Chronic ankle instability is associated with proprioception deficits:A systematic review and meta-analysis

Background:Acute ankle injury causes damage to joint mechanoreceptors and deafferentation and contributes to proprioception deficits in patients with chronic ankle instability(CAI).We aimed to explore whether deficits of proprioception,including kinesthesia and joint position sense(JPS),exist in patients with CAI when compared with the uninjured contralateral side and healthy people.We hypothesized that proprioception deficits did exist in patients with CAI and that the deficits varied by test methodologies.Methods:The study was a systematic review and meta-analysis.We identified studies that compared kinesthesia or JPS in patients with CAI with the uninjured contralateral side or with healthy controls.Meta-analyses were conducted for the studies with similar test procedures,and narrative syntheses were undertaken for the rest.Results:A total of 7731 studies were identified,of which 30 were included for review.A total of 21 studies were eligible for meta-analysis.Compared with the contralateral side,patients with CAI had ankle kinesthesia deficits in inversion and plantarflexion,with a standardized mean difference(SMD)of 0.41 and 0.92,respectively,and active and passive JPS deficits in inversion(SMD=0.92 and 0.72,respectively).Compared with healthy people,patients with CAI had ankle kinesthesia deficits in inversion and eversion(SMD=0.64 and 0.76,respectively),and active JPS deficits in inversion and eversion(SMD=1.00 and 4.82,respectively).Proprioception deficits in the knee and shoulder of patients with CAI were not statistically significant.Conclusion:Proprioception,including both kinesthesia and JPS,of the injured ankle of patients with CAI was impaired,compared with the uninjured contralateral limbs and healthy people.Proprioception varied depending on different movement directions and test methodologies.The use of more detailed measurements of proprioception and interventions for restoring the deficits are recommended in the clinical management of CAI.

Age-related changes in proprioception of the ankle complex across the lifespan

Background:Ankle complex proprioceptive ability,needed in active human movement,may change from childhood to elderly adulthood;however,its development across all life stages has remained unexamined.The aim of the present study was to investigate the across-the-lifespan trend for proprioceptive ability of the ankle complex during active ankle inversion movement.Methods:The right ankles of 118 healthy right-handed participants in 6 groups were assessed:children(6-8 years old),adolescents(13-15 years old),young adults(18-25 years old),middle-aged adults(35-50 years old),old adults(60-74 years old),and very old adults(75-90 years old).While the participants were standing,their ankle complex proprioception was measured using the Active Movement Extent Discrimination Apparatus.Results:There was no significant interaction between the effects of age group and gender on ankle proprioceptive acuity(F(5,106)=0.593,p=0.705,η_p^2=0.027).Simple main effects analysis showed that there was a significant main effect for age group(F(5,106)=22.521,p<0.001,η_p^2=0.515)but no significant main effect for gender(F(1,106)=2.283,p=0.134,η_p^2=0.021)between the female(0.723±0.092,mean±SD)and the male(0.712±0.083)participants.The age-group factor was associated with a significant linear downward trend in scores(F(1,106)=10.584,p=0.002,η_p^2=0.091)and a strong quadratic trend component(F(1,106)=100.701,p<0.001,η_p^2=0.480),producing an asymmetric inverted-U function.Conclusion:The test method of the Active Movement Extent Discrimination Apparatus is sensitive to age differences in ankle complex proprioception.For proprioception of the ankle complex,young adults had significantly better scores than children,adolescents,old adults,and very old adults.The middle-aged group had levels of ankle proprioceptive acuity similar to those of the young adults.The scores for males and females were not significantly different.Examination of the range of the scores in each age group highlights the possible level that ankle complex movement proprioceptive rehabilitation can reach,especially for those 75-90 years of age.

Effect of vision loss on plasticity of the head and neck proprioception

AIM:To investigate whether head and neck proprioception and motor control could be compensatory enhanced by long-term vision loss or impairment.METHODS:Individuals who were blind,low vision or sighted were included in the study,which would undergo the head repositioning test(HRT).The constant error(CE),absolute error(AE),variable error(VE)and root mean square error(RMSE)of each subject were statistically analyzed.Data were analyzed using the SAS 9.4.Tukey-Kramer for one-way ANOVA was used for comparison of blind,low vision,and sighted subjects,as well as to compare subjects with balanced vision,strong vision in the left eye and strong vision in the right eye.Independent sample t-test was used to compare subjects with congenital blindness and acquired blindness,as well as left and right hand dominance subjects.RESULTS:A total of 90 individuals(25 blind subjects,31 low vision subjects,and 34 sighted subjects)were included in the study.Among the blind subjects,14 cases had congenital blindness and 11 cases had acquired blindness.Among the blind and low vision subjects,21 cases had balanced binocular vision,17 cases had strong vision in the left eye and 18 cases had strong vision in the right eye.Among all subjects,11 cases were left hand dominance,and 79 cases were right hand dominance.There were significant differences in AE,VE,and RMSE in head rotation between blind,low vision,and sighted subjects(P<0.01),in AE,VE,and RMSE between blind and sighted(P<0.01),and in VE and RMSE between low vision and sighted(P<0.05).No significant difference between blind and low vision(P>0.05).Significant differences in CE and AE of head right rotation and CE of general head rotation between congenital and acquired(P<0.05).No significant differences between left and right hand dominance and in balance or not of binocular vision(P>0.05).CONCLUSION:Long-term vision loss or impairment does not lead to compensatory enhancement of head and neck proprioception and motor control.Acquired experience contributes to HRT performance in the blind and has long-lasting effects on plasticity in the development of proprioception and sensorimotor control.

Correlation analysis of national elite Chinese male table tennis players’ shoulder proprioception and muscle strength

BACKGROUND Shoulder is the most injured part in table tennis players,and it takes multiple roles in transmitting power and striking the center of the ball during the stroke.Proprioception is strongly correlated with high level of athletic performance.It is customary to assume that there is a correlation between proprioception and muscle strength and therefore proprioceptive assessment and rehabilitation is often neglected.AIM To investigate the correlation between isokinetic muscle strength and proprioception in the internal and external rotation muscle groups of elite Chinese male table tennis players,to provide reference for physical training and rehabilitation of elite table tennis players.METHODS A total of 19 national elite table tennis players from the Chinese National Table Tennis Team were recruited in this research.All of them had more than 10 years training experience and had participated major competitions such as the National Games and World Youth Championships.IsoMed 2000 was used to test the peak torque of internal and external rotation isokinetic concentric contraction of the athletes'bilateral shoulder joints at low speed(60°/s)and high speed(180°/s)respectively;IsoMed 2000 was used to conduct the Joint Position Reproduction test to evaluate the athletes'proprioceptive ability capacity at low speed(60°/s)and high speed(180°/s)respectively.If the data satisfied the normal distribution,the correlation between the differences in peak torque s and angles in different directions was analyzed using a Pearson simple linear model;otherwise,Spearman correlation analysis was used.The comparison of proprioceptive ability between the table tennis racket-holding hand and non-racket-holding hands was performed using independent samples t-test if the data satisfied a normal distribution;otherwise,the Mann-Whitney U test was used.RESULTS There was no direct linear correlation between the strength and proprioceptive correlation analysis at slow speed(60°/s)and fast speed(180°/s)in the racket-holding hand;At the slow speed(60°/s)and fast speed(180°/s),there was no correlation between muscle strength and proprioception in the non-racket-holding hand except for the internal rotation variable error(VE)and external rotation relative peak torque,which showed a moderate positive correlation(r=0.477,P<0.05),(r=0.554,P<0.05).The internal rotation’s constant error(CE)and VE were 1.06±3.99 and 2.94±2.16,respectively,for the racket-holding hand,and-3.36±2.39 and 1.22±0.93,respectively,for the non-racket-holding hand;the internal rotation’s CE,VE of the racket-holding hand was lower than that of the non-racket-holding hand,and there was a highly significant difference(P<0.01).CONCLUSION There was no correlation between muscle strength and proprioceptive function in the internal and external rotation of the racket-holding hand’s shoulder in elite Chinese male table tennis players.These results may be useful for interventions for shoulder injuries and for the inclusion of proprioceptive training in rehabilitation programs.

Effect of posterior root amputation on rabbit knee joint cartilage and proprioception

Objective:To Observe the characteristics of changes in the cartilage of the rabbit's knee joint after spinal nerve transection,as well as the influence of proprioceptors and proprioceptive pathways,and explore the relationship between proprioception disorder and knee osteoarthritis.Methods:According to the principle of random allocation,20 New Zealand white rabbits were divided into groups,9 in the control group and 11 in the model group.In the model group,the posterior roots of the L5-L6 spinal nerve were cut off using the posterior root cutting method,while the control group only cut the skin and paraspinal muscles.8 weeks after the operation,the modified Tarlov scoring standard was used to evaluate the behavioral differences between the two groups of rabbits,and electrophysiology-SEPs(Somatosensory Evoked Potentials)and EMG(Surface Electromyography)were used to evaluate proprioception and muscle contraction.After the test was completed,it was unified They were sacrificed and performed HE staining.Mankin's score was used to evaluate the pathological conditions of the knee articular cartilage in the two groups.The anterior cruciate ligament(ACL)of the right knee was taken and the Bielschowsky nerve staining method was used to observe the number of proprioceptors in the two groups.Results:8 weeks after the operation,the hind limbs of the model group showed a light stroke posture,and the motor function basically returned to normal.Compared with the control group,there was no significant difference in behavioral changes(P>0.05);the model group rabbits SEPs and EMG were compared with the control group Compared with the prolonged incubation period,the amplitude decreased,and the difference was statistically significant(P<0.05).The rabbit articular cartilage surface of the model group was rough or even disappeared,and the cell arrangement was disordered.The Mankin's score was significantly higher than that of the control group(P<0.01),and cartilage damage was more severe.Compared with the control group,the number of proprioceptors in the model group was significantly reduced,the morphology changed,and the ligament tissue was loose and constricted.The difference was statistically significant(P<0.01);the rabbit chondrocytes in the model group were over-apopted and the rate of apoptosis It was significantly higher than the control group(P<0.01).Conclusion:The transection of the spinal nerve can lead to loss of proprioception,excessive apoptosis of chondrocytes,degeneration of articular cartilage,and promotion of the occurrence and development of knee osteoarthritis.

Analysis of Proprioception of Hip Joint in Total Hip Arthroplasty

Introduction: The instability of the joint is classified roughly into mechanical and functional. It is reported that the postoperative dislocation often occurs by the posterior approach of the THA and may be caused by functionality instability due to the injury of the periarticular soft tissue. We analyzed the joint position sense of the hip according to an approach of the THA and examined effect to give postoperative dislocation. Materials & Methods: 92 patients (184 hip joints) who received THA in our hospital were selected in the study. Cases in which position sensation measurements were insufficient were excluded. As for the classification, the posterior approach (PL groups) was 39 hips, anterolateral approach (AL groups) was 30 hips, and control group was 37 hips. Results: There was no significant difference between the AL group and PL group in the absolute reproduction angle error score (ARAES). The relative reproduction angle error scores (RRAES) for passive internal and external rotations and active internal rotation were significantly lower in the AL and control groups than the PL group. Discussion: This study was suggested that the hip joint position sense in the AL group was better retained for the preservation of the soft tissue.

Hybrid Static-dynamic Sensation Electrotactile Feedback for Hand Prosthesis Tactile and Proprioception Feedback

Tactile and proprioception feedback are essential to myoelectric hand prostheses control for regaining functionality of lost hands of amputees.Current studies focus on tactile feedback,while the lack of appropriate multisensory feedback,especially proprioception feedback,limits the grasping quality.Additionally,a typical non-invasive stimulation scheme for sensation feedback uses stimulation on the stationary site of the skin continuously,which can lead to fatigue and adaptation of sensation,further reduces the feedback consistency,and increases the cognitive burden for the subject.Considering the sensitivity and modality matching of sensation,this study presented a multimodal sensations feedback scheme based on hybrid static-dynamic sensation elicited by multisite Transcutaneous Electrical Nerve Stimulation(TENS)to deliver grasping force and joint position feedback.In the proposed scheme,stimulation of single electrode produced only in-loco tactile sensation under the electrode,and the sensation intensity was adjusted according to grasping force;sequential activation of multi-electrodes produced an illusion dynamic sensation of a stimulus moving,and the velocity and direction of movement were adjusted according to finger joint position.Psychometric test results demonstrated the identifiability of stimulus in the proposed scheme.Further,prosthetic hand closed-loop grasping tasks evaluate the effectiveness of the proposed feedback scheme.The results showed that the proposed feedback scheme could substantially improve the grasping accuracy and efficiency.In addition,the study outcomes also demonstrated the benefit of artificial proprioception feedback in grasping rapidity and security.

The measurement of proprioceptive accuracy:A systematic literature review

Background:Proprioceptive accuracy refers to the individual’s ability to perceive proprioceptive information,that is,the information referring to the actual state of the locomotor system,which originates from mechanoreceptors located in various parts of the locomotor system and from tactile receptors located in the skin.Proprioceptive accuracy appears to be an important aspect in the evaluation of sensorimotor functioning;however,no widely accepted standard assessment exists.In this systematic review,our goal was to identify and categorize different methods that are used to assess different aspects of proprioceptive accuracy.Methods:A literature search was conducted in 5 different databases(PubMed,SPORTDiscus,PsycINFO,ScienceDirect,and SpringerLink).Results:Overall,1139 scientific papers reporting 1346 methods were included in this review.The methods assess 8 different aspects of proprioception:(a)the perception of joint position,(b)movement and movement extent,(c)trajectory,(d)velocity,and the sense of(e)force,(f)muscle tension,(g)weight,and(h)size.They apply various paradigms of psychophysics(i.e.,the method of adjustment,constant stimuli,and limits).Conclusion:As the outcomes of different tasks with respect to various body parts show no associations(i.e.,proprioceptive accuracy is characterized by site-specificity and method-specificity),the appropriate measurement method for the task needs to be chosen based on theoretical considerations and/or ecological validity.

Virtual reality training improves balance function

Virtual reality is a new technology that simulates a three-dimensional virtual world on a com- puter and enables the generation of visual, audio, and haptic feedback for the full immersion of users. Users can interact with and observe objects in three-dimensional visual space without limitation. At present, virtual reality training has been widely used in rehabilitation therapy for balance dysfunction. This paper summarizes related articles and other articles suggesting that virtual reality training can improve balance dysfunction in patients after neurological diseases. When patients perform virtual reality training, the prefrontal, parietal cortical areas and other motor cortical networks are activated. These activations may be involved in the reconstruction of neurons in the cerebral cortex. Growing evidence from clinical studies reveals that virtual reality training improves the neurological function of patients with spinal cord injury, cerebral palsy and other neurological impairments. These findings suggest that virtual reality training can acti- vate the cerebral cortex and improve the spatial orientation capacity of patients, thus facilitating the cortex to control balance and increase motion function.

Prevalence of musculoskeletal injuries and a proposal for neuromuscular training to prevent lower limb injuries in Brazilian Army soldiers:an observational study

Background: The activities carried out by soldiers in the army involve great physical demands and require intense trainings to perform combat-specific tasks. Musculoskeletal injury is a potential threat to the health and physical integrity of the soldier. This study aimed to evaluate the prevalence of lower limb musculoskeletal injuries among soldiers and to propose a training protocol to prevent the most frequent injuries.Methods: This observational(cross-sectional) study recruited a sample of 103 soldiers who required medical attention,from a total 202 new battalion soldiers. The medical records(paper and online) had a form of running text. All data collected were recorded by the registered physicians of the battalion medical post. The records were analyzed by the following variables: medical diagnosis, injury site, mechanism, type of treatment, time loss, existence of previous injury,and recurring injury.Results: A total of 112 musculoskeletal injuries were diagnosed in 71 soldiers, and other types of diseases/injuries were diagnosed in the other soldiers. Joint pain accounted for 55.4% of the diagnoses. The knee was the most affected site, while trauma and overload were the most common mechanisms of injury. Drug treatment was used most frequently, accounting for 58% of the cases. The majority of the sample obtained a temporary leave of absence for1 to 6 days or not at all. Previous injuries and recurrence were not presented as risk factors for injury. With the data received, a protocol for the prevention of injuries to the lower limbs was proposed.Conclusions: This study indicated that the most frequent site of injury is the knee, and joint pain is the most common diagnosis. These results may support the necessity to develop a neuromuscular training protocol to prevent lower limb injuries, which we suggest to be applied in future studies.

Principles of postoperative anterior cruciate ligament rehabilitation

It is known that anterior cruciate ligament(ACL) reconstruction needs to be combined with detailed postoperative rehabilitation in order for patients to return to their pre-injury activity levels, and that the rehabilitation process is as important as the reconstruction surgery. Literature studies focus on how early in the postoperative ACL rehabilitation period rehabilitation modalities can be initiated. Despite the sheer number of studies on this topic, postoperative ACL rehabilitation protocols have not been standardized yet. Could common, "ossified" knowledge or modalities really prove themselves in the literature? Could questions such as "is postoperative brace use really necessary?", "what are the benefits of early restoration of the range of motion(ROM)?", "to what extent is neuromuscular electrical stimulation(NMES) effective in the protection from muscular atrophy?", "how early can proprioception training and open chain exercises begin?", "should strengthening training start in the immediate postoperative period?" be answered for sure? My aim is to review postoperative brace use, early ROM restoration, NMES, proprioception, open/closed chain exercises and early strengthening, which are common modalities in the very comprehensive theme of postoperative ACLrehabilitation, on the basis of several studies(Level of Evidence 1 and 2) and to present the commonly accepted ways they are presently used. Moreover, I have presented the objectives of postoperative ACL rehabilitation in tables and recent miscellaneous studies in the last chapter of the paper.

Patients with type 2 diabetes demonstrate proprioceptive deficit in the knee

AIM To investigate proprioceptive discrepancies in the lower extremity in persons with type 2 diabetes mellitus(T2DM). METHODS In this cross-sectional study, a total of 46 older persons were divided into a T2DM group(n = 23) and a control group who did not have T2 DM(n = 23). Participants were given a brief warm up with stretching exercises. Diabetic neuropathy scores were collected prior to proprioceptive testing. For proprioceptive testing, participants performed leg extensions to randomized target positions of 15°, 30°, 45, 60° degrees of elevation in the sagittal plane, each target was repeated a total of four times. Subjects were guided to target positions in the absence of visual feedback via auditory cues from a custom JPS application. When the participant entered the target position, they memorized the location of their limb in space and subsequently attempted to relocate this position in space. Proprioceptive errors were measured from the target positioned, target remembered, target repositioned protocol. RESULTS Proprioceptive accuracy was lower in the diabetic groupat all levels of target angle than the control group(P < 0.05). The diabetic group had 46% greater inaccuracy than the control group at all levels of target position. Diabetics also reported greater neuropathy scores than controls in the past 12 mo P < 0.01. CONCLUSION Deficits in lower limb localization and greater diabetic neuropathy scores were identified in this study. Our findings may be associated with deafferentation as peripheral neuropathy is a common complication with the disease. These findings may help to explain the declining balance function in the older persons with T2DM which is also commonly reported.

Neuromuscular control and rehabilitation of the unstable ankle

Lateral ankle sprain is a common orthopedic injury with a very high recurrence rate in athletes. After decades of research, it is still unclear what contributes to the high recurrence rate of ankle sprain, and what is the most effective intervention to reduce the incident of initial and recurrent injuries. In addition, clinicians often implement balance training as part of the rehabilitation protocol in hopes of enhancing the neuromuscular control and proprioception of the ankle joint. However, there is no consensus on whether the neuromuscular control and proprioception are compromised in unstableankles. To reduce the prevalence of ankle sprains, the effectiveness of engaging balance training to enhance the neuromuscular control and proprioception of the ankle joint is also questionable.

Passive eye movements induced by electromagnetic force(EMF) in rats

Accurate information on eye position in the orbit is available from visual feedback,efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles (EOM).Whereas visual feedback and oculomotor commands have been extensively studied,central processing of EOM proprioceptive signals remains to be elucidated.A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes.A novel method was developed to generate passive eye movements in rats.A small rare-earth magnet disk (0.7 mm diameter,0.5 mm thickness) was attached to the surface of a rat's eyeball.A metal rod (5 mm diameter) wrapped with an electromagnetic (EM) coil was placed near the magnet (8-15 mm).By passing currents to the EM coil,electromagnetic force (EMF) was generated and acted upon the magnet and induced passive eye movements.The EMF induced well-defined passive eye movements,whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration.Peak velocities of the EMF-induced eye movements were linearly related to amplitudes,exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats.Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers.These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.

Haptic interface using tendon electrical stimulation with consideration of multimodal presentation

Background Our previous studies have shown that electrical stimulation from the skin surface to the tendon region(Tendon Electrical Stimulation:TES)can elicit a force sensation,and adjusting the current parameters can control the amount of the sensation.TES is thought to present a proprioceptive force sensation by stimulating receptors or sensory nerves responsible for recognizing the magnitude of the muscle contraction existing inside the tendon,so it can be a proprioceptive module of a small-size,low-cost force feedback device.But there is also suspect that TES presents only strong,noisy skin sensation.From previous study,it was found that TES has some limitation on varying sensations.Methods In this study,in addition to characterizing the proprioceptive sensation induced by TES,we constructed a multimodal presentation system reproducing a situation in which force is applied to the hand was offered,so as to investigate whether TES contributed to the reproduction of haptics cooperating with other modalities,rather than disturbing them.Specifically,we used vibration to present a cutaneous sensation and a visual head mounted display(HMD)system to present simultaneous images.Using this system,we also evaluated the efficacy of TES itself and that of the multimodal system involving TES.Results We found that TES,along with visual and vibration stimulation,contributed to the perception of a certain force.Conclusions Thus,TES appears to be an effective component of multimodal force sense presentation systems.

Efficacy of Slow Reversal Hold and Isometrics in Improving Muscle Strength, Increasing Range of Motion, and Reducing Pain in Patients with Osteoarthritis of Knee

Osteoarthritis of knee is a common problem in the elderly population worldwide. Physical therapy has been shown to be useful in decreasing pain and increasing mobility in this population. The aim of this study was to study the effectiveness of slow reversal hold and isometric exercise techniques in reducing pain, increasing muscle strength, and increasing range of motion for knee flexion in patients with osteoarthritis of knee. The other aim of this study was to compare the relative effectiveness of these two interventions. 60 subjects participated in this study and were randomly assigned either to the slow reversal hold group (n = 30) or, to the isometrics exercise group (n = 30). All subjects performed their respective exercises for 3 weeks. Pain scores using the visual analog scale, muscle strength using manual muscle testing of quadriceps and hamstrings, and range of motion (ROM) for knee flexion using a goniometer were recorded both pre-treatment and post-treatment for both left and right knees. Both the interventions showed a significant decrease in pain scores, an increase in muscle strength, as well as an increase in the ROM. However, ROM was significantly increased in the slow reversal hold group as compared to the isometrics group in both knees. It was concluded that both exercise techniques could be useful in patients with osteoarthritis of knee for decreasing pain and increasing muscle strength. Slow reversal hold technique might be a better technique than isometrics for increasing ROM for knee flexion.

Hand Cooling Enhances the Proprioceptive Drift during Rubber Hand Illusion

Background: The neural representation of the body is easily altered by integrating multiple sensory signals in the brain. The “Rubber Hand Illusion” (RHI) is one of the most popular experimental paradigms to investigate this phenomenon. During this illusion, ownership of a rubber hand is temporarily induced. It was shown that external and continuous cooling of the palm enhanced the RHI, suggesting an association between altered the autonomic nervous system regulation and altered the sense of ownership of a specific limb. Purpose: To investigate whether artificially cooling the entire hand for a short period affects the magnitude of the illusion. Methods: Participants immersed their entire hand in cool, cold, or warm water for 1 min before the RHI procedure. Results: We found that cooling the entire hand enhanced the proprioceptive drift during the RHI but not the subjective feeling of ownership. In contrast, warming and intense cooling of the entire hand did not affect the RHI strength. Conclusion: Our results suggest that transient and moderate cooling of the entire hand was sufficient in enhancing the illusory disembodiment of one’s own hand.

Effect of anterior cruciate ligament reconstruction on biomechanical features of knee in level walking： a meta-analysis

Background The anterior cruciate ligament （ACL） is one of the most commonly injured knee ligaments. Even following ACL reconstruction, significant articular cartilage degeneration can be observed and most patients suffer from premature osteoarthritis. Articular cartilage degeneration and osteoarthritis development after ACL injury are regarded as progressive process that are affected by cyclic loading during frequently performed low-intensity daily activities. The purpose of this study was to perform a meta analysis on studies assessing the effects of ACL reconstruction on kinematics, kinetics and proprioception of knee during level walking.Methods This meta analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials published between January 1966 and July 2010 comparing gait and proprioception of a reconstructed-ACL group with an intact-ACL group were pooled for this review. Thirteen studies were included in the final meta analysis.Results There was no significant difference in step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion between the reconstructed-ACL group and the intact-ACL group （P 〉0.05）. However, there was a significant difference in peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle between the reconstructed-ACL group and the intact-ACL group （P 〈0.05）.Conclusions Step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion usually observed with ACL deficiency were restored after the ACL reconstruction and rehabilitation, but no significant improvements were observed for peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle.

Underlying Mechanisms of Tai-Chi-Chuan Training for Improving Balance Ability in the Elders

Objective： To compare balance ability between elderly individuals who practiced Tai-Chi-Chuan （TCC） for average 9.64 years and elderly individuals who did not practice TCC and its relationship with lower extremity muscle strength and ankle proprioception. Methods： Twenty-five elderly volunteers were divided into two groups according to their TCC practcing experience. Sixteen were TCC group and the other nine were control population. Subjects completed a static balance test and ankle proprioception test using a custom-designed evaluation system, and concentric and eccentric knee extensor and flexor muscle strength tests. Subjects stood on the plate form to measure the proprioception in functional standing position which was differed from the previous studies. Multiple linear regressions were also used to predict the important factor affecting balance. Results： TCC group performed better than the control group in balance, proprioception, and muscle strength of lower extremity. The proprioception was the most important factor related to balance ability and it can be accounted for explaining 44% of variance in medial-lateral sway direction, and 53% of variance in antero-posterior sway direction. The proprioception may be a more important factor which affecting the balance ability. Conclusion： TCC training is recommended to the elders; as it can improve balance ability through better proprioception.

Effect of Taijiquan practice versus wellness education on knee pro-prioception in patients with knee osteoarthritis:a randomized con-trolled trial

OBJECTIVE: To determine the effects of Taijiquan practice on knee proprioception in patients with knee osteoarthritis(OA).METHODS: We conducted a randomized controlled trial comparing Taijiquan with a control condition(wellness education) in patients with knee OA. The patients participated in either a 60-min Taijiquan session three times weekly or a 60-min weekly educational session, for 24 consecutive weeks. The primary outcomes were changes in knee proprioception. Secondary outcomes were changes in the Western Ontario and Mc Master University Osteoarthritis Index(WOMAC).RESULTS: After 24 weeks, compared with the control group, the Taijiquan group demonstrated better improvements in the joint position sense in knee flexion(left:-2.12°; right:-2.02°), and knee extension(left:-2.22°; right:-1.54°). In addition,the Taijiquan group showed significantly greater improvements in the WOMAC scores(P < 0.05) for knee pain(left:-3.17 points; right:-3.74 points),stiffness(left:-2.43 points; right:-2.13 points),and physical function(left:-10.99 points; right:-8.00 points), compared with the control group.CONCLUSION: A 24-week Taijiquan practice resulted in a significant improvement in knee proprioception in patients with knee OA. The present findings add increasing evidence regarding the clinical benefits of Taijiquan as a therapeutic modality for patients to improve the reflex protection of knee joints against potentially harmful forces.