Proprioceptive Acuity Research Articles

Various methods to assess knee proprioception

Introduction: Proprioception is a vital aspect of motor control and when degraded or lost can have a profound impact on function in diverse clinical populations. This systematic review aimed to identify clinically related tools to measure proprioceptive acuity. The major purpose of this systematic review was to identify and categorise the methods that have been developed and utilised to test proprioceptive accuracy in a comprehensive manner. Methods: The pub med, Scopus, Web of Science and the other search engine/databases used: Cochrane database / SCIRE / PEDro / CINAHL/ EMBASE, ERIC were systematically searched. Conclusions: The TTDPM method has less relative ecological validity, but has high conceptual purity, Although JPR tests may have less relative test validity, but more clinically feasible, The AMEDA method appears to have better ecological validity and relatively better test validity and data validity.

Assessing proprioceptive acuity in people with multiple sclerosis.

BackgroundProprioceptive acuity and impairments in proprioceptively guided reaches have not been comprehensively examined in people with multiple sclerosis (MS).ObjectiveTo examine proprioceptive acuity in people with MS who self-report and who do not self-report upper limb (UL) impairment, and to determine how people with MS reach proprioceptive targets.MethodsTwenty-four participants with MS were recruited into two groups based on self-reported UL impairment: MS-R (i.e. report UL impairment; n = 12) vs. MS-NR (i.e. do not report UL impairment; n = 12). Proprioception was assessed using ipsilateral and contralateral robotic proprioceptive matching tasks.ResultsParticipants in the MS-R group demonstrated worse proprioceptive acuity compared to the MS-NR group on the ipsilateral and contralateral robotic matching tasks. Analyses of reaches to proprioceptive targets further revealed that participants in the MS-R group exhibited deficits in movement planning, as demonstrated by greater errors at peak velocity in the contralateral matching task in comparison to the MS-NR group.ConclusionOur findings suggest that people with MS who self-report UL impairment demonstrate worse proprioceptive acuity, as well as poorer movement planning in comparison to people with MS who do not report UL impairment.

Extracurricular sports activities modify the proprioceptive map in children aged 5–8 years

The Chinese government has recently issued the strictest ever guideline to improve the compulsory education system. The new policy aims at reducing the burden of excessive homework and supplementary tutoring, whilst promoting extracurricular activities, including sports and arts, for primary and junior middle school students. To examine the impact that this reform might have on sensory development—which is critical for higher-order cognitive functions—we assessed proprioceptive abilities in children from 5 to 8 years of age. Proprioception refers to sensations of position and motion of the body in space and is mediated by activity in somatosensory and prefrontal cortical areas. By asking participants to perform position matching tasks in the forward–backward directions, we were able to compare the proprioceptive maps of children with and without regular sports training. We demonstrate that extracurricular sports activities can modify the proprioceptive map and improve proprioceptive acuity and stability in school-aged children.

Proprioceptive manipulations in orthograde posture modulate postural control in low back pain patients: a pilot study

As we stand upright, perceptual afferences are crucial to successfully help generating postural motor commands. Non-Specific Low Back Pain patients frequently demonstrate a lack of proprioceptive acuity, often translating into postural control deficiencies. For the first time, to our knowledge, we studied the postural effects of proprioceptive manipulations in orthograde posture on Non-Specific Low Back Pain patients. Using static posturography recordings, we computed sway speed, speed variance, and the main direction of sway. We also addressed the patient’s subjective feedbacks after being manipulated. Five minutes after the proprioceptive manipulations, our results revealed decreased speed and speed variance outcomes, but the main direction of sway was not modulated. Furthermore, after the proprioceptive manipulations, the patients also self-reported improved clinical outcomes. These findings provide new knowledge opening new fields of research as well as potential treatment strategies in Low Back Pain patients.

The efficacy of exergaming in patients with knee osteoarthritis: A randomized controlled clinical trial.

Exergaming, one of the most recognized virtual rehabilitation tools, has been shown to be useful for promoting physical activity and enhancing postural stability for neurologic conditions. However, studies with exergaming programs for patients with knee osteoarthritis (OA) are limited. We aimed to investigate the effects of exergaming given by visual and auditory stimulated assisted joint training device in addition to the conventional physiotherapy program on pain intensity, range of motion (ROM), functional status, kinesiophobia, proprioceptive acuity, muscle strength, and postural stability in patients with knee OA. Randomized controlled clinical trial. Sixty patients (47 female, 13 male) with knee osteoarhritis aged 40-65years (57.36±7.26) who were at stage of two to three according to the Kellegren Lawrence radiological evaluation were included in the study. The patients were randomly divided into two groups as study group (conventional physiotherapy+exergaming) and control group (conventional physiotherapy). Electrotherapy and exercise program were applied to both of the groups along 5days a week for 6weeks but exergaming only applied to study group. ROM, pain intensity, proprioceptive acuity, kinesiophobia, muscle strength, and postural stability of the patients were evaluated at the beginning and end of the treatment. In the intra-group analyses of all the assessments of the patients, there was a significant difference in the positive direction in both groups, except for the postural stability values. In the intra-group analyses of postural stability, there was a significant increase only in the study group. In comparison between the groups, proprioceptive acuity, ROM, functional status, and postural stability scores were significantly increased in the study group according to the control group; pain and kinesiophobia decreased significantly. In this study, the exergaming accompanied with conventional physiotherapy programs resulted more positive improvements on pain, ROM, postural stability, kinesiophobia, proprioceptive acuity, and functional status in patients with knee OA compared to the conventional physiotherapy program alone.

High proprioceptive acuity in slow and fast hand movements.

We can accurately reach to touch our index fingertip to various points on the body without vision. Awareness of location/motion of the index fingertip and other body parts through proprioception is required for such movements. Proprioception involves processing sensory information, but it is also debated whether internal model estimates of body state from motor commands improve proprioception. We tested the hypothesis that proprioceptive errors increase with increases in speed of hand movement and whether an internal model contributes to more accurate proprioception, especially in higher speed movements. Ten subjects made voluntary reaching movements with their dominant arm to touch its index-tip to the index-tip of the non-dominant arm that was moved passively or actively at three speeds (slow, comfortable, fast) in various directions. Four conditions required the experimenter to passively move the subject's target arm at slow, comfortable and fast speeds and in different directions. A fifth condition required the subject to actively move both arms to perform the task. Subjects performed these tasks with high accuracy during slow and comfortable speed movements of the target arm. Errors averaged 3.7mm larger when the target was moved faster and were equivalent to errors for slower movements (p < 0.014). Errors in the active and passive target movement conditions were also equivalent (p < 0.001). These findings show that proprioception is accurate across many different speeds of passive and active target motion and that there was no evidence than an internal model contributes to improved accuracy of proprioception during active movements.

Improved proprioception does not benefit visuomotor adaptation.

Visuomotor adaptation arises when reaching in an altered visual environment, where one’s seen hand position does not match their felt (i.e., proprioceptive) hand position in space. Here, we asked if proprioceptive training benefits visuomotor adaptation, and if these benefits arise due to implicit (unconscious) or explicit (conscious strategy) processes. Seventy-two participants were divided equally into 3 groups: proprioceptive training with feedback (PTWF), proprioceptive training no feedback (PTNF), and Control (CTRL). The PTWF and PTNF groups completed passive proprioceptive training, where a participant’s hand was moved to an unknown reference location and they judged the felt position of their unseen hand relative to their body midline on every trial. The PTWF group received verbal feedback with respect to their response accuracy on the middle 60% of trials, whereas the PTNF did not receive any feedback during training. The CTRL group did not complete proprioceptive training and instead sat quietly during this time. Following proprioceptive training or time delay, all three groups reached when seeing a cursor that was rotated 30° clockwise relative to their hand motion. The experiment ended with participants completing a series of no-cursor reaches to assess implicit and explicit adaptation. Results indicated that the PTWF group improved the accuracy of their sense of felt hand position following proprioceptive training. However, this improved proprioceptive acuity (i.e., the accuracy of their sense of felt hand) did not benefit visuomotor adaptation, as all three groups showed similar visuomotor adaptation across rotated reach training trials. Visuomotor adaptation arose implicitly, with minimal explicit contribution for all three groups. Together, these results suggest that passive proprioceptive training does not benefit, nor hinder, the extent of implicit visuomotor adaptation established immediately following reach training with a 30° cursor rotation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00221-022-06352-4.

Association Between Neck Pain, Range of Motion, and Proprioception in Elite Female International Standard Dancers: A Case-Control Study

Neck pain is common in dancers, especially female dancers, and the injury pattern varies in different genres of dance. Among dancesport performers, intensive neck left rotation is required in female International Standard dancers, but it is unknown whether neck pain is associated with neck rotation range of motion and proprioception. To explore the associations between neck pain, cervical rotation range of motion, and proprioception in female International Standard dancers. Twelve dancers with dance-related neck pain (age 19.9±1.9 yrs) volunteered, matched with 12 not reporting neck pain (age 22.2±2.4 yrs). A 100-mm visual analog scale (VAS) was used to record neck pain. Active rotation range of motion (AROM) of the cervical spine was measured using a tape measure. A cervical rotation reposition test that used a head-mounted laser projector on a linear scale was employed to measure the cervical spine proprioception, and the absolute error (AE) and variable error (VE) were calculated as proprioceptive acuity scores. Nine of 12 participants in the group with neck pain declared left side pain, with 2 reporting pain on both sides. The group with neck pain had significantly lower left rotation AROM (p<0.05). For proprioceptive acuity, mixed model ANOVA only showed that repositioning of the right side of the neck is more accurate and consistent than that of the left (both AE and VE p<0.05). Linear regression analysis indicated that left rotation AROM was significantly influenced by left neck pain (t=3.061, p=0.006, adjusted R2 = 0.267, and Durbin-Watson value = 1.776). Most participants in the group with neck pain showed left side pain, associated with decreased left rotation AROM. Early screening on cervical rotation mobility may be necessary to reduce future dance-related injury after the onset of neck pain. Proprioceptive acuity of the left side neck was significantly impaired compared with that of the right, indicating future proprioceptive intervention on the left side neck.

Identifying Pain Modulating Brain Mechanisms After Qigong Practice For Pain Reduction In Adults With Chronic Low Back Pain: A Proof Of Concept Study

Research Objectives Twenty million Americans suffer from chronic low back pain (cLBP). Due to the limited success of medications, mind and body approaches that incorporate mindful movement have potential for cLBP because movement is often impaired. Qigong is accessible due to its gentle movements and dual focus on breathing and body awareness. Our previous research and others found that two brain areas (parietal operculum, insula) are important brain areas for body awareness and pain perception. We determined the proof of concept in demonstrating pain-related brain function changes after Qigong or exercises concurrent with changes in pain and associated outcomes. Design Randomized pilot clinical trial. Setting University of Minnesota with remote intervention. Participants Our goal is to enroll 32 participants. To date 12 participants (2 men, 10 women, average age 45.5 years) were randomized into the Qigong practice (n=6) or P.Volve (n=6) group and completed the study. Interventions The Qigong group practiced the “5 Elements Qigong Healing”. The active comparison group received low-impact exercises designed by P.Volve, which focuses on core strengthening and stabilization. Both groups received a video link to practice at home with 40min/session videos, 3x/week for 12 weeks. Main Outcome Measures We performed 3 fMRI tasks: mental focus on low back pain; an imagined Qigong movement; shape discrimination (MRI-compatible robot). Our patient self-reported measures were pain intensity levels/week; functional tasks, Modified Roland-Morris disability questionnaire, 4 body awareness scales, proprioceptive acuity, core strength, and balance. All assessments were performed before and after the 12-week interventions. Results In the MRI, parietal operculum activation reduced during the Qigong task (Qigong group) and during the mental focus on low back pain task (P.Volve group). These brain function changes were seen alongside within-group improvement in our self-reported measures (effect-sizes d=1.1-2.0), and in strength and balance (d=0.76-1.68). Conclusions Our observations so far support our proof of concept and presents the first step to understanding the brain mechanisms of alternative treatments that improve dysfunctional pain processing in the brain to reduce LBP. Author(s) Disclosures No conflict of interest. Twenty million Americans suffer from chronic low back pain (cLBP). Due to the limited success of medications, mind and body approaches that incorporate mindful movement have potential for cLBP because movement is often impaired. Qigong is accessible due to its gentle movements and dual focus on breathing and body awareness. Our previous research and others found that two brain areas (parietal operculum, insula) are important brain areas for body awareness and pain perception. We determined the proof of concept in demonstrating pain-related brain function changes after Qigong or exercises concurrent with changes in pain and associated outcomes. Randomized pilot clinical trial. University of Minnesota with remote intervention. Our goal is to enroll 32 participants. To date 12 participants (2 men, 10 women, average age 45.5 years) were randomized into the Qigong practice (n=6) or P.Volve (n=6) group and completed the study. The Qigong group practiced the “5 Elements Qigong Healing”. The active comparison group received low-impact exercises designed by P.Volve, which focuses on core strengthening and stabilization. Both groups received a video link to practice at home with 40min/session videos, 3x/week for 12 weeks. We performed 3 fMRI tasks: mental focus on low back pain; an imagined Qigong movement; shape discrimination (MRI-compatible robot). Our patient self-reported measures were pain intensity levels/week; functional tasks, Modified Roland-Morris disability questionnaire, 4 body awareness scales, proprioceptive acuity, core strength, and balance. All assessments were performed before and after the 12-week interventions. In the MRI, parietal operculum activation reduced during the Qigong task (Qigong group) and during the mental focus on low back pain task (P.Volve group). These brain function changes were seen alongside within-group improvement in our self-reported measures (effect-sizes d=1.1-2.0), and in strength and balance (d=0.76-1.68). Our observations so far support our proof of concept and presents the first step to understanding the brain mechanisms of alternative treatments that improve dysfunctional pain processing in the brain to reduce LBP.

GENDER DIFFERENCE IN KNEE JOINT PROPRIOCEPTION IN HEALTHY ASYMPTOMATIC INDIVIDUALS - AN OBSERVATIONAL STUDY.

Introduction: Proprioception is a sense of movement which is ability to perceive direction and velocity and sense of force,which is ability to estimate amount of muscular force generated. It may vary due to may factors like degenerative changes, activity level,injury,age, gender and dominence, so this study is to evaluate the difference of knee joint proprioception in both males and females. Purpose:The purpose of this study is to evaluate the gender difference in knee joint proprioception in healthy asymptomatic individuals. Methodology: 60 participants of both genders were included in this study, joint position error was assessed using goniometer in high sitting position, with eyes blindfolded. Joint position senses of both knees were assessed at 15, 30 and 45 degrees, and the mean of 3 readings at each angle was considered for analysis. Result: Joint position sense shows: In Females at 15º:- Right (2.618±1.471) , Left (3.274±1.55) , 30º Right (5.362± 1.021) Left(5.797 ±1.074) , 45º Right (6.585 ±1.883) Left (5.997 ±1.253) respectively. In Males at 15º Right (1.151 ±0.87) left (1.286 ±0.791); 30º Right (3.53± 0.855) Left (3.641± 1.012);45ºRight (3.875± 0.894) left (3.985 ±1.018) respectively. Conclusion: Gender difference found in knee joint proprioception in healthy asymptomatic individuals, females have less proprioception acuity than males.

Ankle complex proprioception and plantar cutaneous sensation in older women with different physical activity levels

Ankle complex proprioception and plantar sole sensitivity have been separately reported to be essential sensory components in balance control among the elderly. However, their inter-relationship is still unknown. Further, although optimal proprioceptive ability has been related to regular physical exercise, the association between physical activity (PA) levels, ankle proprioceptive acuity and plantar cutaneous sensation is unclear. Therefore, this study aims to compare ankle proprioceptive acuity and plantar cutaneous sensitivity scores between groups of older women with different PA levels, and to determine any relationships between plantar sole cutaneous sensitivity, ankle proprioceptive performance and PA levels. 68 older female participants were recruited who were distributed over three PA levels: highly active, moderately active, and inactive. PA level was assessed by the International Physical Activity Questionnaire. Ankle proprioceptive acuity was tested in full weight-bearing stance using the ankle Active Movement Extent Discrimination Apparatus (AMEDA) and plantar cutaneous sensitivity was assessed with the Nylon Semmes-Weinstein monofilaments test. Results showed that ankle proprioceptive acuity scores were strongly positively related to plantar sole sensitivity scores (r = 0.80, p < 0.001; effect size: η2 = 0.715), and both scores correlated with PA level. In conclusion, plantar cutaneous sensitivity and ankle complex proprioception were strongly correlated in older females with different levels of physical activity, suggesting that the former may be an integral part of the latter. Given the previously reported contribution of AMEDA ankle proprioceptive acuity to sport performance level, the health of the plantar sole of the foot may be important as a performance determinant.

Proprioceptive sensitivity to imposed finger deflections.

Hand proprioception, the sense of the posture and movements of the wrist and digits, is critical to dexterous manual behavior and to stereognosis, the ability to sense the three-dimensional structure of objects held in the hand. To better understand this sensory modality and its role in hand function, we sought to characterize the acuity with which the postures and movements of finger joints are sensed. To this end, we measured the ability of human subjects to discriminate changes in posture and speed around the three joints of the index finger. In these experiments, we isolated the sensory component by imposing the postures on an otherwise still hand, to complement other studies in which subjects made judgments on actively achieved postures. We found that subjects could reliably sense 12-16% changes in joint angle and 18-32% changes in joint speed. Furthermore, the acuity for posture and speed was comparable across the three joints of the finger. Finally, task performance was unaffected by the presence of a vibratory stimulus, calling into question the role of cutaneous cues in hand proprioception.NEW & NOTEWORTHY Manual dexterity and stereognosis are supported by two exquisite sensory systems, namely touch and proprioception. Here, we measure the sensitivity of hand proprioception and show that humans can sense the posture and movements of the fingers with great accuracy. We also show that application of a skin vibration does not impair sensitivity, suggesting that proprioceptive acuity relies primarily on receptors in the muscles (and possibly tendons) rather than the skin.

Impaired wrist position sense is linked to motor abnormalities in young adults with a probable developmental coordination disorder

Proprioceptive deficits have been found to underlie motor abnormalities in individuals with movement disorders. This study investigated wrist proprioceptive acuity in young adults with and without probable developmental coordination disorder (DCD) and examined how proprioceptive acuity is linked to different domains of motor function. Thirty participants were included in this study (age, 19–22 years), ten with probable DCD and 20 controls. Wrist proprioceptive acuity was assessed using a joint position sense paradigm under contralateral and ipsilateral conditions. The Bruininks − Oseretsky Test of Motor Proficiency 2nd Edition (BOT-2) was used to measure different domains of motor ability. Compared to the control group, young adults with probable DCD exhibited significantly increased proprioceptive error variability in contralateral (p < 0.0001) and ipsilateral conditions (p < 0.05). Furthermore, wrist proprioceptive error variability was significantly associated with the levels of body coordination measured by BOT-2 (r = − 0.55). This study verified impaired wrist proprioceptive function in young adults with probable DCD, which is likely to contribute to motor impairment in adults with DCD.

The Effect of Eight Weeks of Water Training on Postural Control and Balance Recovery Strategies in 60-70 Years Old Elderly Men

Background and Aims The risk of falling in people increases with aging. Aquatic exercises create a secure environment for people, and they can reduce the risk of falling among elderly people. This study aimed to investigate the effect of 8 weeks of aquatic exercises on postural control and balance recovery strategies. Methods Thirty elderly people from Kerman province were selected to participate in the research, and they were randomly divided into control (Mean±SD age 63.67±2.58 years, height 169.27±4.74 cm, and weight 71.00±6.95 kg) and intervention groups (Mean±SD age 65.00±3.07 years, height 169.50±27.34 cm, and weight 71.200±4.31 kg). The postural control and balance recovery strategies during sudden movement by treadmill were evaluated using the Biodex and motion analysis system. The intervention group participated in aquatic exercises for 8 weeks (3 times with 45 minutes per week) to challenge the physical and proprioceptive acuity, while the control group lived without any interventions. Data were analyzed using the ANCOVA and Pearson correlation tests (P&lt;0.05). Results The results showed a significant improvement in the scores of postural control and balance recovery strategies (P&lt;0.05). Balance strategies in elderly people moved from the hip toward the ankle (P&lt;0.05). The onset time of muscle activity and the electrical activation of muscles in elders showed significant improvement after participating in this study (P&lt;0.05). Conclusion The results approved that water training has significantly affected the ability to control posture and balance recovery strategies in the elderly and that changing the pattern of muscle activation has increased postural stability and improved balance. It recommends using these exercises in training programs for the elderly to decrease the risk of falls and improve balance.

Passive Proprioceptive Training Alters the Sensitivity of Muscle Spindles to Imposed Movements.

Humans rely on precise proprioceptive feedback from our muscles, which is important in both the acquisition and execution of movements, to perform daily activities. Somatosensory input from the body shapes motor learning through central processes, as demonstrated for tasks using the arm, under active (self-generated) and passive conditions. Presently, we investigated whether passive movement training of the ankle increased proprioceptive acuity (psychophysical experiment) and whether it changed the peripheral proprioceptive afferent signal (microneurography experiment). In the psychophysical experiment, the ankle of 32 healthy human participants was moved passively using pairs of ramp-and-hold movements in different directions. In a pretraining test, participants made judgements about the movement direction in a two-alternative forced choice paradigm. Participants then underwent passive movement training, but only half were cued for learning, where a reference position was signaled by a sound and the participant had to learn to recognize this position; they then completed a post-training test. In a paradigm using the same setup, nine healthy participants underwent microneurography recordings of Ia muscle afferents from the peroneal nerve, where all were cued during training. In the psychophysical experiment, proprioceptive acuity improved with training only in the cued group. In the microneurography experiment, we found that muscle afferent firing was modulated, via an increase in the dynamic index, after training. We suggest that changes in muscle afferent input from the periphery can contribute to and support central perceptual and motor learning, as shown under passive conditions using ankle movements, which may be exploited for movement rehabilitation.

Proprioceptive Gaming: Making Finger Sensation Training Intense and Engaging with the P-Pong Game and PINKIE Robot.

Proprioceptive deficits are common after a stroke and are thought to negatively impact motor learning. Despite this, there is a lack of practical robotic devices for assessing proprioception, as well as few robotic rehabilitation techniques that intensely and engagingly target proprioception. This work first presents the design of a simple robotic device, PINKIE, developed to assess and train finger proprioception. PINKIE uses low-cost actuators and sensors and is fabricated completely from 3D printed, laser cut, and off-the-shelf components. We then describe the design and testing of a gamified proprioceptive training technique, Proprioceptive-Pong (P-Pong), implemented with PINKIE. In P-Pong, players must continuously make game decisions based on sensed index and middle finger positions, as the game robotically moves their fingers instead of screen pixels to express the motion of the ball and paddle. We also report the results of a pilot study in which we investigated the effect of a short bout of P-Pong play on proprioceptive acuity, and quantified user engagement and intrinsic motivation of game play. We randomly assigned 15 unimpaired human participants to play 15 minutes of P-Pong (proprioceptive training group) or a similar but video-only version of Pong (control group). We assessed finger proprioception acuity before and after game play using the Crisscross assessment previously developed by our laboratory, engagement using the User Engagement Scale, and motivation using the Intrinsic Motivation Inventory survey. Following game play, there was a significant improvement in proprioceptive acuity (2.2 ± 2.6 SD mm, p = 0.023) in the proprioceptive training group but not the control group (0.5 ± 0.9 SD mm, p = 0.101). Participants rated P-Pong highly on all survey subscales, and as highly as visual Pong, except in the Perceived Usability and Competence subscales, a finding we discuss. To our knowledge, this work presents the first computer gaming approach for providing intense and engaging finger proprioception training, by splitting the feedback of game elements between the visual and proprioceptive senses. The pilot experiment indicates that the human sensory motor system has the ability to at least temporarily improve proprioception acuity with such game-based training.

Effect of Load, Angle, and Contraction Type on Clinically Assessed Knee Joint Position Sense.

Proprioception is an individual's awareness of body position in 3-dimensional space. How proprioceptive acuity changes under varying conditions such as joint position, load, and concentric or eccentric contraction type is not well understood. In addition, a limitation of the variety of techniques to assess proprioception is the lack of clinically feasible methods to capture proprioceptive acuity. The purpose of this study was to implement a readily available instrument, a smartphone, in the clinical evaluation of knee active joint position sense and to determine how joint angle, joint loading, and quadriceps contraction type affect an individual's active joint position sense. Cross-over study. Twenty healthy, physically active university participants (10 women and 10 men: 21.4 [2.0]y; 1.73 [0.1]m; 70.9 [14.3]kg) were recruited. Individuals were included if they had no neurological disorder, no prior knee surgery, and no recent knee injury. The participants were given a verbal instruction to locate a target angle and then were tasked with reproducing the target angle without visual or verbal cues. An accelerometer application on a smartphone was used to assess the angle to the nearest tenth of a degree. Three variables, each with 2 levels, were analyzed in this study: load (weighted and unweighted), contraction type (eccentric and concentric), and joint position (20° and 70°). A repeated-measures analysis of variance was conducted to assess the within-subjects factors of load, contraction, and position. A significant difference of 0.50° (0.19°) of greater error with eccentric versus concentric contraction (P = .02) type was identified. In addition, a significant interaction was found for contraction × position, with a mean increase in error of 0.98° (0.33°) at the 20° position when contracting eccentrically (P = .03). Contraction type, specifically eccentric contraction at 20°, showed significantly greater error than concentric contraction. This suggests that, during eccentric contractions of the quadriceps, there may be decreased proprioceptive sensitivity compared with concentric contractions.

The effect of static stretching of agonist and antagonist muscles on knee joint position sense

Background/Aims Proprioception acuity is important in sports activities and stretching is widely used in warm-up programmes. The main objective of this study was to evaluate if a warm-up programme with and without stretching flexors and extensors muscles could affect knee joint position sense. Methods The effects of different stretching regimens on joint position sense were examined. A total of 12 semi-professional football players completed four warm-up sessions over 4 weeks: standard warm-up programme; standard warm-up programme with quadriceps stretching; standard warm-up programme with hamstring stretching; and standard warm-up programme with stretching of both quadriceps and hamstrings. Open kinetic chain knee joint position sense was estimated from the ability to reproduce the three target angles (20°, 45° and 60° knee flexion) in the dominant limb before and after the intervention. Results In the absolute angular error, there was a statistically significant three-way interaction between the warm-up programme, target angle and time (F (6, 54)=6.88, P=0.001). Findings of post-hoc analysis demonstrated that there was a statistically significant difference between the pre- and post-stretching of hamstrings for the target angles of 20° (4.70 vs 1.57, P=0.01), 45° (1.70 vs 4.50, P=0.02), and 60° (1.93 vs 4.20, P=0.02). In the relative angular error, interaction of time by the warm-up programme was significant (F (3, 27)=3.41, P=0.03). Conclusions The warm-up programme with static stretching of hamstrings had a negative effect on open kinetic chain knee joint position sense during the flexion to extension repositioning task, which may not only have a negative effect on performance of athletes as a part of warm-up exercises, but may also lead to further injuries.

Direction-Specific Signatures of Sport Participation in Center of Pressure Profiles of Division I Athletes.

BackgroundDescriptive and comparative studies of human postural control generally report effects for component or resultant dimensions of a measured signal, which may obscure potentially important information related to off-cardinal directionality. Recent work has demonstrated highly specific balance behavior that is often not easily reconciled with conventional theories of postural control.PurposeThe purpose of this study was to quantify the effects of sport-specific training history on directional profiles of center of pressure (COP) displacement and velocity among collegiate athletes.Study DesignCross-Sectional Study.MethodsOne-hundred sixty-seven NCAA Division-I varsity athletes (80 female: 19.12±1.08 years, 169.79±7.03 cm, 65.69±10.43 kg; 87 male: 19.59±1.33 years, 181.25±9.06 cm, 76.40±12.73 kg) representing four sports (basketball, soccer, tennis, and cross county) participated in this study. Participants balanced barefoot with eyes closed on a force plate for 10-s. in double leg and single leg stance. Effects of sport on mean COP velocity and total displacement were assessed within eight non-overlapping directions (i.e. heading bins).ResultsGreater double leg COP displacement and velocity were observed within specific heading bins in cross country athletes when compared to soccer athletes. Greater double leg COP velocity was also observed in multiple heading bins in basketball athletes when compared to soccer athletes. Greater single leg (non-dominant limb) COP displacement was observed in the 135° heading bin in basketball athletes when compared to soccer athletes.ConclusionsThe observed effects are likely attributable to sport-specific sensorimotor adaptations, including lower extremity strength/power, proprioceptive acuity, and efficiency of integrating vestibular information. Other potential mechanism—namely the involvement of cutaneous feedback and/or muscle synergies—deserve consideration. Directional profiling of spontaneous COP motion may improve understanding of sport-related balance behavior, enhancing its application in therapeutic and performance monitoring contexts.Level of evidence3b

Knee proprioceptive function and physical performance of patients with patellofemoral pain: A matched case-control study

BackgroundPatients with patellofemoral pain (PFP) present pain, functional limitation, and alteration in knee proprioception. PurposeTo compare the knee joint position sense and lower extremity functionality between patients with PFP and controls. Secondarily, investigate the relationship between proprioceptive acuity and physical performance. MethodsThis is a matched case-control study including 48 patients with PFP and 48 healthy individuals matched by age, sex, weight, height, and limb dominance. The proprioceptive evaluation was performed using the joint position sense test (absolute error and relative error) and functionality was assessed using the Single-Leg Triple-Hop test and the Y-Balance Test. The groups were compared using the independent student’s T-test. Proprioceptive acuity and physical performance correlations were determined by Pearson correlation coefficient. ResultsParticipants were on average 31 years old and 62.5% were men. There was no statistically difference for absolute and relative angular error between groups. Patients presented lower relative reached distance on the anterior direction of the Y-Balance Test than controls [patients=58.6 (6.6) % versus controls=61.7 (5.9) %, p=.020]. No differences between groups were found for other functional measures. Significant correlation was found between absolute angular error and anterior component at 60° (r=0.225, p=.028) and relative angular error at 60° with the posterolateral component of the Y- Balance Test (r=0.231, p=.024). ConclusionProprioceptive acuity of patients with PFP was not reduced. The anterior direction of the Y-Balance Test was impaired compared to matched controls. Proprioceptive sense is related to dynamic balance but not to jump ability.