Joint Position Sense Error Research Articles

Influence of Cervical Spine Manipulation on Neck Joint Position Sense error in patients with chronic neck pain.

Introduction: Cervical joint dysfunction may interfere with the sensorimotor afferent response, interfering with neck neck Joint Position Sense error (JPS). Objective: The aim of this study was to evaluate the influence of Cervical Spine Manipulation (CSM) on neck JPS error in patients with chronic neck pain. Method: 21 patients with chronic neck pain were divided into 2 groups: Spinal Manipulation Group (MG) or Sham Group (SG) who received 4 sessions of CSM and Sham CSM respectively. JPS was assessed in three different time frames: 1) pre-intervention; 2) Right after the first intervention (post-intervention 1); and 3) After a chronic intervention (post-intervention 2). The outcome measured in this study was the head reposition accuracy test with the Revel’s Test. Results: The JPS showed no significant differences between pre- and post-intervention 1 and 2 for any of the assessed groups. Conclusion: We conclude that, for this sample, neither the CSM nor the Sham CSM statistically changed the JPS error for neither groups. We believe that the changes in JPS after CSM were concealed because the ability of other sensory system information to compensate for inadequacies in any other component. Therefore, more studies have to be done with a stronger methodological rigor, clinical prediction rule for spinal manipulation, bigger sample and a blind assessment.

Joint position sense error and muscle torque ratios of agonist and antagonist muscles in the ankle and knee joints of young adults.

Many studies have investigated the correlation between muscle torque and joint position sense (JPS), but few studies have been performed on the correlation between torque ratio and JPS. The aim of this study was to investigate JPS and muscle torque ratios of agonist and antagonist muscles in the ankle and knee joints of young adults. A total of 38 right handed healthy participants, 12 males and 26 females, were recruited. All participants measured their peak torque of knee flexor/extensor and ankle dorsiflexor/plantar flexor by using a Biodex system. They also used the Biodex to assess the proprioception through active joint reposition sense test in knee and ankle joint. Peak torque of each muscle, agonist/antagonist torque ratio and JPS error were collected, and Pearson's correlation analysis was used to examine correlations between peak torque, torque ratio and JPS error. For knee joints, correlations were found between flexion and extension torque, extension torque and torque ratio, and torque ratio and JPS error (r= 0.825/p= 0.000, r=-0.482/p= 0.002, and r=-0.685/p= 0.000, respectively). For ankle joints, correlations were found between dorsiflexion and plantar flexion torques, plantar flexion torque and torque ratio, plantar flexion torque and JPS, and torque ratio and JPS (r= 0.654/p= 0.000, r=-0.621/p= 0.000, r=-0.563/p= 0.000, and r=-0.761/p= 0.000, respectively). JPS error of lower extremity joint may be more related with agonist/antagonist torque ratio rather than peak torque. Therefore, people who will have training for reducing JPS error need to consider torque ratio, too.

The immediate effect of lumbopelvic manipulation on knee pain, knee position sense, and balance in patients with patellofemoral pain: A randomized controlled trial

BackgroundPatellofemoral pain (PFP) is a common musculoskeletal disorder. Quadriceps and core muscle neuromuscular control impairments are frequently associated with PFP. Lumbopelvic manipulation (LPM) has been shown to improve quadriceps and core muscle activation and decrease their inhibition, but changes in balance and knee joint position sense (JPS) after this intervention remain unknown. ObjectiveTo determine whether LPM decreases knee pain and JPS error and increases balance performance in patients with PFP. DesignRandomized controlled trial. SettingBiomechanics laboratory at a rehabilitation science research center. MethodsForty-four patients with PFP participated in this study that randomly divided into two equal groups. One group received LPM and the other received sham LPM (positioning with no thrust) in a single session. At baseline and immediately after the intervention, the outcomes of pain using a visual analog scale, balance using the modified star excursion balance test (mSEBT), and JPS at 20° and 60° of knee flexion using a Biodex dynamometer. ResultsThere was a statistically significant improvement in pain, balance control (anterior direction) and JPS in the LPM group immediately after the intervention. In addition, we observed significant differences between groups in pain, balance control (anterior direction) and JPS at 60° of knee flexion immediately after the intervention. ConclusionA single session of LPM immediately improved balance control, knee JPS, and pain in patients diagnosed with PFP. Clinical rehabilitation impactFindings suggest that LPM may be used as a therapeutic tool for immediate improvement of symptoms of PFP. However, more research is needed to determine long term results.

Effects of local vibration and cervical stabilization exercises on balance, joint position sense, and isometric muscle performance in young adults: A randomized controlled study

BACKGROUND: Cervical stabilization exercises and local vibration may improve proprioception and balance and prevent musculoskeletal problems. OBJECTIVE: To compare the effects of local vibration and cervical stabilization exercises on balance, cervical joint position sense, and muscle performance in healthy participants. METHODS: Forty-eight healthy male participants without neck pain were included. The participants were randomly divided into three groups: a home exercise program lasting eight weeks to the cervical stabilization group; 60 s of vibration to the neck muscles of the local vibration group and a control group. Balance, joint position sense, and muscle performance were evaluated twice in all subjects, before and after the intervention. RESULTS: Joint position sense error values were decreased in both the local vibration and cervical stabilization groups. Balance was improved (p< 0.001) in the local vibration group while improvement in muscle performance parameters was only seen in the cervical stabilization group (p< 0.05). CONCLUSIONS: The methods used in the present study may be used for improving the proprioceptive and vestibular components of balance in individuals with musculoskeletal problems such as cervical disc herniation, cervical spondylosis, or neck pain. However, given the limitations, much more research is needed to firmly establish these recommendations.

Acute effect of flexible bar exercise on scapulothoracic muscles activation, on isometric shoulder abduction force and proprioception of the shoulder of individuals with and without subacromial pain syndrome

BackgroundThere is currently no evidence about the effects of neuromuscular facilitation after the use of a flexible bar on scapulothoracic muscle activity in individuals with subacromial pain syndrome. The study aimed to assess the acute effect of flexible bar exercise and subjective fatigue on scapulothoracic muscle activity, shoulder proprioception, and shoulder abduction force of subjects with and without symptoms of subacromial pain syndrome. MethodFifty subjects with subacromial pain syndrome and 50 asymptomatic subjects were recruited. A short-term flexible bar exercise was performed to assess the vibratory stimulus effects on scapulothoracic muscle activity, shoulder proprioception, and shoulder abduction force, and the same exercise was performed on a long-term basis to assess the effects of subjective fatigue. The activities of the serratus anterior and three portions of the trapezius muscle were investigated using surface electromyography during arm elevation. The active joint position sense error was assessed to determine shoulder proprioception using a laser pointer. A hand-held dynamometer was used to assess isometric shoulder abduction force. FindingsNo significant intra-group differences were found in scapulothoracic muscle activity, as well as in active joint position sense error and isometric shoulder abduction force in either group (p >0.05). InterpretationThe acute effects of flexible bar exercise and subjective fatigue were unable to influence scapulothoracic muscle activation, shoulder joint position sense, and isometric shoulder abduction force in subacromial pain syndrome.

Somatosensory Function Influences Aberrant Gait Biomechanics Following Anterior Cruciate Ligament Reconstruction.

Osteoarthritis is common following anterior cruciate ligament reconstruction (ALCR), and aberrant gait biomechanics are considered a primary contributor. Somatosensory dysfunction potentially alters gait biomechanics, but this association is unclear. Therefore, the purposes of this investigation were to compare somatosensory function between limbs and evaluate associations between somatosensory function and gait biomechanics linked to osteoarthritis development in individuals with ALCR. Seventy-three volunteers with ALCR participated. Gait biomechanics (peak vertical ground reaction force magnitude and loading rate, peak internal knee extension and valgus moments, peak knee flexion and varus angles, and quadriceps/hamstrings co-activation) were assessed as subjects walked at their preferred speed. The somatosensory function was assessed via joint position sense error (knee flexion) and vibratory perception threshold (femoral epicondyles, malleoli, and first metatarsal). Though somatosensory function did not differ between the ACLR and contralateral limbs, poorer joint position sense in the ACLR limb was associated with lower loading rates and internal knee extension moments, and greater co-activation. Poorer vibratory perception at the medial and lateral malleoli and first metatarsal head in the ACLR limb was associated with lower loading rates, greater internal knee valgus moments and varus angles, and greater co-activation. Poorer vibratory perception at the medial malleolus and first metatarsal head in the contralateral limb was associated with greater peak knee varus angles and internal knee valgus moments. These results suggest that future research evaluating rehabilitation approaches for improving somatosensory function is warranted as a potential approach for restoring normal gait biomechanics and reducing osteoarthritis risk. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:620-628, 2020.

Neuromuscular changes in football players with previous hamstring injury

BackgroundImpact of prior injury on myoelectrical activity of the hamstrings during isokinetic eccentric contractions has received increased literature attention. This cross-sectional study aimed to assess neuromuscular adaptations, namely proprioception, core stability, muscle strength, extensibility and activity, in football players with history of hamstring strain injury. MethodsSeventeen players, 10 with history of hamstring injury and 7 without prior injury underwent isokinetic strength testing, eccentric knee extension at 30 and 120°/s. Myoelectrical activity of bicep femoris and medial hamstrings was calculated at 30, 50 and 100 ms after onset of contraction. Functional tests included core stability, muscle strength, and knee proprioception tests. FindingDifferences were observed between Hamstring Group injured and uninjured and Control Group dominant limbs in the bicep femoris activity at almost all times in both velocities (p < 0.05). Joint position sense error was higher in the injured side compared to uninjured and control dominant limb; additionally there were also differences between injured and uninjured limb in the triple-hop test. InterpretationPreviously injured side showed deficits in bicep femoris myoelectrical activity after onset of contraction during eccentric testing, proprioceptive deficits, and functional asymmetry.

Can texture change joint position sense at the knee joint in those with poor joint position accuracy?

Purpose: Skin contributes to joint position sense (JPS) at multiple joints. Altered cutaneous input at the foot can modulate gait and balance and kinesiology tape can enhance proprioception at the knee, but its effect may be dependent on existing capacity. The effect of texture at the knee, particularly in those with poor proprioception, is unknown. The aim of this study was to determine the effect of textured panels on JPS about the knee.Materials and methods: Eighteen healthy females were seated in an adjustable chair. Their left leg (target limb) moved passively from 65° to a target of flexion (115° or 90°) or extension (40°). Their right leg (matching limb) was passively moved towards this target angle and participants indicated when their limbs felt aligned. We tested three textured panels over the knee of the matching limb and two control conditions. The target limb maintained a control panel. Directional error, absolute error and variable error in matching between limbs were calculated.Results: On average textured panels over the knee increased JPS error compared to control pants for participants with poor JPS. These participants undershot the target at 90° of flexion significantly more with textured panels (−11° ± 3°) versus control (−7° ± 3°, p = 0.04).Conclusions: For participants with poor JPS accuracy, increased JPS error at 90° with a textured panel suggests these individuals utilised altered cutaneous information to adjust joint position. We propose increased error results from enhanced skin input at the knee leading to the perception of increased flexion.

Relationship between Hip Joint Position Sense and Balance Abilities

[Purpose] To investigate the correlation between joint position sense (JPS) during hip abduction and static/dynamic balance abilities. [Method] The study enrolled 22 healthy college undergraduates and a smartphone application known as Clinometer was used to measure JPS during hip abduction using the passive setting/active reproduction. Balance ability was measured at levels 12, 7, and 3 of the Biodex Balance System. The JPS error during hip abduction was correlated with balance ability in relation to sway level. [Results] Error in JPS during hip abduction was moderately correlated with all balance scores at all sway levels (r≥0.38, p≤0.04 for all), except for the anterior-posterior balance at levels 12 and 3 (r≤0.24, p≥0.30 for both). [Conclusion] A significant correlation existed between JPS during hip abduction and balance ability, regardless of sway level. Therefore, adequate sensory training of the hip joint is needed during balance training.

Knee sensorimotor control following anterior cruciate ligament reconstruction: A comparison between reconstruction techniques

The sensorimotor system helps to maintain functional joint stability during movement. After anterior cruciate ligament (ACL) injury and reconstruction, several sensorimotor deficits may arise, including altered proprioception and changes in neuromuscular control. It is still unknown whether the type of autograft used in the reconstruction may influence knee sensorimotor impairments. The aim of this study was to comparatively assess the effects of the hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) ACL reconstruction techniques on knee sensorimotor control 6–12 months post-operation. A total of 83 male subjects participated in this study: 27 healthy participants, 30 BPTB-operated patients and 26 HT-operated patients. Active joint position sense in 3 ranges of motion (90–60°, 60–30°, and 30–0° of knee flexion), isometric steadiness, and onset of muscle activation were used to compare sensorimotor system function between groups. Both operated groups had a small (< 5°) but significant joint position sense error in the 30–0° range when compared to the healthy group. No significant differences were found between the operated and the control groups for isometric steadiness or onset of muscle activation. The results of this study suggest that operated patients present knee proprioceptive deficits independently of surgical technique. Nevertheless, the clinical implications of this impairment are still unknown. It seems that selected surgical approach for ACL reconstruction do not affect functioning of the sensorimotor system to a large degree.

The effects of rotator cuff tear on shoulder proprioception.

To evaluate the effects of rotator cuff tear (RCT) and its severity on shoulder proprioception. We studied 132 consecutive patients (67 M-65 F; mean age ± SD, 66.03 ± 9.04; range, 43-78) who underwent arthroscopic rotator cuff repair. Tear size was determined intra-operatively. The control group included 82 subjects (38 M-44 F; mean age ± SD, 65.87 ± 8.06; range, 41-75) with no RCT. All participants, wearing an eye mask, were submitted to the evaluation of the joint position sense (JPS) at 30°, 60°, 90°, 120°, and 150° of shoulder forward flexion during the sitting position, using a digital inclinometer securely attached to the subject's arm using hook-and-loop straps. The passive placement and active replacement method was used; the order of the tested angles was randomly selected. The entire test was repeated three times. The error score, by averaging the three trials, was measured as the absolute difference between the target angle and the observed angle. Statistics were performed. The intraclass correlation coefficient for all degrees of flexion movement measured was > 0.90, exhibiting a very high correlation. We found significant differences between cases and controls regarding the results of joint position sense error at all measurements (p < 0.05). According to RCT size, we found significant differences between groups at 30° (F = 27.27, p < 0.001), 90° (F = 5.37, p = 0.006), 120° (F = 10.76, p < 0.001), and 150° (F = 30.93, p < 0.001) of shoulder flexion; in details, patients with massive RCT showed greater absolute error value than those with both small and large RCT at 30°, 90°, 120°, and 150° of shoulder flexion (p < 0.05). RCT provokes an alteration of shoulder proprioception, evaluated as the loss of joint position sense, and the impairment is related to tear severity.

An above-knee compression garment does not improve passive knee joint position sense in healthy adults.

We determined the effects of wearing an above-knee compression garment (CG) on knee joint position sense. Healthy young adults (n = 24, age = 27.46 ± 4.65 years) performed a passive knee position-matching task on an isokinetic dynamometer with each leg separately. We determined the magnitude of compression by measuring anatomical thigh cross sectional area (CSA) in standing using magnetic resonance imaging. Wearing the CG compressed CSA by 2% (t = 2.91, p = 0.010, Cohen’s d = 0.68). Repeated measures ANOVA (rANOVA) with three repetition factors (condition: CG, no CG; leg: right dominant, left non-dominant; and target angles: 30°, 45°, 60°) revealed an effect of angles (p < 0.001), where the matching of knee joint position was more accurate at 60° compared to 30° and 45° (p < 0.001). However, CG did not reduce passive joint position sense errors. In fact, joint position error was less without CG (p = 0.014). In conclusion, while CG does compress the thigh it does not afford the purported benefits for proprioception as measured by a target-matching task in the present study.

Changes in Cervicocephalic Kinesthetic Sensibility, Widespread Pressure Pain Sensitivity, and Neck Pain After Cervical Thrust Manipulation in Patients With Chronic Mechanical Neck Pain: A Randomized Clinical Trial

ObjectiveThe purpose of the current randomized clinical trial was to examine the effects of cervical thrust manipulation or sham manipulation on cervicocephalic kinaesthetic sense, pain, pain-related disability, and pressure pain sensitivity in patients with mechanical neck pain. MethodsFifty-four individuals with neck pain were randomly assigned to receive either a cervical manipulation (right or left) or a sham manipulation. Immediate outcomes included cervical kinesthetic sense as assessed by joint position sense error (JPSE) and pressure pain thresholds (PPTs). At 1 week, neck pain intensity (numerical pain rate scale) and neck pain-related disability (Neck Disability Index [NDI]) outcomes were also collected. ResultsThe mixed-model analysis of covariance revealed a significant group × time interaction in favor of the cervical thrust manipulation group for the JPSE on rotation and extension. There was also a significant interaction for changes in PPTs at C5 to C6 and tibialis anterior. At the 1-week follow-up, a significant interaction existed for neck-related disability but not for neck pain at rest, worst pain, or lowest pain experienced the preceding week. ConclusionsOur results suggest that cervical spine thrust manipulation improves JPSE, PPT and NDI in participants with chronic mechanical neck pain. Furthermore, changes in JPSE and NDI were large and surpass published minimal detectable changes for these outcome measures. In addition, the effect sizes of PPTs were medium; however, only C5 to C6 zygapophyseal joint exceeded the minimal detectable change. In contrast, cervical thrust manipulation did not improve neck pain intensity at 1 week after the intervention.

Age-Related Differences in the Relationships Between Lower-Limb Joint Proprioception and Postural Balance.

In the present study we aimed to investigate the relationships between lower-limb joint proprioception and postural balance. Age-related differences in such relationships were also identified. Impaired postural balance is reportedly one of the most common risk factors for fall accidents. Interventions have been proposed to improve postural balance by enhancing proprioceptive feedback. However, there is still no consensus on the optimal design for these interventions; therefore, there is a need to better reveal the contributions of lower-limb joint proprioception to postural balance. Twenty-eight young and 28 older adults participated. Lower-limb joint proprioception was assessed by joint position sense errors measured at the ankle, knee, and hip of the dominant side, respectively. Postural balance was assessed by using center-of-pressure measures during bilateral static stance. Ankle joint position sense error was positively correlated with root mean squared distance of the center of pressure in the anterior-posterior and medial-lateral directions in both young and older adults. Different from young adults, hip joint position sense error was positively correlated with root mean squared distance of the center of pressure in the anterior-posterior and medial-lateral directions in older adults only. Declined ankle and hip proprioception could be risk factors for falls in older adults. Age-related differences in the effects of hip proprioception suggests that hip proprioception is more important for maintaining balance in older adults. Ankle proprioception contributes the most to balance maintenance. Thus, ankle proprioception enhancement exercises should be considered in fall prevention interventions.

The short-term effect of swimming training load on shoulder rotational range of motion, shoulder joint position sense and pectoralis minor length

Shoulder pain or injury is the most common issue facing elite competitive swimmers and the most frequent reason for missed or modified training. Literature suggests that highly repetitive upper limb loading leads to inappropriate adaptations within the shoulder complex. The most likely maladaptations to occur are variations in shoulder rotational range of motion, reduction in joint position sense and shortened pectoralis minor length. This has yet to have been confirmed in experimental studies. The aim of this study was to investigate the short-term effects of swimming training load upon internal and external rotation range of motion, joint position sense and pectoralis minor length. Sixteen elite swimmers training in the British Swimming World Class programme participated. Measures of internal and external range of motion, joint position sense error score and pectoralis minor length were taken before and after a typical 2 h swimming session. Following swimming training shoulder external rotation range of motion and pectoralis minor length reduced significantly (-3.4°, p = <0.001 and -0.7 cm, p = <0.001, respectively), joint position sense error increased significantly (+2.0° error angle, p = <0.001). Internal rotation range of motion demonstrated no significant change (-0.6, p = 0.53). This study determined that elite level swimming training results in short-term maladaptive changes in shoulder performance that could potentially predispose them to injury.

Assessment Of Knee And Ankle Proprioception In Young And Old Adults Using The AMEDA

Proprioception is often associated with neuromuscular abilities and injury prevention in older persons. While several methods exist for testing proprioception, most instruments are impractical and assess joint position sense (JPS) in an artificial environment. The Active Movement Extent Discrimination Apparatus (AMEDA) offers a low-cost alternative to evaluate JPS in a natural standing environment. PURPOSE: To compare the active proprioception of the lower limbs and ankles in healthy young (YG) and older individuals (OG) using the AMEDA. METHODS: Forty-four persons (YG: n=22, OG: n=22) participated in the study. During lower limb (hip, knee) testing, participants were asked to touch a rear bar before kicking forward to strike a stop board placed at one of three positions (11cm, 16cm, 22cm). For the ankle, the foot was inverted to one of three angles (1=12o; 2=14o; 3=16o). Our testing included 3 conditions: condition 1 (C1=no difference between sequential positions), condition 2 (C2=minimal differences between sequential positions), and condition 3 (C3=maximal difference between sequential conditions). Participants were asked to identify all positions while blindfolded over the course of 50 trials. Two two-way ANOVA (condition) x (group) were used to examine the number of errors within each group at each joint position. RESULTS: The YG made significantly more errors than the OG for the left lower limb during C1 and C3 (p < .05). Furthermore, for the YG, the number of errors decreased from C1 through C3 (p<.05). The YG also produced significantly more errors than the OG in C1 for the left and right ankles (p<.05). The OG made more errors during C2 then any other condition for both ankles (p<.05). CONCLUSION: The YG made more JPS errors then the OG. These findings are contrary to the proposition that proprioception decreases with age. Based on these findings, older individuals appeared to be more aware of their knee and ankle joint positions. These differences may be attributed to the OG paying greater attention to their movement patterns during day to day activities as a precaution to reduce fall risk.

The effect of a cricket fielding session on glenohumeral range of motion and active joint position sense

ObjectiveTo assess the effects of a cricket fielding session, at an identified throwing injury risk workload, on shoulder joint position sense (JPS) and active range of motion (AROM) in cricketers. DesignRepeated measures observational study. SettingIndoor cricket centre. ParticipantsNineteen, asymptomatic University cricketers. Main outcomeAROM was assessed supine at 90° abduction and from this 10% off end range IR and ER was used as the position matching angle to assess JPS. JPS error scores as well as AROM were assessed pre and post a cricket fielding session consisting of 40 throws. ResultsFollowing the cricket fielding session, no alteration in JPS in ER (p = 0.91) or IR (p = 0.27) was observed. There was however a significant decrease in IR (−3.9°) following the fielding drill (p = 0.007) while no significant change was observed in ER or total motion. ConclusionActive IR ROM is significantly decreased immediately following a cricket fielding drill, while no alterations in JPS were observed. High levels of eccentric stress have been reported in the external rotators after throwing which may contribute to the acute musculotendinous adaptations observed. Changes in IR may be a contributing factor to workload-acquired shoulder throwing injuries.

Investigation of the relationship between pain threshold and joint position sense in the cervical region

This study was performed to investigate whether there is a relationship between cervical region pain threshold and joint position sense (JPS) in healthy subjects. The subjects were 38 healthy volunteers in the Hacettepe University, Faculty of Health Sciences, Physiotherapy and Rehabilitation Department. Pain thresholds in the right and left cervical paravertebral regions of participants were assessed with a digital algometer (Wagner Instruments, Greenwich, USA). The JPS of the cervical region was assessed with the Cervical Range of Motion 3 (CROM 3) device. While the pain thresholds in the left and right cervical paravertebral regions increased, the JPS error levels in the cervical region of the extension direction decreased (right and left cervical paravertebral region p = 0.003 and r = -0.475, p = 0.020 and r = -0.377, respectively). At the end of this study, the position sense error was higher in the participants with a low pain threshold. In participants in which the pain threshold is lower, prematurely stimulated pain receptors can decrease JPS by causing suppression of proprioceptive receptors. JPS should be assessed in individuals who define pain in the neck region. According to the result of this study, it is necessary to improve JPS in patients with neck pain, or healthy individuals who have lower pain threshold may be able to avoid neck pain when they receive appropriate proprioceptive training to improve their JPS. In conclusion, when healthy individuals were included in proprioceptive training, it was observed that neck pain could be prevented in the early period.

Effects of Static Stretching of the Calf Muscle after Microwave Diathermy on Joint Position Sensation and Dynamic Balance Ability

This study aimed to investigate the effects of static stretching of the calf muscle on ankle position sense and dynamic balance ability following microwave diathermy. Participants were 28 healthy young students in their 20 s, who were divided into a microwave diathermy stretching group (MSG) and a stretching group (SG). A microwave was emitted to the calf muscle area to participants in the MSG. Static stretching was performed by standing on a quadriceps board for 15 minutes. The angle of the wedge was set to a range of 15–25°, representing a level of pain and discomfort allowed by the subjects. Before and after intervention, ankle dorsi-plantar flexion joint position sense (JPS) and dynamic balance ability were measured. The group source affected JPS error of dorsi-plantar flexion (p 0.05) and JPS error increased with the SG more than the MSG. There was an increase in the dynamic balance score in both groups after the intervention compared to before the intervention. Microwave therapy prior to stretching can preserve JPS and balance ability, thereby reducing the risk of injuries from activities after stretching.

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.