Impact of Glycemic Control on Shoulder Proprioception in Type 2 Diabetes Mellitus: Mediating the Connection - Insights from a Cross-Sectional Analysis.

Introduction: Shoulder proprioception is vital and this cross-sectional study investigated the association between glycemic control and shoulder joint proprioception in Type 2 Diabetes Mellitus (T2DM). Methods: A total of 120 participants, including 60 with T2DM and 60 healthy individuals, were assessed for shoulder joint position sense (JPS) using a digital inclinometer. The T2DM group exhibited significantly greater mean shoulder joint position errors in flexion (4.32° vs 2.15°), abduction, medial rotation, and lateral rotation compared to the healthy group (p < 0.001). Results: The study found significantly greater shoulder joint position errors in the T2DM group compared to the healthy group, highlighting notable proprioceptive deficits in individuals with T2DM. Additionally, a significant positive correlation was found between HbA1c levels and shoulder joint position errors in the T2DM group, suggesting a link between long-term glycemic control and proprioceptive accuracy. Discussion: The significant positive correlation between HbA1c levels and shoulder joint position errors suggests that poor glycemic control is associated with impaired proprioception in T2DM patients. This underscores the need for comprehensive management strategies to mitigate proprioceptive deficits and improve the quality of life in individuals with T2DM.

Shoulder muscle weakness and proprioceptive impairments in type 2 diabetes mellitus: exploring correlations for improved clinical management.

Background: Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disorder with systemic implications, potentially affecting musculoskeletal health. This study aimed to assess shoulder muscle strength and joint repositioning accuracy in individuals with T2DM, exploring potential correlations and shedding light on the musculoskeletal consequences of the condition. The objectives were two-fold: (1) to assess and compare shoulder strength and joint repositioning accuracy between individuals with T2DM and asymptomatic counterparts, and (2) to examine the correlation between shoulder strength and joint repositioning accuracy in individuals with T2DM. Methods: A cross-sectional study enrolled 172 participants using the convenience sampling method, including 86 individuals with T2DM and an age-matched asymptomatic group (n = 86). Shoulder strength was assessed using a handheld dynamometer, while joint repositioning accuracy was evaluated with an electronic digital inclinometer. Results: Individuals with T2DM exhibited reduced shoulder muscle strength compared to asymptomatic individuals (p < 0.001). Additionally, joint repositioning accuracy was significantly lower in the T2DM group (p < 0.001). Negative correlations were observed between shoulder strength and joint repositioning accuracy in various directions (ranging from -0.29 to -0.46, p < 0.001), indicating that higher muscle strength was associated with improved joint repositioning accuracy in individuals with T2DM. Conclusion: This study highlights the significant impact of T2DM on shoulder muscle strength and joint repositioning accuracy. Reduced strength and impaired accuracy are evident in individuals with T2DM, emphasizing the importance of addressing musculoskeletal aspects in diabetes management. The negative correlations suggest that enhancing shoulder muscle strength may lead to improved joint repositioning accuracy, potentially contributing to enhanced physical functioning in this population.

Investigation of sensory and motor functions of wrist in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a systemic and autoimmune disease that affects many tissues and organs in the body, especially the synovial joint and periarticular structures. One of the most affected joints is the hand joints, and there is also involvement in the wrist joint. OBJECTIVES: The purpose of this study was to assess the sensory and motor functions of the wrist with a gold standard method and to determine the relationship between the motor and sensory functions of the wrist and wrist-related pain/disability level and hand grip strength in patients with RA. METHOD: Flexor and extensor muscle strength and joint position sense of the wrist were evaluated using isokinetic dynamometer, hand grip strength was measured using dynamometer, and wrist related pain and disability was assessed by Patient Rated Wrist Evaluation (PRWE) questionnaire. RESULTS: Thirty-one patients with RA and 31 healthy controls were included in the study. Control group had better results regarding wrist flexor and extensor muscle strength and wrist joint position sense than RA patients for both hands/wrists. A positive and strong correlation and a negative and weak correlation were found between muscle strength and joint position sense of the wrist and hand grip strength, respectively. CONCLUSIONS: Compared to healthy subjects, RA patients showed wrist-related sensorimotor deficits. Therefore, evaluation of the wrist should not be ignored in the examination of patients with RA. In addition, when planning the treatment program of the patients, not only hand exercises but also exercises involving the wrist should be taken into consideration.

Can We Target Close Therapeutic Goals in the Gait Re-Education Algorithm for Stroke Patients at the Beginning of the Rehabilitation Process?

(1) Background: The study aimed to determine the most important activities of the knee joints related to gait re-education in patients in the subacute period after a stroke. We focused on the tests that a physiotherapist could perform in daily clinical practice. (2) Methods: Twenty-nine stroke patients (SG) and 29 healthy volunteers (CG) were included in the study. The patients underwent the 5-meter walk test (5mWT) and the Timed Up and Go test (TUG). Tests such as step up, step down, squat, step forward, and joint position sense test (JPS) were also performed, and the subjects were assessed using wireless motion sensors. (3) Results: We observed significant differences in the time needed to complete the 5mWT and TUG tests between groups. The results obtained in the JPS show a significant difference between the paretic and the non-paretic limbs compared to the CG group. A significantly smaller range of knee joint flexion (ROM) was observed in the paretic limb compared to the non-paretic and control limbs in the step down test and between the paretic and non-paretic limbs in the step forward test. (4) Conclusions: The described functional tests are useful in assessing a stroke patient's motor skills and can be performed in daily clinical practice.

Acute effects of Nordic hamstring exercise on hip and knee joints proprioception.

BACKGROUND AND OBJECTIVES: Nordic Hamstring Exercise (NHE) is one of the best exercises proposed for injury prevention of hamstring muscles. However, its effects on lower extremity proprioception are unclear. The aim of this study was to investigate the immediate effects of a single bout of NHE on hip and knee joints' proprioception. METHODS: Forty collegiate male soccer players participated in this study with a mean age of 22.85 ± 1.82 years and were randomized into either control (n = 20) or experimental (n = 20) groups. Each subject participated in pre-test measurements in which hip and knee active joints position sense (JPS) were assessed in standing and lying tasks using the image-capturing method. The experimental group then performed three sets of NHE with 10 repetitions in each set, while the control group rested for 10 min. Paired and independent t-tests were used for calculating the differences within and between groups on SPSS software, respectively. The level of significance was P ≤ 0.05. RESULTS: Hip JPS in the lying task and knee JPS in both of the standing and lying tasks were impaired significantly after performing a single bout of NHE (P ≤ 0.05). However, the effects of this exercise on hip JPS in the standing task were not significant (P ≥ 0.05). CONCLUSIONS: NHE performing with three sets of 10 repetitions can significantly impair hip and knee JPS immediately after exercise and reduce the proprioception acuity of the lower limbs. It is recommended to perform this exercise at a time rather than before training or match sessions.

Impaired Perception of Body-Weight Distribution Marks Functional Mobility Problems in Patients Undergoing Total Hip Arthroplasty.

Hip osteoarthritis and total hip arthroplasty imply damaged articular and periarticular structures responsible for proprioception, and this damage may impair the accurate perception of body-weight distribution. In this study, we investigated proprioceptive abilities and accuracy perceiving body-weight distribution in patients undergoing total hip arthroplasty, and we assessed the associations between these abilities and body perception accuracy with functional mobility testing in 20 patients scheduled for total hip arthroplasty and 20 age-matched healthy participants. We assessed (a) absolute error in hip joint position sense (AE-JPS), (b) absolute error in body-weight distribution (AE-BWD) during standing and sit-to-stand tasks with open and closed eyes, and (c) functional mobility with the Timed Up and Go Test (TUG). We assessed patients undergoing hip arthroplasty before (T0) and five days after their surgery (T1), while control participants underwent a single evaluation. Relative to controls, participants undergoing surgery showed higher AE-JPS at 15° of hip flexion at T0 (p = .003) and at T1 (p = .007), greater AE-BWD during sit-to-stand with open eyes at T1 (p = .014) and with closed eyes at both T0 (p = .014) and at T1 (p < .001), and worse TUG at both T0 (p = .009) and T1 (p < .001). AE-BWD during sit-to-stand with closed eyes positively correlated with TUG at T0 (r = 0.55, p = .011) and at T1 (r = 0.51, p = .027). These findings suggested that impairments in body-weight distribution perception were evident both before and immediately after total hip arthroplasty, suggesting that these impairments may regularly mark these patients' functional mobility problems.

Influence of compression garments on proprioception: A systematic review and meta-analysis.

Compression garments (CGs) are commonly used in rehabilitation and sports contexts to enhance performance and speed up recovery. Despite the growing use of CGs in recent decades, there is no unanimous consensus on their overall influence on joint proprioception. In this current meta-analysis, we aim to fill this knowledge gap by assessing the impact of CGs on joint proprioception. We conducted a literature search across seven databases and one registry. Ultimately, we included 27 studies with 671 participants. The meta-analysis revealed that wearing CGs resulted in a significant reduction in absolute error during joint position sensing (Hedges' g: -0.64, p = 0.006) as compared to no CGs. However, further analyses of variables such as constant error (p = 0.308), variable error (p = 0.541) during joint position sense tests, threshold to detect passive motion (p = 0.757), and active movement extent discrimination (p = 0.842) did not show a significant impact of CGs. The review also identified gaps in the reporting of certain outcomes, such as parameters of CGs, reporting of performance, individual-reported outcomes, and lack of placebo comparators. Consequently, this review provides guidelines for future studies that may facilitate evidence-based synthesis and ultimately contribute to a better understanding of the overall influence of CGs on joint proprioception.

The efficacy of taping on elbow proprioception in healthy individuals: A single-blinded randomized placebo-controlled study.

BACKGROUND: Taping stimulates the mechanoreceptors, increases sensory information to the central nervous system, and improves sensorimotor synchronization, resulting in improved motor control. However, the efficacy of taping on elbow proprioception is not clear. PURPOSE: This study aimed to evaluate the immediate effects of taping on elbow proprioception in healthy individuals. STUDY DESIGN: This study was a two-arm, parallel-group, randomized, controlled, single-blinded study with a sham application. METHODS: Fifty six healthy adults were randomized 1:1 to kinesio taping (n = 27) or sham taping (n = 29). Active joint position sense error (JPSE) was used to quantify proprioception using a universal goniometer at three-time points: baseline (BS), immediately after taping (IA), and 30 minutes after taping (30MA), with the tape still in place at 70° and 110° of elbow flexion. Participants were blinded to group assignments. The Friedman analysis assessed differences between evaluations within groups, and the Mann-Whitney U test determined differences between groups. RESULTS: The study was completed with 56 participants and there were no dropouts. No skin reaction or adverse effect was observed in the participants and no test trial was excluded. The baseline scores of the groups were similar (p > 0.05). A significant difference was detected in the study group after kinesio taping at 70° (MD = -1.22; CI = (-2.33: -0.10; p < 0.005; d = 0.653) and 110° of elbow flexion (MD = -1.34; CI = 2,47: -0,21; p < 0.005; d = 0.73). This statistically significant difference was observed even at the 30MA evaluations at 70° (p < 0.05). Also, there was a statistically insignificant tendency to decrease in JPSE of both groups at both degrees following taping. CONCLUSIONS: Elbow proprioception may be enhanced by kinesio taping, and this effect could last up to 30 minutes at 70° of elbow flexion. In contrast, sham taping did not produce such an improvement. Based on the differences in JPSE, kinesio taping proved more effective and had a longer-lasting impact than the sham application. The statistically insignificant tendency to decrease in JPSE may indicate that the 30-minute application period is inadequate to create a statistically significant effect on elbow proprioception. Longer usage periods can better reveal the effects of orthoses on proprioception.

Does backward gait require more proprioception and balance in older adults after total knee arthroplasty?

Objectives: Some basic and instrumental daily living activities include backward gait. There is a need to clarify which parameters should be focused more on to improve backward gait in older individuals. This research investigated the proprioception, and balance in forward-backward gait of older individuals with total knee arthroplasty (TKA). Methods: A prospective cross-sectional research was conducted with 105 older adults with TKA. Individuals' forward and backward gait performance was assessed with the Timed Up & Go Test (TUG) and 3 Meter Walk Back Test (3MBWT), respectively. Proprioception was measured with a mobile application-based inclinometer. Berg Balance Scale (BBS) and Activity Specific Balance Confidence Scale (ABC) were used to assess balance and balance confidence levels, respectively. A single clinician evaluated the individuals. Results: TUG was weakly and positively correlated with the Right and Left Leg Proprioception Test (RLPT and LLPT) (r1 = 0.386, r2 = 0.391, p < 0.01). Also, the 3MBWT was weakly and positively correlated with RLPT and LLPT, respectively (r1 = 0.293, r2 = 0.251, p < 0.01). In addition, TUG was strongly and negatively correlated with BBS and ABC, respectively (r1 = -0,693, r2 = -0.722, p < 0.01). Besides, 3MBWT was strongly and negatively correlated with BBS and ABC (r1 = -0.642, r2 = -0.645, p < 0.01). Conclusion: The study revealed that forward and backward walking were similarly associated with balance and proprioception in older adults with TKA. Clinicians should focus more on balance ability than proprioception to improve backward walking performance in older individuals with THA.

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.

Effect of Kinesio taping on wrist proprioception in healthy subjects: A randomized clinical trial.

BACKGROUND: Although the use of KT has increased considerably in the clinical practice in the last years, there is limited evidence about the effects of its application in proprioception. PURPOSE: The aim of this study was to determine the effect of KT on joint position sense and force sense on the wrist of healthy subjects. METHODS: Fifty-four subjects were analyzed in a randomized, crossover, single-blind study design. To determine the force sense, the subjects had to reach 50% of their maximum grip force. Wrist joint position sense was assessed during active repositioning tests at the target angles of 30° flexion and extension of wrist. A digital dynamometer was used to determine the sense of force and a digital goniometer was used to determine the joint position sense. Subjects were evaluated with KT (I- strip on ventral aspect of forearms from origin to insertion) and placebo (an inelastic tape was applied following the same procedure as KT). RESULTS: No significant differences have been found in the force sense, neither in the comparisons between control and interventions (p=0.286), nor between pre and post-intervention (p=0.111). For wrist joint position sense, a statistically significant effect (p< 0.05) was found at 30º of extension between the control and experimental group in favor of the control group. CONCLUSIONS: The application of KT did not produce changes in FS and only caused a significant improvement in JPS in extension (30º). The results appear to indicate that the application of KT to improve proprioception in healthy subjects should be reconsidered.

Joint position sense testing at the wrist and its correlations with kinesiophobia and pain intensity in individuals who have sustained a distal radius fracture: A cross-sectional study.

BACKGROUND: Sensorimotor impairment following distal radius fracture (DRF) has been associated with a significant decline in function. Joint position sense (JPS) testing is a meaningful and responsive way to assess sensorimotor impairment for individuals who have sustained a DRF; however, there are factors that may influence the results of JPS testing, including kinesiophobia and pain intensity. PURPOSE: This study aimed to evaluate the influence kinesiophobia may have on wrist JPS testing and if pain intensity impacts kinesiophobia and JPS in individuals with a DRF. STUDY DESIGN: This was a cross-sectional study. METHODS: Participants referred from two medical centers with a diagnosis of DRF treated with at least 3 weeks of immobilization were enrolled in the study. Data were collected at 1 week and 6 weeks postimmobilization period. Demographics were summarized with descriptive statistics, and linear relationships between kinesiophobia, pain intensity, and wrist JPS were examined using Pearson correlation coefficient. RESULTS: Forty-eight participants were included in this study (mean age 42.9 years). Significant positive correlations were found between the Tampa Scale for Kinesiophobia (TSK) and Numeric Rating Scale (NRS; r = 0.951, p < 0.001), TSK and JPS error (r = 0.942, p < 0.001), as well as NRS and JPS error (r = 0.898, p < 0.001). These correlations indicate that higher levels of kinesiophobia are associated with increased pain intensity and greater JPS error. T-tests reveal no significant difference between male and female for the TSK, NRS, or JPS scores. CONCLUSIONS: There is an association for individuals with high levels of kinesiophobia and both greater pain and errors with JPS testing.

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

BACKGROUND: Individuals with rotator cuff-related shoulder pain (RCRSP) have altered proprioception. The relationship between shoulder pain and proprioception is not well understood. PURPOSE: This study aimed to investigate the relationship between shoulder pain and proprioception. STUDY DESIGN: This was a cross-sectional comparative study. METHODS: Twenty-two participants with RCRSP (mean age 27.6 ± 4.8 years) and 22 matched pain-free participants (23.4 ± 2.5 years) performed two upper limb active joint position sense tests: (1) the Upper Limb Proprioception Reaching Test (PRO-Reach; reaching toward seven targets) in centimeters and (2) Biodex System at 90% of maximum internal rotation in degrees. Participants performed three memorization and three reproduction trials blindfolded. The proprioception error (PE) is the difference between the memorized and estimation trials. Pain levels were captured pre- and post-evaluation (11-point Likert Numerical Pain Rating Scale). Relationships between PE and pain were investigated using independent t-tests and Spearman rank correlations. RESULTS: Overall, 22.7% RCRSP participants indicated an increase in pain following the PRO-Reach (X̅ increase of 1.4 ± 1.5 points), while 59% did so with the Biodex (X̅ increase of 2.3 ± 1.8 points), reflecting a clinically important increase in pain. Weak-to-moderate correlations between pain and PEs were found with the Biodex (r = 0.39-0.53) and weak correlations with the PRO-Reach (r = -0.26 to 0.38). Concerning PEs, no significant differences were found between groups with the Biodex (p = 0.32, effect size d = -0.31 [-0.90 to 0.29]). The RCRSP participants demonstrated lower PEs with the PRO-Reach in elevation compared to pain-free participants (global X̅ = 4.6 ± 1.2 cm vs 5.5 ± 1.5 cm; superior 3.8 ± 2.1 cm vs 5.7 ± 2.9 cm; superior-lateral nondominant targets 4.3 ± 2.2 cm vs 6.1 ± 2.8 cm; p = 0.02-0.05, effect size d = 0.72-0.74 [0.12-1.3]). CONCLUSIONS: Individuals with RCRSP demonstrated better upper limb proprioception in elevation, suggesting a change to interoception (sensory reweighting) in the presence of pain.

Immediate effects of elbow orthoses on elbow proprioception in asymptomatic individuals: A randomized sham-controlled single-blinded study.

BACKGROUND: Improving proprioception can reduce the risk of injuries, while its disruption may lead to injuries and recurrent or persistent symptoms. PURPOSE: This study aimed to evaluate the immediate effects of elbow orthoses on elbow proprioception in asymptomatic individuals. STUDY DESIGN: This was a randomized, controlled, single-blinded study with a sham application. METHODS: Sixty participants were equally distributed into three orthosis groups (counterforce, sleeve, and sham). Proprioception was assessed using active joint position sense error (JPSE) at 70° and 110° of elbow flexion at three time points: baseline (BS), immediately after (IA) wearing the orthosis, and 30 minutes after (30MA) wearing the orthosis. RESULTS: Between groups: No significant difference in JPSE was observed at 70° (p = 0.095); however, there was a significant difference at 110° (p = 0.005). Between time points: At 70°, JPSE did not exhibit a significant difference (p = 0.055), whereas a significant difference was observed at 110° (p = 0.020). Interaction of time points×groups: No significant interaction was observed either at 70° (p = 0.476) or at 110° (p = 0.346). At 70°, within the sleeve group, significant differences were identified between BS-30MA (p = 0.001) and IA-30MA (p = 0.009). At 110°, in the sleeve group, significant differences were observed between BS-30MA (p = 0.007) and IA-30MA (p = 0.007). In the counterforce group, significant differences were identified between BS-30MA time points (p = 0.001). At 70°, no difference was observed within the overall evaluation in the counterforce group (p > 0.05), whereas at 110°, a significant difference was noted (p = 0.026). At both 70° and 110°, no differences were identified within the overall evaluation in the sleeve and sham groups (p > 0.05). CONCLUSIONS: In asymptomatic individuals, sleeve orthosis improved elbow proprioception at 70°, whereas both counterforce and sleeve orthoses were effective at 110°.

Investigation of Reaction Time, Proprioception, and Shaped Pathway Walking Performance in Older Patients with Total Knee Arthroplasty.

OBJECTIVES: The existing literature on total knee arthroplasty (TKA) does not provide clear data on step reaction time and proprioception and gait in shaped pathways. This study investigated the relationship between proprioception and reaction time with walking performance in shaped pathways in older patients undergoing TKA. DESIGN: A cross-sectional observational study. SETTING AND PARTICIPANTS: An orthopedic outpatient clinic with 103 older patients with TKA after a minimum of 6 months after surgery. METHODS: Participants were evaluated with Figure-of-8 Walk Test (F8WT), L Test, Tinnetti Gait Test (TGT), proprioception measurement with an app-based inclinometer, and step reaction time (SRT) test. The same assessor carried out all evaluations. RESULTS: F8WT showed a strong correlation with SRT-right, SRT-left, and Tinetti Gait Test (TGT), respectively (r1 = 0.628, r2 = 0.619, r3 = -0.615, P < .01). In addition, F8WT was moderately correlated with Right Leg Proprioception Test (RLPT) and Left Leg Proprioception Test (LLPT), respectively (r1 = 0.487, r2 = 0.439, P < .01). There was a moderate correlation between L Test with RLRT, LLRT, and TGT, respectively (r1 = 0.597, r2 = 0.584, r3 = -0.542, P < .01). Besides, there was a weak positive correlation between L Test with RLPT and LLPT, respectively (r1 = 0.394, r2 = 0.335, P < .01). A regression model showed that the L test was related to RLRT, LLRT, and TGT (R2 = 0.432, P < .001). The higher ability of the L test was weakly associated with higher levels of TGT (standardized ß = -0.28, P = .0012). Besides, regression analysis also proved that F8WT was related to RLRT, LLRT, and TGT (R2 = 0.522, P < .001). The most highly associated parameter was LLRT (standardized ß = 0.958, P = .003). CONCLUSIONS AND IMPLICATIONS: Gait in shaped pathways is associated with proprioception, reaction time, and balance ability in older patients with TKA. Therefore, proprioception, reaction time, and balance should be considered to improve the shaped pathway walking performance of patients after bilateral, right, or left TKA surgery.

Handball players have superior shoulder proprioception: a prospective controlled study.

BACKGROUND: Proper proprioceptive and neuromuscular control is crucial for the overhead athlete's performance. The aim of the present study was to evaluate the shoulder joint position sense (JPS) levels in overhead throwing athletes. The secondary aim was to confront the proprioceptive abilities with glenohumeral adaptive changes and pathologies among athletes. METHODS: Ninety professional handball players and 32 healthy volunteers were recruited. JPS levels were measured by an electronic goniometer and expressed as values of an active reproduction of the joint position (ARJP) and as error of ARJP (EARJP) in 3 different reference positions for each movement (abduction and flexion at 60°, 90°, and 120°; internal [IR] and external rotation [ER] at 30°, 45°, and 60°). RESULTS: Side-to-side differences revealed significantly better values of EARJP for the throwing shoulders in abduction at 90° and 120°, flexion at 90° and 120°, IR at 60°, and ER at 30° and 60° compared with the nonthrowing shoulders. Handball players showed significantly better proprioceptive levels in their throwing shoulder compared to the dominant shoulder of the control group in abduction at 90° (P = .037) and 120° (P = .001), flexion at 120° (P = .035), IR at 60° (P = .045), and in ER at 60° (P = .012). DISCUSSION: Handball players present superior shoulder JPS in their dominant throwing shoulder at high range of motion angles when compared to a nonathlete population and to their own nondominant shoulder.

Reference value of knee position sense in weight-bearing and non-weight-bearing conditions.

BACKGROUND: Our study aimed to identify age-related changes in knee proprioception to provide reference values for weight-bearing (WB) and non-weight-bearing (NWB) conditions and to identify factors (age, WB condition, dominance, and sex) that can affect knee proprioception. METHODS: A total of 84 healthy adult men and women were recruited. Active knee joint position sense (JPS) was measured using a digital inclinometer for knee proprioception. The participants performed the required movements actively, with verbal feedback from the examiner, slowly moving to the target angles (30° and 50°) and maintaining them for 5 s before returning to the starting position. Afterward, without assistance from the examiner, the participants actively moved back to the same angle, and the examiner confirmed the angles. This procedure was repeated twice for each target angle, and the average values were used as the data. The participants were barefoot, wearing shorts, and closed their eyes while the measurements were obtained. The measurements were first obtained on the dominant side under the NWB conditions. When a change in posture was needed during the measurement, the participants sat in a resting position for 2 min. RESULTS: Except for age, all other factors (WB condition, dominance, sex) were not statistically significant. Age showed a significant difference in knee JPS, except for the non-dominant side at 30° and the dominant side at 50° in the NWB condition. CONCLUSION: This study indicates that the WB condition, dominant side, and sex need not be considered when measuring and assessing knee JPS. Age shows a negative correlation with knee joint position sense, and the reference values presented in this study can be used as objective target values during the rehabilitation process.

Acute effects of isotonic eccentric exercise on the neuromuscular function of knee extensors vary according to the motor task: impact on muscle strength profiles, proprioception and balance.

Introduction: Eccentric exercise has often been reported to result in muscle damage, limiting the muscle potential to produce force. However, understanding whether these adverse consequences extend to a broader, functional level is of apparently less concern. In this study, we address this issue by investigating the acute and delayed effects of supramaximal isotonic eccentric exercise on neuromuscular function and motor performance of knee extensors during tasks involving a range of strength profiles, proprioception, and balance. Methods: Fifteen healthy volunteers (23.2 ± 2.9 years old) performed a unilateral isotonic eccentric exercise of the knee extensors of their dominant lower limb (4 × 10 reps at 120% of one Repetition Maximum (1RM)). The maximum voluntary isometric contraction (MVC), rate of force development (RFD), force steadiness of the knee extensors, as well as knee joint position sense and mediolateral (MLI) and anteroposterior stability (API) of the dominant lower limb, were measured pre-, immediately, and 24 h after the eccentric exercise. The EMG amplitude of the vastus medialis (VM) and biceps femoris (BF) were concomitantly evaluated. Results: MVC decreased by 17.9% immediately after exercise (P < 0.001) and remained reduced by 13.6% 24 h following exercise (P < 0.001). Maximum RFD decreased by 20.4% immediately after exercise (P < 0.001) and remained reduced by 15.5% at 24 h (P < 0.001). During the MVC, EMG amplitude of the VM increased immediately after exercise while decreasing during the RFD task. Both values returned to baseline 24 h after exercise. Compared to baseline, force steadiness during submaximal isometric tasks reduced immediately after exercise, and it was accompanied by an increase in the EMG amplitude of the VM. MLI and knee joint position sense were impaired immediately after isotonic eccentric exercise (P < 0.05). While MLI returned to baseline values 24 h later, the absolute error in the knee repositioning task did not. Discussion: Impairments in force production tasks, particularly during fast contractions and in the knee joint position sense, persisted 24 h after maximal isotonic eccentric training, revealing that neuromuscular functional outputs were affected by muscle fatigue and muscle damage. Conversely, force fluctuation and stability during the balance tasks were only affected by muscle fatigue since fully recovered was observed 24 h following isotonic eccentric exercise.

Test-retest reliability of joint position sense in the elbow among healthy adults.

BACKGROUND: Proprioception of the elbow is necessary for daily activities. Proprioception can be impaired with injury or pathology, and rehabilitation efforts seek to improve proprioception for improved upper extremity functioning. In clinical practice, joint position sense (JPS) testing is often utilized to assess conscious proprioception; however, varying methods exist with little evidence of psychometric properties, especially for the elbow. PURPOSE: The primary aim of this study was to create a standardized elbow JPS test protocol using goniometry measurement to determine the most reliable testing position. The secondary aim was to determine if the elbow JPS test had acceptable test-retest reliability in healthy adults. STUDY DESIGN: This was a cross-sectional study using a convenience sample of healthy adults. METHODS: Three elbow positions (45°, 60°, and 75° of elbow flexion) were measured twice on the same day by a single rater using a universal goniometer. We calculated the absolute error in degrees between each position and reposition and the intraclass correlation coefficient (3,1) for relative reliability. We also calculated the standard error of the measurement and visually inspected Bland-Altman plots for absolute reliability. RESULTS: Sixty-eight healthy adults (mean age 27.9 years, standard deviation 8.59) were assessed. The mean absolute error for all positions for test and retest was 5.7°. The intraclass correlation coefficients were moderate to good (0.57-0.75), and the standard error of the measurement was 2° (rounded) for all positions. The limits of agreement were moderately narrow, and the Bland-Altman plots showed a random distribution of errors for each position, indicating clinically acceptable measurement error. CONCLUSIONS: The joint position reproduction test for JPS using goniometry demonstrated moderate to good test-retest reliability and acceptable measurement error in healthy adults. The elbow joint angle of 60° flexion was the most reliable for JPS testing, providing insight for JPS assessment in clinical practice.

Exercise-induced fatigue affects knee proprioceptive acuity and quadriceps neuromuscular function more in patients with ACL reconstruction or meniscus surgery than in healthy individuals.

PURPOSE: To observe how knee proprioceptive acuity and quadriceps neuromuscular function change during and after repeated isokinetic knee-extension exercise in patients with anterior cruciate ligament reconstruction (ACLR) or meniscus surgery. METHODS: Patients with ACLR or meniscus surgery and matched controls (n = 19 in each group) performed knee-flexion replication at 15° and 75°, and quadriceps peak torque (PT), central activation ratio (CAR) and rate of torque development (RTD) at baseline and immediately after every five sets of isokinetic knee-extension exercise (times 1-5). RESULTS: Compared to the baseline, the ACLR and control groups displayed errors in knee-flexion replication at 75° only at time 5 (115.9-155.6%; p ≤ 0.04, d ≥ 0.97), whereas the meniscus surgery group exhibited errors at all time points (142.5-265.6%; p ≤ 0.0003, d ≥ 1.4). Significant percentage reductions in quadriceps CAR were observed between times 4 and 5 in the ACLR group (-5.8%; p = 0.0002, d = 0.96), but not in the meniscus surgery (-1.4%; n.s.) and control (0.1%; n.s.) groups. Significant percentage reductions in quadriceps RTD were observed between times 4 and 5 in the ACLR (-24.2%; p = 0.007, d = 0.99) and meniscus surgery (-23.0%; p = 0.01, d = 0.85) groups, but not in the control group (-0.2%; n.s.). CONCLUSION: Patients with ACLR or meniscus surgery displayed a greater loss in knee proprioceptive acuity and quadriceps neuromuscular function during and after exercise than healthy individuals. Evidence-based interventions to enhance exercise-induced fatigue resistance should be implemented following ACLR or meniscus surgery, aiming to prevent proprioceptive and neuromuscular changes within the knee joint and quadriceps. LEVEL OF EVIDENCE: III.