring wrist strength and proprioception. Isokinetic dynamometers can be used clinically for diagnosis or rehabilitation in studies which contain wrist proprioception or strength measurements.

The effects of scapular muscle fatigue on scapular sensorimotor system

Muscle fatigue may affect scapular sensorimotor system severely because scapula is surrounded by lots of muscles, which not only provide proprioception but also control movements. However, the effects of scapular muscle fatigue on scapular joint position sense and kinematics are uncertain. The aims of this study are to investigate the effects of scapular muscle fatigue on scapular joint position sense and neuromuscular performances. We recruited 30 healthy adults. They received the measurements of scapular joint position sense (reposition error), muscle power, and kinematics during scaption (arm elevation in scapular plane) along with muscle activation before and after a fatigue protocol. Our fatigue protocol used repeatedly holding at modified push-up plus position to exhaust scapular muscles including upper, lower trapezius, and serratus anterior. Post-measurements would start when participants finished all repetitions or could no longer do one more repetition. The repeated measured analysis of variance (ANOVA) used to assess the effects of fatigue on scapular reposition error, muscle power, kinematics, and muscle activation. The level of statistical significance was set at P < 0.05. All subjects fatigued by confirming the median frequency of either one of three muscles dropped more than 10% during the last repetition. Muscle power of upper trapezius and serratus anterior dropped statistically significantly. Although the reposition error did not change, muscle activation of serratus anterior increased (18.746% to 26.344%, P = 0.006 in elevation; 15.217% to 27.406%, P = 0.037 in protraction) during joint position sense measurements. In 120° scaption, scapula decreased posterior tilt (13.813° to 10.334°, P = 0.000147); increased internal rotation (10.212° to 13.246°, P = 0.004); increased upperward rotation (52.776° to 54.351°, P = 0.005). Muscle activation of serratus anterior increased (65.914% to 84.611%, P = 0.002) in 90° ∼ 120° scaption. Scapular muscles fatigued did not alter scapular joint position sense, but neuromuscular performances such as scapular kinematics and muscle activation of serratus anterior were changed.

A reliable and accurate system of joint position sense measurement

Objective: Measurement of range of motion is used to measure the joint Position Sense (JPS). The objective of this study was to give an easy and less costly method of measuring JPS. Methods: The study conducted at Tehran University of Medical Sciences, in Iran in May 2017. In this study researcher used the system of digital photographs, non-reflective markers and software for measuring the accuracy and reliability. The fixed arm of the goniometer was horizontal. The moveable arm was positioned at the 15° initially and then selected it at different degrees (30, 45, 60 and 75) randomly. 5 reference angles were selected from 15° to 75°. By using moving arm three photos were taken from each angle. Reliability and validity of measurement for each angle was disclosed by utilizing T-test, correlation (reliability test) and R square of regression (validity test). Also relative and absolute error is used to evaluate the accuracy of this method. Results: Results showed that mean (R^2) for validity is 0.99, T-test p-value for reliability is 0.41 it means there is no significant difference between these methods and for correlation (reliability) mean value was 0.97 and averages of absolute error and relative error were (-0.44 and 0.62) respectively. Conclusion: It was disclosed that method comprising of digital photography non-reflective markers showed similar results as compared to goniometer in terms of reliability, validity and accuracy of this method. In conclusion, it was a novel approach to measure JPS with salient features of user friendly, fast, less expensive, accurate and reliable.

Stiffness and proprioceptive contributions of ankle braces and the influence of localized muscle fatigue

Ankle braces are a common treatment to reduce ankle sprain recurrence among individuals with chronic ankle instability (CAI). Bracing provides supplemental external joint stiffness and/or improved proprioceptive acuity. The goals of this study were to assess the effects of two ankle braces on joint position sense (JPS) and ankle stiffness, and determine whether bracing effects are reduced with localized muscle fatigue. Measures of JPS and ankle stiffness were obtained from participants with CAI (n=12) for three conditions (no brace, a neoprene wrap brace, and a semi-rigid brace), before and after inducing localized muscle fatigue at the ankle. Pre-fatigue JPS measures did not differ between brace conditions, but pre-fatigue stiffness was ∼0.8 and 2.5Nm/rad (∼5 and 14%) greater for the semi-rigid brace than the neoprene and no brace conditions, respectively. Fatigue increased absolute JPS errors by 0.3° (∼6 to 12%) across all conditions. Stiffness was unaffected by fatigue among females. Among males, fatigue increased stiffness by 0.75Nm/rad (∼3.3%) with the semi-rigid brace and decreased stiffness by 0.32Nm/rad (1.5%) with no brace. The semi-rigid brace may better protect males from sprains while either brace may be effective for females.

Validity of an ankle joint motion and position sense measurement system and its application in healthy subjects and patients with ankle sprain

Background and objectiveAnkle motion and proprioception in multiple axis movements are crucial for daily activities. However, few studies have developed and used a multiple axis system for measuring ankle motion and proprioception. This study was designed to validate a novel ankle haptic interface system that measures the ankle range of motion (ROM) and joint position sense in multiple plane movements, investigating the proprioception deficits during joint position sense tasks for patients with ankle instability. MethodsEleven healthy adults (mean ± standard deviation; age, 24.7 ± 1.9 years) and thirteen patients with ankle instability were recruited in this study. All subjects were asked to perform tests to evaluate the validity of the ankle ROM measurements and underwent tests for validating the joint position sense measurements conducted during multiple axis movements of the ankle joint. Pearson correlation was used for validating the angular position measurements obtained using the developed system; the independent t test was used to investigate the differences in joint position sense task performance for people with or without ankle instability. ResultsThe ROM measurements of the device were linearly correlated with the criterion standards (r = 0.99). The ankle instability and healthy groups were significantly different in direction, absolute, and variable errors of plantar flexion, dorsiflexion, inversion, and eversion (p < 0.05). ConclusionsThe results demonstrate that the novel ankle joint motion and position sense measurement system is valid and can be used for measuring the ankle ROM and joint position sense in multiple planes and indicate proprioception deficits for people with ankle instability.