Proprioceptive accuracy in women with early and established knee osteoarthritis and its relation to functional ability, postural control, and muscle strength

Balance Control is Sequentially Correlated with Proprioception, Joint Range of Motion, Strength, Pain, and Plantar Tactile Sensation Among Older Adults with Knee Osteoarthritis

BACKGROUND

Patients with knee osteoarthritis (KOA) are at high risk for falls, which is attributed to their impaired balance control. Identifying factors associated with balance control facilitates the development of precise KOA rehabilitation programs. This study was to investigate the correlations of balance control with proprioception, plantar tactile sensation (PTS), pain, joint range of motion (ROM), and strength among older adults with and without KOA, as well as the magnitudes and sequence of correlation of these factors to balance control.

METHODS

A total of 240 older adults with (n = 124, female: 84, age: 68.8 ± 4.0 years) and without (n = 116, female: 64, age: 67.9 ± 3.5 years) KOA were recruited and assigned to the KOA and control groups. Their proprioception, PTS, pain, ROM, and strength were measured. Pearson or Spearman correlations were used to test whether they were significantly related to their Berg Balance Scale (BBS), and factor analysis and multivariate linear regression were used to determine the degrees of correlation between each factor and the BBS.

RESULTS

Compared to the control group, the KOA group had lower BBS score, larger proprioception and PTS thresholds, smaller ROM, and less strength (p: 0.008, < 0.001-0.016, < 0.001-0.005, < 0.001-0.014, and < 0.001-0.002, respectively). In the KOA group, the BBS was weakly to moderately correlated with proprioception, PTS, pain, ROM, and strength (r: 0.332-0.501, 0.197-0.291, 0.340, 0.212-0.508, and 0.236-0.336, respectively). While in the control group, the BBS was correlated with proprioception and strength (r: 0.207-0.379, and 0.212-0.410). In the KOA group, BBS = 54.41+ (0.668*strength) - (0.579*PTS) - (1.141*proprioception) + (1.054* ROM) - (0.339*pain). While in the control group, BBS = 53.85+ (0.441*strength) - (0.677*proprioception).

CONCLUSION

Worse proprioception and PTS, smaller ROM, and less strength were detected among older adults with KOA, and their proprioception, PTS, pain, ROM, and strength were all related to balance control. Proprioception had the strongest correlations, followed by ROM, strength, pain, and PTS. Precise KOA rehabilitation programs may be proposed following the sequence of improving the five factors.

Postural stability and its relation to knee flexor/extensor strength ratio in women with mild to moderate unilateral knee osteoarthritis: a case-control study

PURPOSE/AIM

Knee muscles strength is an important factor influencing postural stability in patients with knee osteoarthritis (KOA). However, there is no evidence regarding the relationship between the knee flexor/extensor strength ratio, which is suggested to be a good indicator of knee stability, and postural stability. We aimed to investigate postural stability and its relation to knee flexor and extensor strength and strength symmetry in women with KOA.

MATERIALS AND METHODS

Thirty-five women with unilateral KOA and thirty-five asymptomatic women were assessed with the Prokin system to collect the following parameters during quiet standing with eyes-open and eyes-closed: ellipse area, perimeter, forward-backward standard deviation, mediolateral standard deviation, the average centre of pressure displacement on the x- and y-axises (COPX and COPY), and the limit of stability (LoS) score. Higher scores mean better balance for LoS and poorer balance for other parameters. Knee flexor and extensor strength were assessed bilaterally with the Lafayette hand-held dynamometer.

RESULTS

The COPX during standing with eyes-closed was higher in women with KOA than controls and the LoS score was lower (p < 0.05, Cohens'd = 0.72 and 0.65). Postural stability was correlated with knee muscles strength and the flexor/extensor strength ratios in both groups (r = between 0.395 and 0.456 for LoS, r = between -0.335 and -0.639 for the others, p < 0.05).

CONCLUSIONS

Women with KOA had poorer postural stability in the mediolateral direction during standing with eyes-closed and a worse LoS score than controls. Postural stability was related to knee flexor and extensor strength and the flexor/extensor strength ratio in women.

Effects of mind-body exercise on knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effect of mind-body exercise on improving knee osteoarthritis (KOA) and thereby informing osteoarthritis exercise rehabilitation.

METHODS

The China National Knowledge Infrastructure (CNKI), Wanfang, PubMed/Medline, Cochrane Library, Web of Science, EBSCO, Embase, Scopus, and ProQuest databases were searched to identify randomized controlled trials (RCTs) that involved tai chi, yoga, and baduanjin interventions for KOA. The search period ranged from inception to October 25, 2022. The methodological quality of the included studies was evaluated by the Cochrane risk of bias assessment tool, and the included data were statistically analyzed and plotted using Review Manager 5.3 and Stata 14.0 software.

RESULTS

We included 17 articles with a total of 1122 patients. Compared with the control group, mind-body exercise significantly improved patient pain (standardized mean difference (SMD) = -0.65, 95% confidence interval (CI) [-0.87, -0.42], p < 0.00001), stiffness (SMD = -0.75, 95% CI [-1.05, -0.45], p < 0.00001), physical function (SMD = -0.82, 95% CI [-1.03, -0.62], p < 0.00001), mental health (SMD = 0.31, 95% CI [0.11, 0.51], p = 0.002), and depression (SMD = -0.32, 95% CI [-0.50, -0.15], p = 0.0003). In terms of motor ability, mind-body exercise significantly increased the 6-min walking distance (SMD = 18.45, 95% CI [5.80, 31.10], p = 0.004) and decreased timed up and go test time (SMD = -1.15, 95% CI [-1.71, -0.59], p < 0.0001).

CONCLUSIONS

The current study showed that mind-body exercise is safe and effective for KOA patients. However, given the methodological limitations of the included studies, additional high-quality evidence is needed to support the conclusions of this study.

Association between quadriceps tendon elasticity and neuromuscular control in individuals with knee osteoarthritis

BACKGROUND

Knee osteoarthritis is a complex condition with established risk factors such as female sex, increasing age and body mass index, reduced quadriceps muscle strength and knee injury. Despite known associated risks, the role and behaviour of knee tendons in knee osteoarthritis remains unclear. This study explores the association between quadriceps tendon elasticity, muscle strength, neuromuscular control, proprioception and patient reported outcome measures in individuals with knee osteoarthritis.

METHODS

Adults with doctor-diagnosed knee osteoarthritis were recruited from rheumatology clinics and general practitioner practices. Quadriceps tendon elasticity was estimated using sonoelastography. Neuromuscular control data including electromyography, electromechanical delay and proprioception measures were included. Participants completed the Knee Injury and Osteoarthritis Outcome Score. Associations between elasticity values, physical and neuromuscular data and patient reported outcomes scores were evaluated using Spearman's correlations.

FINDINGS

Thirty-nine adults with knee osteoarthritis were eligible for inclusion. Increased tendon stiffness was negatively associated with rate of force development, time to half peak force and passive positioning sense in individuals with knee osteoarthritis. Similarly, patient reported symptoms were found to be associated with sonoelastography findings with moderate-strong associations observed between activities of daily living sport and recreation, pain and symptoms and between neuromuscular control measures and muscle strength.

INTERPRETATION

Stiffer tendon identified within the knee osteoarthritis group was associated with reduced neuromuscular control and knee joint proprioception. Stiffer quadriceps tendon may contribute to the poorer reported symptoms by knee osteoarthritis individuals. These findings may impact disease symptoms and progression which could lead to further joint impairment.

Evaluation of Knee Position Sense in Children with Motor Disabilities and Children with Typical Development: A Cross-Sectional Study

BACKGROUND

In children with motor disabilities, knee position during walking is often of concern in rehabilitation. This study aimed to investigate knee joint position sense. Thirty-seven children with Cerebral Palsy (CP), 21 with Myelomeningocele (MMC), 19 with Arthrogryposis (AMC), and 42 TD children participated in the study. Knee joint position sense, i.e., the difference between the criterion angle and the reproduced angle (JPS-error), was assessed in sitting while 3D motion capture was recorded at flexed knee 70 (Knee70), 45 (Knee45), and 20 (Knee20) degrees, and after three seconds at maintained criterion angle (CAM) and maintained reproduced angle (RAM). No differences were found between the groups in JPS-error, CAM, and RAM. At Knee70, CAM differed between the right and left legs in the TD group (p = 0.014) and RAM in the MMC group (p = 0.021). In the CP group, CAM was greater than RAM at Knee70 in the left leg (p = 0.002), at Knee45 in both legs (p = 0.004, p = 0.025), and at Knee20 in the right leg (p = 0.038). Difficulties in maintaining the knee position at CAM in the CP group sheds light on the need for complementary judgments of limb proprioception in space to explore the potential influence on knee position during walking.

Functional manifestations of early knee osteoarthritis: a systematic review and meta-analysis

Early detection of knee osteoarthritis (KOA) can improve treatment outcomes and prevent its progression. The aim of this systematic review was to identify the functional changes in early KOA. Electronic journal databases and platforms, including PubMed, the Physiotherapy Evidence Database, the Cochrane Central Register of Controlled Trials, and Scopus were searched. The inclusion criteria were as follows: (1) studies comparing patients with early KOA with an age-matched control group and (2) studies with objectively measured functional changes as outcomes. Studies that included individuals with Kellgren and Lawrence (K/L) grades > 2- were excluded. A random-effects model was constructed to calculate pooled standardized mean differences (SMDs). A total of nine articles were included in this systematic review. Seven studies used classification criteria to define early KOA, including knee pain; a K/L grade of 0, 1, or 2- (osteophytes only) for the medial compartment; and the presence of two out of four MRI criteria. The remaining two studies included K/L grade 1 confirmed by radiography. Early KOA participants had a significantly longer timed up-and-go test (TUG) time (pooled SMD: 0.57; 95% confidence interval: 0.15, 0.98). The two groups had similar knee extension muscle strength at 90° knee flexion. The quality of evidence for each measured outcome was "very low." In this review, longer TUG was identified as a functional manifestation of early KOA. Further studies involving functional assessments are needed to develop a screening method to detect early KOA. Key Points • There is a need for diagnostic criteria that include functional changes in patients with early knee osteoarthritis, since radiographic facilities are not available everywhere. • In this review, a long timed up-and-go test time was identified as a functional manifestation of early knee osteoarthritis. • If the findings of this study can be replicated, measurement of TUG may allow for earlier detection of knee osteoarthritis outside the hospital and in routine clinical practice without the use of MRI or X-rays.

The effects of total knee arthroplasty on knee proprioception of patients with knee osteoarthritis: a meta-analysis

BACKGROUND

Studies have given some pieces of evidence for the effect of total knee arthroplasty (TKA) on knee proprioception of patients with knee osteoarthritis (KOA), but their results were conflicting. This review was performed to provide an updated evidence-based meta-analysis investigating the influence of TKA on knee proprioception.

METHODS

The electronic databases including PubMed, Google Scholar, and the Cochrane Library were accessed from their inception to March 2020. Two reviewers identified the studies that met the selection criteria for this review. Information on study type, participants, follow-up time, and outcome measures was extracted. Methodological quality was independently assessed by two reviewers using the Cochrane Handbook 5.1.0. Eleven studies with 475 participants were included in the meta-analysis.

RESULTS

The I² index assessed the heterogeneity between studies. The results showed that the pooled standard mean difference of mean angle of error was - 0.58° (95% CI - 1 to - 0.16; P = 0.007; I² = 69%), and the joint position sense of KOA patients was better after TKA surgery than that before surgery. Pooled standard mean difference of displacement of center of pressure (COP) was - 0.39 (95% CI - 0.72 to - 0.06; P = 0.02; I² = 51%), and KOA patients had better static balance after TKA surgery than before surgery.

CONCLUSIONS

To conclude, no standardized comprehensive evaluation protocol presently exists though different assessment tools are available to measure proprioception. Contrasting results were found in the literature since some studies found that TKA improves proprioception in KOA patients, while others found no difference in proprioception. These differences are seen whether the proprioception was assessed by joint position sense (JPS), or it was indirectly assessed by static balance. However, the lack of sufficient data on the threshold to detect passive movement (TTDPM) and dynamic balance made it difficult to draw a conclusion about whether or not the sense of motion improved after surgery. The method for measuring and evaluating knee joint force sense is worth paying attention, which will make progress with knee proprioception on TKA patients.

The Effect of Proprioception Training on Pain Intensity in Thumb Basal Joint Osteoarthritis: A Randomized Controlled Trial

A randomized controlled trial of forty-five females over 18 years of age with diagnosis of thumb basal osteoarthritis in their dominant hand and with a minimum pain rating of 4/10 on the Visual Analogue Scale (VAS) during activities of daily living (ADLs) were recruited from March to June 2021. The group receiving proprioception training was compared to routine conservative physiotherapy treatment. The main purpose of this clinical trial is to test the effect of proprioception training on pain intensity in subjects with thumb osteoarthritis. Primary outcome was joint position sense (JPS) for the assessment of CMC proprioception and secondary outcomes were Visual Analogue Scale (VAS) and Canadian Occupational Performance Measure (COPM) for the assessment of patient satisfaction and the Quick-DASH which assessed upper limb function. A block randomization was carried out for the control group (n = 22) and experimental group (n = 23). Participants and evaluator were blinded to the group assignment. Proprioception training produced a statistically significant reduction in pain post intervention, but this reduction was small (d = 0.1) at the 3-month follow-up. JPS accuracy demonstrated statistically significant differences between the groups (p = 0.001) post-intervention and at the 3-month follow-up (p < 0.003). Statistically significant differences between means were found in both the Quick-Dash and COPM post intervention (both, p < 0.001), as well as at the 3-month follow-up (both, p < 0.001). There was a significant time factor for the reduction of pain intensity over time but effect sizes between groups was small at the 3-month follow-up period. Proprioceptive training improves thumb JPS accuracy; however, it does not contribute to a reduction in pain intensity in the long term. The inclusion of a proprioceptive program may be beneficial for improving individuals with thumb CMC OA sensorimotor performance. The study was registered at ClinicalTrials.gov NCT04738201. No funding was provided for this study.

The effect of self-reported knee instability on plantar pressure and postural sways in women with knee osteoarthritis

BACKGROUND

Giving way and knee instability are common problems in patients with knee osteoarthritis, disrupting the daily activities and balance of the affected individual. The present study aimed to evaluate the postural control status of women with knee osteoarthritis with and without self-report knee instability (KI).

METHODS

This cross-sectional, single-blind study was conducted on 57 female patients with knee osteoarthritis. The patients were selected based on the inclusion and exclusion criteria and divided into two groups of with KI (n = 26) and without KI (n = 31). Fear of movement was assessed using the Tampa questionnaire, the degree of knee instability was measured based on the Fitzgard scale, the static and dynamic balance of the subjects were evaluated with open and closed eyes using a Biodex balance device, and foot pressure distribution situation was measured using a FDM-S-Zebris device.

RESULTS

Mean comparison showed a significant difference between the subjects with and without KI in static balance only in anterior-posterior direction with open eyes (p = 0.01) and closed eyes (p = 0.0001). In the dynamic balance test, the subjects in both groups had significant differences in terms of all the indicators of anterior-posterior stability (p = 0.001), medial-lateral stability (p = 0.0001), and overall stability (p = 0.0001) with closed eyes. However, no significant difference was observed with open eyes (p > 0.05). Multiple regression also indicated significant positive correlations between pain intensity and disease duration with the degree of KI (p < 0.05).

CONCLUSIONS

According to the results, there were significant differences between the mean pain scores, static and dynamic balance, and the rate of fall between the women with knee osteoarthritis with and without the KI index. Therefore, patients with knee osteoarthritis, which also has an index of KI, are more susceptible to falls, and proper strategies are required to reduce the level of KI in these patients.

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.

Examining the Use of Kinesiology Tape During Weight Bearing Exercises on Proprioception in Participants With Functional Ankle Instability

The aim of this study was to examine the effect of tape worn during weight bearing exercises on proprioception (i.e., ankle angle repositioning error) in participants with functional ankle instability. We employed a randomized, controlled clinical study in a laboratory setting, with 56 participants with functional ankle instability. Participants were randomly assigned to three groups: (a) weight bearing exercises without tape (n = 18), (b) weight bearing exercises with tape (n = 19) and controls not engaged in weight bearing exercises (n = 19). Weight bearing exercises included six weeks of bilateral squats in partial form with up to 45 degrees of knee flexion, and unilateral partial squats with full heel raise, and with full toe raise. In the taped condition, participants wore tape for six weeks with up to three tape replacements per week. Proprioception was measured as ankle repositioning error. Results showed that the mean angle repositioning error among participants in the active weight bearing groups was decreased by the taping intervention, relative to the control group's performance (p = 0.042). There were no significant differences between weight bearing exercise groups and control groups. The addition of kinesiology tape in weight bearing exercises can improve proprioception in active conditions.

Is Thumb Proprioception Decreased in Patients With Trapeziometacarpal Joint Osteoarthritis?

Proprioception is thought to be essential for normal joint homeostasis, and its decreased function has been associated with an increased risk of joint diseases. However, only a few studies have been performed on the association between proprioceptive function in the trapeziometacarpal joint (TMCJ) and osteoarthritis. The purpose of this study was to compare TMCJ proprioceptive function in elderly women with radiographic TMCJ osteoarthritis relative to age-matched control women without osteoarthritis. We enrolled 19 women (mean age, 66 years) with symptomatic, radiographic Eaton and Littler grade 2, 3, and 4 TMCJ osteoarthritis and 19 age-matched control women without osteoarthritis. We evaluated thumb proprioception by using a joint-position reproduction test and compared the reposition error (RE) between the groups. We carried out a multivariate analysis for factors potentially associated with increased RE, such as age, body mass index, hand dominance, the presence of diabetes, pain level, and the presence of osteoarthritis. Also, a logistic regression analysis was performed for factors associated with the occurrence of TMCJ osteoarthritis. Patients with TMCJ osteoarthritis had greater RE than did the control patients in the joint-position reproduction test at 20°, 30°, and 40° of thumb palmar abduction. The multivariate analysis indicated that increased RE was associated with the presence of osteoarthritis, but not with the other factors assessed. The occurrence of TMCJ osteoarthritis was associated with increased RE at 20°, 30°, and 40° of thumb palmar abduction. This study showed that decreased proprioceptive function was associated with the presence of osteoarthritis in the TMCJ, although the causality remains unknown. Further studies on the role of proprioception in the pathogenesis of TMCJ osteoarthritis and the potential role of its training for disease prevention or treatment are required.

Comparison of proprioception between osteoarthritic and age-matched unaffected knees: a systematic review and meta-analysis

PURPOSE

Theoretically, proprioceptive acuity could decrease in patients with knee osteoarthritis. However, there have been conflicting results in terms of proprioceptive deficit in osteoarthritic knees. The purpose of this systematic review and meta-analysis was to compare knee proprioception between osteoarthritic and healthy control knees.

METHODS

Studies comparing proprioception in osteoarthritic and healthy knees of age-matched control group using thresholds to detect passive motion (TTDPM) or joint position sense (JPS) tests were identified. JPS was assessed by measuring the reproduction of passive positioning (RPP) or active positioning (RAP) of the knees.

RESULTS

Seventeen studies were finally included in this meta-analysis. The pooled results of the analyses of the TTDPM for both 30° and 45° knee flexion showed that the mean angle of error was 0.83° greater (95% confidence interval: 0.44 to 1.23°; p < 0.001) in the osteoarthritic knees than in control knees. The pooled data of the RAP and RPP also showed that the mean angle of error was 1.89° greater in the osteoarthritic knees than in the control group. The mean difference in the angle of error between the osteoarthritic knees and control group was 1.06° greater in the JPS test than in the TTDPM (p < 0.001).

CONCLUSION

The knee proprioceptive acuity of the patients with knee osteoarthritis was poorer than that of the patients with unaffected knees in the age-matched control group both in terms of the TTDPM and JPS; clinical relevance of these deficits needs to be clarified in further studies.

LEVEL OF EVIDENCE

Meta-analysis, Level II.

Wireless Motion Sensors-Useful in Assessing the Effectiveness of Physiotherapeutic Methods Used in Patients with Knee Osteoarthritis-Preliminary Report

Osteoarthritis of the knee (OAK) is characterized by pain, limitation of joint mobility, and significant deterioration of proprioception resulting in functional decline. This study assessed proprioception in OAK patients following two ten-day rehabilitation programs using the Orthyo® system. Fifty-four study participants with clinical symptoms and radiological signs of OAK were randomly divided into an exercise group (n = 27) or a manual therapy group (n = 27). The control group consisted of 27 volunteers with radiological signs of OAK, but with no clinical symptoms or prior history of rehabilitation. The following parameters were assessed: knee proprioception using inertial sensors and a mobile application, patients' function using Western Ontario and McMaster Universities osteoarthritis index (WOMAC), and pain intensity using the visual analog scale (VAS). Following rehabilitation, knee proprioception tests did not improve in either study group. Both study groups showed significant improvement of the WOMAC-assessed function (exercise group: p < 0.01, manual therapy group: p = 0.01) and a significant decrease (p < 0.01) of VAS-assessed pain following rehabilitation, but the post-therapy results did not differ significantly between the aforementioned groups. The Orthyo® system provided a quick and accurate assessment of the knee joint position sense. There was no direct relationship between functionality, pain, and proprioception threshold in the knee joint.

Lower extremity proprioceptive sensation in patients with early stage knee osteoarthritis: A comparative study

BACKGROUND

Knee OA causes pain and proprioceptive impairment. The body acts as a closed kinetic chain, and deformation on the knee cannot only affect the knee joint but also can affect the other joints.

OBJECTIVE

To assess the proprioception of lower extremity in early stage knee osteoarthritis compared with without knee osteoarthritis individuals.

METHODS

The study sample consisted of 26 adults with early stage knee osteoarthritis and 26 subjects without knee osteoarthritis individuals. Western Ontario and McMaster Universities Osteoarthritis Index was used for clinical disease severity. Visual Analogue Scale was used for pain severity. Proprioception (position and motion sense) was measured by isokinetic dynamometer.

RESULTS

Western Ontario and McMaster Universities Osteoarthritis Index total score was 10.9 ± 5. Visual Analogue Scale scores during activity were found to be significantly higher than the scores at rest and night for both sides. Hip flexion and internal rotation joint position sense were significantly different between two groups (all p's < 0.05). Hip abduction, knee flexion, ankle and subtalar position sense, as well as hip and knee motion sense were similar between groups (all p's > 0.05). Ankle dorsiflexion and eversion motion sense were significantly different between two groups (all p's < 0.05).

CONCLUSIONS

This study demonstrated that the hip flexion and internal rotation position sense and ankle/subtalar joints motion sense may be affected on early stage of knee osteoarthritis. Investigation of the mechanism of proprioception for joints and also focusing on the longitudinal relationship between proprioception, knee OA disease and symptoms is recommended for future studies.

Relative difference in muscle strength between patients with knee osteoarthritis and healthy controls when tested bilaterally and joint-inclusive: an exploratory cross-sectional study

Background

To improve the goal-directedness of strength exercises for patients with knee osteoarthritis (KOA), physical rehabilitation specialists need to know which muscle-groups are most substantially weakened across the kinetic chain of both lower extremities. The purpose was to improve the knowledge base for strength exercise therapy. The objective was to explore the relative differences in muscle strength in the main directions bilaterally across the hip, knee, and ankle joints between patients with light-to-moderate symptomatic and radiographic KOA and people without knee complaints.

Methods

The design was an exploratory, patient vs. healthy control, and cross-sectional study in primary/secondary care. Twenty-eight patients with mild to moderate KOA (18 females, mean age 61) and 31 matched healthy participants (16 females, mean age 55), participated. Peak strength was tested concentrically or isometrically in all main directions for the hip, knee, and ankle joints bilaterally, and compared between groups. Strength was measured by a Biodex Dynamometer or a Commander II Muscle Tester (Hand-Held Dynamometer). Effect sizes (ES) as Cohen’s d were applied to scale and rank the difference in strength measures between the groups. Adjustment for age was performed by analysis of covariance.

Results

The most substantial muscle weaknesses were found for ankle eversion and hip external and internal rotation in the involved leg in the KOA-group compared to the control-group (ES [95% CI] −0.73 [−1.26,-0.20], − 0.74 [−1.26,-0.21], −0.71 [−1.24,-0.19], respectively; p < 0.01). Additionally, smaller but still significant moderate muscle weaknesses were indicated in four joint–strength directions: the involved leg’s ankle inversion, ankle plantar flexion, and knee extension, as well as the uninvolved leg’s ankle dorsal flexion (p < 0.05). There was no significant difference for 17 of 24 tests.

Conclusions

For patients with KOA between 45 and 70 years old, these explorative findings indicate the most substantial weaknesses of the involved leg to be in ankle and hip muscles with main actions in the frontal and transverse plane in the kinetic chain of importance during gait. Slightly less substantial, they also indicate important weakness of the knee extensor muscles. Confirmatory studies are needed to further validate these exploratory findings.

Effects of knee orthoses on kinesthetic awareness and balance in healthy individuals

Introduction

Conflicting evidence exists regarding the effects of knee orthoses on proprioception. One belief is that pressure applied by orthoses heightens kinesthetic awareness and that this affects balance. This study aimed to investigate the effects of two different orthosis designs on kinesthetic awareness and balance in healthy individuals.

Methods

Twenty individuals (13 women) participated in this case series study. Each was tested wearing 1/no orthosis, 2/soft elastic orthosis and 3/non-elastic jointed orthosis. Pressure under orthoses was recorded. Kinesthetic awareness was investigated by testing joint position sense and threshold to detection of passive motion. Balance was tested using a modified sensory organization test.

Results

Non-elastic jointed orthoses applied the greatest pressure to the knee. With non-elastic jointed orthoses, threshold to detection of passive motion was significantly poorer for pooled results (p = 0.02) and when the start position of the knee was 70° (mean threshold = 0.6°, 0.6°, 0.7° for no-orthosis, elastic and jointed-orthoses; p = 0.03). No major differences were observed in JPS or balance and correlation between proprioception and balance was poor.

Conclusions

There may be a limit to the amount of pressure that should be applied to the knee joint by an orthosis. Exceeding this limit may compromise kinesthetic awareness.

How proprioception changes before and after total knee arthroplasty: A systematic review

BACKGROUND

Proprioception is one of the most significant factors in balance, joint stability, graceful movement, coordination, and injury prevention. It involves a wide set of receptors located within joints, muscles, and tendons. Given the neurophysiological processes involved in proprioception response are multiple and complex, there is not one single method to measure it. Particularly, proprioception of the knee joint, whether it is healthy, affected by osteoarthritis, or after replacement, is the most investigated by in literature.

RESEARCH QUESTION

This review addresses the analysis of proprioception in the knee joint before and after total knee arthroplasty (TKA). The aim is to obtain an overview of the proprioceptive skills in subjects who suffered from osteoarthritis and were subjected to knee replacement, evaluating changes in proprioception before and after the surgery.

METHODS

The research was conducted within four databases: Web of Science®, PubMed Central®, Cochrane®, and PEDro®, between January 2008 and February 2018. Accurate exclusion criteria and selection strategy were applied to screen the 170 articles found.

RESULTS

Ultimately, 13 papers were fully evaluated and included in this review, divided into two classes: i) works directly measuring proprioception, ii) studies indirectly evaluating proprioception. Contrasting results emerged from the analysis, and no consensus was found in the literature about the improvement or worsening in proprioception before and after TKA.

SIGNIFICANCE

Since currently there is high variability in methods, protocol and parameters used to evaluate knee proprioception, further investigations based on a consistent dataset, a well-defined protocol, measurable outcomes, timeline follow-ups, and rehabilitation programs should be performed in order to obtain reliable results on the effects of TKA on knee proprioception and balance.

The effects of toe-out and toe-in postures on static & dynamic balance, risk of fall and TUG score in healthy adults

BACKGROUND

Toe-in and toe-out foot positions have not yet been tested for dynamic balance and risk of fall. The aim of this study was to investigate the effects of these two modifications on static and dynamic postural stability and risk of fall through instrumental (Biodex Balance System^®) and functional (timed up and go-TUG test) tools.

METHODOLOGY

Twenty healthy adults (8 males, 12 females, age: 29±4.10years, BMI: 21.56±2.36kg/m²) participated in this study. Static and dynamic (levels 8 and 2) balance with single stance and double stance and dynamic (level 8 and levels 6-2) for risk of fall with double stance were tested with the Biodex Balance System with three self-selected feet positions: straight (13.8°), toe-out (35.6°) and toe-in (-11.9°) for each test condition. Additionally, TUG test was performed with toe-out and toe-in gait.

RESULTS

The results of repeated measures ANOVA showed significant differences (p<0.05) between straight and modified toe angles in balance at dynamic level 2 with both double and single stance conditions. Significant differences (p<0.001) were also found in TUG scores for the test conditions.

CONCLUSION

Toe-in and toe-out gait modifications have significant effects on balance at higher levels of platform tilt and functional balance. Further investigations with knee osteoarthritis patients and electromyography may provide insight in balancing strategies adopted by the body in toe-out and toe-in gait.

Postoperative Treatment of Distal Radius Fractures Using Sensorimotor Rehabilitation

Background  Sensorimotor and specifically proprioception sense has been used in rehabilitation to treat neurological and joint injuries. These feedback loops are not well understood or implemented in wrist treatment. We observed a temporary sensorimotor loss, following distal radius fractures (DRF) that should be addressed postsurgery. Purpose  The purpose of this prospective therapeutic study was to compare the outcomes of patients following surgery for DRF treated using a sensorimotor treatment protocol with those patients treated according to the postoperative standard of care. Patients and Methods  Patients following surgery for DRF sent for hand therapy were eligible for the study. Both the evaluation and treatment protocols included a comprehensive sensorimotor panel. Patients were randomized into standard and standard plus sensorimotor postoperative therapy and were evaluated a few days following surgery, at 6 weeks, and 3 months postsurgery. Results  Sixty patients following surgery were randomized into the two treatment regimens. The initial evaluation was similar for both groups and both demonstrated significant sensorimotor deficits, following surgery for DRF. There was documented sensorimotor and functional improvement in both groups with treatment. The clinical results were better in the group treated with the sensorimotor-proprioception protocol mostly in the wrist; however, not all of the differences were significant. Conclusion  Patients after surgery for DRF demonstrate significant sensorimotor deficits which may improve faster when utilizing a comprehensive sensorimotor treatment protocol. However, we did not demonstrate efficacy of the protocol in treating proprioceptive deficits. Further study should include refinement of functional outcome evaluation, studying of the treatment protocol, and establishment of sensorimotor therapeutic guidelines for other conditions. Level of Evidence This is a level II, therapeutic study.

Towards secondary prevention of early knee osteoarthritis

Osteoarthritis (OA) of the knee is the most common arthritic disease, yet a convincing drug treatment is not available. The current narrative review focuses on integration of scientific evidence and professional experience to illustrate which management approaches can be taken for prototypical individual patient profiles with early knee OA. Animal models suggest that: (1) OA can progress even in the presence of fully recovered movement kinetics, kinematics and muscle activation patterns; (2) muscle weakness is an independent risk factor for the onset and possibly the rate of progression of knee OA; (3) onset and progression of OA are not related to body weight but appear to depend on the percentage of body fat. From studies in the human model, one could postulate that risk factors associated with progression of knee OA include genetic traits, preceding traumatic events, obesity, intensity of pain at baseline, static and dynamic joint malalignment and reduced muscle strength. Taken this into account, an individual can be identified as early knee OA at high risk for disease progression. A holistic patient-tailored management including education, supportive medication, weight loss, exercise therapy (aerobic, strengthening and neuromuscular) and behavioural approaches to improve self-management of early knee OA is discussed in individual prototypic patients. Secondary prevention of early knee OA provides a window of opportunity to slow down or even reverse the disease process. Yet, as the sheer number of patients early in the OA disease process is probably large, a more structured approach is needed to provide appropriate care depending on the patient's individual risk profile.

Association of malalignment, muscular dysfunction, proprioception, laxity and abnormal joint loading with tibiofemoral knee osteoarthritis - a systematic review and meta-analysis

Background

To investigate (1) the association of specific biomechanical factors with knee osteoarthritis and knee osteoarthritis development, and (2) the impact of other relevant risk factors on this association.

Methods

MEDLINE, EMBASE, CINAHL and SPORTDiscus were searched up until April 2017. Studies were included if they fulfilled the following criteria: the study 1) assessed the association of a biomechanical factor with knee osteoarthritis, or knee osteoarthritis development; 2) reported on skeletal malalignment, muscular dysfunction, impaired proprioception, laxity and abnormal loading during gait; 3) was a cohort study with participants developing knee osteoarthritis and participants not developing knee osteoarthritis, or a case-control or cross-sectional study with participants with knee osteoarthritis and without knee osteoarthritis. Risk of bias was assessed with the QUIPS tool and meta-analyses were performed using random effects models.

Results

Of 6413 unique studies identified, 59 cross-sectional studies were eligible for meta-analyses (9825 participants, 5328 with knee osteoarthritis). No cohort studies fulfilled the inclusion criteria. Compared with healthy controls, patients with knee osteoarthritis have higher odds of having lower muscle strength, proprioception deficits, more medial varus-valgus laxity and less lateral varus-valgus laxity. Patients with medial knee osteoarthritis have higher odds of having a higher knee adduction moment than healthy controls. Level of evidence was graded as ‘very low’ to ‘moderate’ quality. Due to large between study differences moderation of other risk factors on biomechanical risk factors could not be evaluated.

Conclusions

Patients with knee osteoarthritis are more likely to display a number of biomechanical characteristics. The causal relationship between specific biomechanical factors and the development of knee osteoarthritis could not be determined as no longitudinal studies were included. There is an urgent need for high quality, longitudinal studies to evaluate the impact of specific biomechanical factors on the development of knee osteoarthritis.

Trial Registration

(PROSPERO ID: CRD42015025092).

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2202-8) contains supplementary material, which is available to authorized users.

Inter- and intrarater reliability of two proprioception tests using clinical applicable measurement tools in subjects with and without knee osteoarthritis

BACKGROUND

The therapeutic value of proprioceptive-based exercises in knee osteoarthritis (KOA) management warrants investigation of proprioceptive testing methods easily accessible in clinical practice.

OBJECTIVE

To estimate inter- and intrarater reliability of the knee joint position sense (KJPS) test and knee force sense (KFS) test in subjects with and without KOA.

DESIGN

Cross-sectional test-retest design.

METHOD

Two blinded raters performed independently repeated measures of the KJPS and KFS test, using an analogue inclinometer and handheld dynamometer, respectively, in eight KOA patients (12 symptomatic knees) and 26 healthy controls (52 asymptomatic knees). Intraclass correlation coefficients (ICCs; model 2,1), standard error of measurement (SEM) and minimal detectable change with 95% confidence bounds (MDC₉₅) were calculated.

RESULTS

For KJPS, results showed good to excellent test-retest agreement (ICCs 0.70-0.95 in KOA patients; ICCs 0.65-0.85 in healthy controls). A 2° measurement error (SEM 1°) was reported when measuring KJPS in multiple test positions and calculating mean repositioning error. Testing KOA patients pre and post therapy a repositioning error larger than 4° (MDC₉₅) is needed to consider true change. Measuring KFS using handheld dynamometry showed poor to fair interrater and poor to excellent intrarater reliability in subjects with and without KOA.

CONCLUSIONS

Measuring KJPS in multiple test positions using an analogue inclinometer and calculating mean repositioning error is reliable and can be used in clinical practice. We do not recommend the use of the KFS test to clinicians. Further research is required to establish diagnostic accuracy and validity of our KJPS test in larger knee pain populations.

Toward classification criteria for early osteoarthritis of the knee

OBJECTIVE

To propose draft classification criteria for early stage osteoarthritis (OA) of the knee for use in a primary care setting.

METHODS

A group of basic scientists, physician-scientists, rheumatologists, orthopedic surgeons, and physiotherapists in a workshop setting discussed potential classification criteria for early osteoarthritis of the knee. The workshop was divided into sessions around relevant topics with short state of the art presentations followed by breakout sessions, consensus discussions, and consolidation into a consensus document.

RESULTS

Three classes of criteria were agreed: (1) Pain, symptoms/signs, self-reported function, and quality of life using tools such as KOOS: scoring ≤85% in at least 2 out of these 4 categories; (2) Clinical examination: at least 1 present out of joint line tenderness or crepitus; (3) Knee radiographs: Kellgren & Lawrence (KL) grade of 0 or 1. MRI is at present not recommended as an aid to identify or define early OA in routine clinical practice or primary care, in light of the absence of validated consensus criteria and the high population prevalence of structural joint changes detected by this method. Biomarkers may have future utility in early OA classification, but no individual or set of biomarkers is yet robust enough.

CONCLUSION

Based on our consensus proposal, draft classification criteria for early OA of the knee for use in clinical studies should include patient reported outcomes such as pain and function, together with clinical signs and KL grade 0-1 on radiographs.

Effects of strength exercise on the knee and ankle proprioception of individuals with knee osteoarthritis

This study aims to investigate the effects of 8-week strength exercise on knee and ankle proprioception of individuals with knee osteoarthritis (KOA). Forty participants were randomly divided into control and strength exercise groups. Strength exercise group underwent squat training of three times a week for 8 weeks, while control group received an education programme. Threshold for detection of passive movement of knee and ankle joint was tested using an electrically driven movable frame. Between- and within-group differences were evaluated through repeated-measurement analysis of variance. After intervention, passive motion sense in knee flexion of participants in strength exercise group significantly improved (p = 0.033, 95% confidence interval of mean difference: 0.019-1.478) with significant difference between groups. No significant differences of passive motion senses were found in knee extension and ankle between strength exercise and control groups. Eight-week squat training significantly improves the motion sense of knee flexion in patients with KOA.

Effects of different foot progression angles and platform settings on postural stability and fall risk in healthy and medial knee osteoarthritic adults

This study aims to investigate the effects of varying toe angles at different platform settings on Overall Stability Index of postural stability and fall risk using Biodex Balance System in healthy participants and medial knee osteoarthritis patients. Biodex Balance System was employed to measure postural stability and fall risk at different foot progression angles (ranging from -20° to 40°, with 10° increments) on 20 healthy (control group) and 20 knee osteoarthritis patients (osteoarthritis group) randomly (age: 59.50 ± 7.33 years and 61.50 ± 8.63 years; body mass: 69.95 ± 9.86 kg and 70.45 ± 8.80 kg). Platform settings used were (1) static, (2) postural stability dynamic level 8 (PS8), (3) fall risk levels 12 to 8 (FR12) and (4) fall risk levels 8 to 2 (FR8). Data from the tests were analysed using three-way mixed repeated measures analysis of variance. The participant group, platform settings and toe angles all had a significant main effect on balance ( p ≤ 0.02). Platform settings had a significant interaction effect with participant group F(3, 144) = 6.97, p < 0.01 and toe angles F(21, 798) = 2.83, p < 0.01. Non-significant interactions were found for group × toe angles, F(7, 266) = 0.89, p = 0.50, and for group × toe angles × settings, F(21, 798) = 1.07, p = 0.36. The medial knee osteoarthritis group has a poorer postural stability and increased fall risk as compared to the healthy group. Changing platform settings has a more pronounced effect on balance in knee osteoarthritis group than in healthy participants. Changing toe angles produced similar effects in both the participant groups, with decreased stability and increased fall risk at extreme toe-in and toe-out angles.

Changes in gait characteristics of women with early and established medial knee osteoarthritis: Results from a 2-years longitudinal study

BACKGROUND

Despite the large number of cross-sectional studies on gait in subjects with knee osteoarthritis, there are scarcely any longitudinal studies on gait changes in knee osteoarthritis.

METHODS

Gait analysis was performed on 25 women with early and 18 with established medial knee osteoarthritis, as well as a group of 23 healthy controls. Subjects were asked to walk at their comfortable speed. Kinematic and kinetic data were measured at baseline and after 2years follow-up.

FINDINGS

Results indicated that the early osteoarthritis group, similar to established osteoarthritis group, showed significantly higher maximum knee adduction angles compared to the controls during the early stance phase of gait. None of the kinematic or kinetic measures, changed over two years in the early osteoarthritis group. In the established osteoarthritis group, at the time of entry, an increased first and second peak knee adduction moment, as well as higher mid-stance knee adduction moment and knee adduction moment impulse, were present compared to the control and the early osteoarthritis groups. Mid-stance knee adduction moment and knee adduction moment impulse, further increased over two years only in the established osteoarthritis group. For all three groups, the peak knee flexion angle during the stance phase decreased significantly over time.

INTERPRETATION

Increased maximum knee adduction angle during stance phase was the only alteration in the gait pattern of subjects with early knee osteoarthritis compared to the controls. This suggests that, unlike in the later stages of the disease, gait is rather stable over two years in early osteoarthritis.

Medial knee loading is altered in subjects with early osteoarthritis during gait but not during step-up-and-over task

This study evaluates knee joint loading during gait and step-up-and-over tasks in control subjects, subjects with early knee OA and those with established knee OA. Thirty-seven subjects with varying degrees of medial compartment knee OA severity (eighteen with early OA and sixteen with established OA), and nineteen healthy controls performed gait and step-up-and-over tasks. Knee joint moments, contact forces (KCF), the magnitude of contact pressures and center of pressure (CoP) location were analyzed for the three groups for both activities using a multi-body knee model with articular cartilage contact, 14 ligaments, and six degrees of freedom tibiofemoral and patellofemoral joints. During gait, the first peak of the medial KCF was significantly higher for patients with early knee OA (p = 0.048) and established knee OA (p = 0.001) compared to control subjects. Furthermore, the medial contact pressure magnitudes and CoP location were significantly different in both groups of patients compared to controls. Knee rotation moments (KRMs) and external rotation angles were significantly higher during early stance in both patient groups (p < 0.0001) compared to controls. During step-up-and-over, there was a high variability between the participants and no significant differences in KCF were observed between the groups. Knee joint loading and kinematics were found to be altered in patients with early knee OA only during gait. This is an indication that an excessive medial KCF and altered loading location, observed in these patients, is a contributor to early progression of knee OA.

[Effect of electroacupuncture on proprioception in cynomolgus monkeys after unilateral anterior cruciate ligament injury]

OBJECTIVE

To study the effect of electroacupuncture on proprioception in cynomolgus monkeys after unilateral anterior cruciate ligament (ACL) injury.

METHODS

Twenty-seven cynomolgus monkeys were randomized equally into 3 groups, namely unilateral ACL injury with electroacupuncture group, unilateral ACL injury model group and blank control group. One week after modeling, the monkeys in electroacupuncture group were treated daily for 12 weeks with electroacupuncture at the acupoints Wei Yang, Yin Gu, Xi Yangguan and Qu Quan. At 4, 8, and 12 weeks during the treatment, the changes in the somatosensory evoked potentials (SEPs) and motor nerve conduction velocity (MCV) of the nerves of the ACL were examined with neural electrophysiological method; the changes in the morphology and the total and variable number of the proprioceptors in the ACL were observed with gold chloride staining. RESULTS; In the mokeys in the model group, the incubation period of the SEPs and MCV on the injured side of the knee were significantly extended and the amplitudes were decreased with the passage of time (P<0.05). Intervention with electroacupuncture significantly reduced the incubation period and increased the amplitudes of the SEPs and MCV (P<0.05). The total number of the proprioceptors in the ACL was significantly decreased and the variable number of the proprioceptors in ACL was increased with time in the monkeys in the model group (P<0.05); electroacupuncture intervention obviously slowed the reduction rate of total number of the proprioceptors (P<0.05) but without affecting the variable number of the proprioceptors (P>0.05). CoONCLUSION: ACL injury causes attenuation of the proprioception on the injury side, and electroacupuncture intervention can produce a positive effect on the proprioception in cynomolgus monkeys.

Identification of clinical phenotypes in knee osteoarthritis: a systematic review of the literature

Background

Knee Osteoarthritis (KOA) is a heterogeneous pathology characterized by a complex and multifactorial nature. It has been hypothesised that these differences are due to the existence of underlying phenotypes representing different mechanisms of the disease.

Methods

The aim of this study is to identify the current evidence for the existence of groups of variables which point towards the existence of distinct clinical phenotypes in the KOA population. A systematic literature search in PubMed was conducted. Only original articles were selected if they aimed to identify phenotypes of patients aged 18 years or older with KOA. The methodological quality of the studies was independently assessed by two reviewers and qualitative synthesis of the evidence was performed. Strong evidence for existence of specific phenotypes was considered present if the phenotype was supported by at least two high-quality studies.

Results

A total of 24 studies were included. Through qualitative synthesis of evidence, six main sets of variables proposing the existence of six phenotypes were identified: 1) chronic pain in which central mechanisms (e.g. central sensitisation) are prominent; 2) inflammatory (high levels of inflammatory biomarkers); 3) metabolic syndrome (high prevalence of obesity, diabetes and other metabolic disturbances); 4) Bone and cartilage metabolism (alteration in local tissue metabolism); 5) mechanical overload characterised primarily by varus malalignment and medial compartment disease; and 6) minimal joint disease characterised as minor clinical symptoms with slow progression over time.

Conclusions

This study identified six distinct groups of variables which should be explored in attempts to better define clinical phenotypes in the KOA population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1286-2) contains supplementary material, which is available to authorized users.

Biomechanical and neuromuscular adaptations during the landing phase of a stepping-down task in patients with early or established knee osteoarthritis

BACKGROUND

To compare the knee joint kinematics, kinetics and EMG activity patterns during a stepping-down task in patients with knee osteoarthritis (OA) with control subjects.

METHODS

33 women with knee OA (early OA, n=14; established OA n=19) and 14 female control subjects performed a stepping-down task from a 20cm step. Knee joint kinematics, kinetics and EMG activity were recorded on the stepping-down leg during the loading phase.

RESULTS

During the stepping-down task patients with established knee OA showed greater normalized medial hamstrings activity (p=0.034) and greater vastus lateralis-medial hamstrings co-contraction (p=0.012) than controls. Greater vastus medialis-medial hamstrings co-contraction was found in patients with established OA compared to control subjects (p=0.040) and to patients with early OA (p=0.023). Self-reported knee instability was reported in 7% and 32% of the patients with early and established OA, respectively.

CONCLUSIONS

The greater EMG co-activity found in established OA might suggest a less efficient use of knee muscles or an attempt to compensate for greater knee laxity usually present in patients with established OA. In the early stage of the disease, the biomechanical and neuromuscular control of stepping-down is not altered compared to healthy controls.

Changes in proprioceptive weighting during quiet standing in women with early and established knee osteoarthritis compared to healthy controls

OBJECTIVES

Knee osteoarthritis (OA) is highly prevalent in people above the age of 60, and is typically associated with pain, stiffness, muscle weakness and proprioceptive deficits. Muscle-tendon vibration has been used to assess the spatial reweighting of proprioceptive input during standing. The current study aimed to investigate whether weighting of proprioceptive input is altered in patients with early and established knee OA compared to asymptomatic controls.

METHODS

The upright posture of 27 participants with early OA, 26 with established OA, and 27 asymptomatic controls was perturbed by vibrating (frequency: 70Hz and amplitude: approximately 0.5mm) ankle muscles (i.e. tibialis anterior and triceps surae) and knee muscles (vastus medialis). Center of pressure displacements of the participants were recorded using a force plate.

RESULTS

Both patients with early and established OA were more sensitive to triceps surae vibration compared to their healthy peers (P<0.01 for both). No such difference was found for the vibration of tibialis anterior or vastus medialis muscles between patients with knee OA and healthy controls.

CONCLUSIONS

These results suggest that the early stages of knee OA may already lead to reweighting of proprioceptive information, suggesting more reliance on ankle proprioceptive input for postural control.

Can pain influence the proprioception and the motor behavior in subjects with mild and moderate knee osteoarthritis?

Background

Osteoarthritis (OA) is a chronic disease, usually characterized by pain, which is associated with reduced muscle strength, disability and progressive loss of function. However, the pain influence over proprioception and motor behaviour remains unclear. Thus, the purpose of the study was to identify the levels of pain, the proprioceptive acuity and the pattern of muscle recruitment during stair ascent and descent in elderly patients with mild and moderate osteoarthritis (OA) compared to healthy subjects.

Methods

The study participants included 11 healthy elderly subjects (7 women and 4 men) and 31 elderly patients with knee OA (19 women and 12 men). The functional capacity was assessed by the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index; the pain was evaluated by Wong-Baker faces pain rating scale (WBS) and pressure pain threshold (PPT); the proprioceptive acuity was based on the joint position sense evaluated by electrogoniometer; and the electromyographic (EMG) activity of the major muscles of the lower limb were evaluated during a task of stair ascent and descent of 15 cm. For statistical analysis it was used Statistic for Windows software (StatSoft Inc., version 5.0). Data from the WOMAC index, WBS, the proprioceptive acuity and IEMG (for each muscle in each phase) were analyzed using the Mann–Whitney U test and data from PPT was used Kruskal-Wallis test.

Results

Higher scores were found in the WOMAC index and WBS whereas lower scores were seen in PPT in patients with knee OA compared to healthy subjects. In contrast, there were no significant differences in the proprioceptive acuity and EMG results of most muscles analyzed between the groups.

Conclusion

The presence of pain does not influence the proprioception and the motor behavior of the thigh muscles during stair ascent and descent in subjects with mild and moderate knee OA.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-321) contains supplementary material, which is available to authorized users.

Balance and gait adaptations in patients with early knee osteoarthritis

Gait adaptations in people with severe knee osteoarthritis (OA) have been well documented, with increased knee adduction moments (KAM) the most commonly reported parameter. Neuromuscular adaptations have also been reported, including reduced postural control. However these adaptations may be the result of morphological changes in the joint, rather than the cause. This study aimed to determine if people with early OA have altered gait parameters and neuromuscular adaptations. Gait and postural tasks were performed by 18 people with early medial knee OA and 18 age and gender-matched control subjects. Parameters measured were kinematics and kinetics during gait and postural tasks, and centre of pressure and electromyographic activity during postural tasks. OA subjects showed no differences in the gait parameters measured, however they demonstrated postural deficits during one-leg standing on both their affected and unaffected sides and altered hip adduction moments compared with controls. Increased activity of the gluteus medius of both sides (p<0.05), and quadriceps and hamstrings of the affected side (p<0.05) during one-leg standing compared with controls were also noted. This study has demonstrated that gait adaptations commonly associated with OA do not occur in the early stages, while neuromuscular adaptations are evident. These results may be relevant for early interventions to delay or prevent osteoarthritis in its early stages.

Balance and risk of fall in individuals with bilateral mild and moderate knee osteoarthritis

Balance is essential for mobility and performing activities of daily living. People with knee osteoarthritis display impairment in knee joint proprioception. Thus, the aim of this study was to evaluate balance and risk of fall in individuals with bilateral mild and moderate knee osteoarthritis. Sixty subjects aged between 50 and 70 years volunteered in this study. They were categorized into three groups which were healthy (n = 20), mild (n = 20) and moderate (n = 20) bilateral knee osteoarthritis groups. Dynamic and static balance and risk of fall were assessed using Biodex Stability System. In addition, Timed Up and Go test was used as a clinical test for balance. Results of this study illustrated that there were significant differences in balance (dynamic and static) and risk of fall between three groups. In addition, the main (most significant) difference was found to be between healthy group and moderate group. Furthermore, on clinical scoring of balance, the “Timed Up and Go” test, all three groups showed significant difference. In conclusion, bilateral knee osteoarthritis impaired the balance and increased the risk of fall, particularly in people with moderate knee osteoarthritis.

The Influence of Tai Chi Exercise on Proprioception in Patients with Knee Osteoarthritis: Results from a Pilot Randomized Controlled Trial

PURPOSE

Previous long-term observational studies found that Tai Chi practitioners had better knee-joint proprioceptive acuity versus controls in an older population. We evaluated the effects of Tai Chi for knee-joint proprioception in knee osteoarthritis (OA) in a randomized controlled trial.

METHODS

We randomized 40 eligible individuals (age > 55, BMI ≤ 40 kg/m2 with knee pain on most days of the previous month and tibiofemoral OA (K/L grade ≥2) to Tai Chi (10 modified forms from classical Yang style) or to an attention control (stretching and wellness education). The 60 minute intervention sessions occurred twice-weekly for 12 weeks. The knee joint proprioception was measured using a Biometrics™ electrogoniometer with an ADU301 angle display unit during each assessment visit. Three test angles (30, 45 and 60 degrees) were evaluated with each subject in a sitting position taken as neutral (0 degrees). The mean error (absolute angle error) between the actual and replicated angles was calculated for each of the three test angles. The Tai Chi and control groups were compared by intention-to-treat using t-tests.

RESULTS

The participants had a mean age of 65 y (SD 7.8), a mean disease duration of 10 y (SD 7.6), a mean BMI of 30.0 kg/m2 (SD 4.8), and median K/L grade 4; 75% were female, 70% were white. The participants in the Tai Chi intervention exhibited significantly improved proprioception at 30 degrees, but not at 45 or 60 degrees, at 12 weeks. Patients who continued Tai Chi practice after 12 weeks also reported no significant improvements in knee proprioception at 24 and 48 weeks.

CONCLUSION

Tai Chi appears to be beneficial for knee proprioception in people with severe knee OA at a 30 degree test angle immediately following 12 weeks of practice. However, we were unable to demonstrate that Tai Chi has any long-term effects on knee proprioception, nor were we able to find any effects on proprioception at larger test angles (45 and 60 degrees). Standardized and reproducible measures for knee proprioception should be explored in future research.