Proprioceptive acuity in the frontal and sagittal planes of the knee: a preliminary study

Six weeks of multistation program on the knee proprioception and performance of futsal players

BACKGROUND

Proprioception and vertical jump are important parameters in the performance and prevention of injuries in futsal. However, very few studies have analyzed the role of multistation exercises to improve these variables. The purpose of this study was to assess the effects of a six-week multistation exercise program on knee joint position sense (JPS) and countermovement jump (CMJ) of futsal players.

METHODS

Thirty-four male futsal players randomly classified into experimental (N.=17) or control group (N.=17). The experimental group included a multistation exercise protocol to their training routines (2 times/week - 6 weeks); the control group continued their training routines. All the players completed similar training routines outside of the multistation exercises. Before (baseline), just after the intervention (Post6Wk) and four weeks later (Post10Wk), CMJ and knee JPS (absolute, relative and variable angular error: AAE, RAE and VAE, respectively) were evaluated.

RESULTS

ANOVA showed that the experimental group significantly decreased VAE at Post10Wk compared to baseline, suggestive of greater proprioceptive precision, while the control group significantly increased AAE, RAE and VAE at Post10Wk compared to baseline. The experimental group exhibited lower and thus, better AAE and VAE than the control group at Post10Wk, although no significant differences were found at Post6Wk. No significant differences was found in the CMJ.

CONCLUSIONS

A six weeks of multistation program may help improve proprioceptive precision of futsal players, even one month after finishing the 6-wk multistation training program. However, this is not long enough to improve proprioceptive acuity and maximum vertical jump. Therefore, the meaningful of these results in term of performance are unclear.

Does gender make a difference in knee rotation proprioception and range of motion in healthy subjects?

BACKGROUND

Knee proprioception is an integral component of neuromuscular control system that stabilizes the joints, reducing incidence of injury. Knee injuries' incidences differ between genders. Knee rotation is a component of different knee injury mechanisms. Gender differences in knee proprioception in internal (IR) and external (ER) rotations are not sufficiently studied.

OBJECTIVE

To check whether proprioceptive acuity in IR and ER directions of knee rotation is inherently lower in women compared to men. Moreover, to assess gender difference in ranges of knee rotation.

METHODS

Thirty volunteers (15 women and 15 men) participated. Knee proprioception acuity and ranges of knee rotation were assessed using the knee rotatory kinesthetic device (KRKD). Proprioception was tested using absolute judgment task, subject's ability to discriminate different rotation movements (stimuli) randomly presented, then just notable difference (JND) was calculated; least difference accurately discriminated in 75% of trials.

RESULTS

Women had lower proprioception acuity in IR than men (1.70∘± 0.79∘ and 1.12∘± 0.32∘, p= 0.011) respectively. Active IR (women: 41.29∘± 7.46∘, men 32.80∘± 3.64∘, p= 0.000), and passive IR (women: 53.43∘±11.67∘, men: 37.94∘± 5.22∘, p= 0.000) were higher in women compared to men. Active ER (women: 49.71∘± 11.37∘, men: 39.16∘± 5.46∘, p= 0.003), and passive ER (women: 62.29∘± 13.74∘, men: 48.89∘± 7.09∘, p= 0.002) were, also, higher in women.

CONCLUSION

Gender difference in knee proprioception acuity was found in IR, which is the direction of rotation that anterior cruciate ligament (ACL) stabilize. Women's ranges of knee rotation are greater than men in both IR and ER.

Foot placement control and gait instability among people with stroke

Gait instability is a common problem following stroke, as evidenced by increases in fall risk and fear of falling. However, the mechanism underlying gait instability is currently unclear. We recently found that young, healthy humans use a consistent gait stabilization strategy of actively controlling their mediolateral foot placement based on the concurrent mechanical state of the stance limb. In the present work, we tested whether people with stroke (n = 16) and age-matched controls (n = 19) used this neuromechanical strategy. Specifically, we used multiple linear regressions to test whether (1) swing phase gluteus medius (GM) activity was influenced by the simultaneous state of the stance limb and (2) mediolateral foot placement location was influenced by swing phase GM activity and the mechanical state of the swing limb at the start of the step. We found that both age-matched controls and people with stroke classified as having a low fall risk (Dynamic Gait Index [DGI] score >19) essentially used the stabilization strategy previously described in young controls. In contrast, this strategy was disrupted for people with stroke classified as higher fall risk (DGI </=19), particularly for steps taken with the paretic limb. These results suggest that a reduced ability to appropriately control foot placement may contribute to poststroke instability.

Robot-aided assessment of lower extremity functions: a review

The assessment of sensorimotor functions is extremely important to understand the health status of a patient and its change over time. Assessments are necessary to plan and adjust the therapy in order to maximize the chances of individual recovery. Nowadays, however, assessments are seldom used in clinical practice due to administrative constraints or to inadequate validity, reliability and responsiveness. In clinical trials, more sensitive and reliable measurement scales could unmask changes in physiological variables that would not be visible with existing clinical scores.In the last decades robotic devices have become available for neurorehabilitation training in clinical centers. Besides training, robotic devices can overcome some of the limitations in traditional clinical assessments by providing more objective, sensitive, reliable and time-efficient measurements. However, it is necessary to understand the clinical needs to be able to develop novel robot-aided assessment methods that can be integrated in clinical practice.This paper aims at providing researchers and developers in the field of robotic neurorehabilitation with a comprehensive review of assessment methods for the lower extremities. Among the ICF domains, we included those related to lower extremities sensorimotor functions and walking; for each chapter we present and discuss existing assessments used in routine clinical practice and contrast those to state-of-the-art instrumented and robot-aided technologies. Based on the shortcomings of current assessments, on the identified clinical needs and on the opportunities offered by robotic devices, we propose future directions for research in rehabilitation robotics. The review and recommendations provided in this paper aim to guide the design of the next generation of robot-aided functional assessments, their validation and their translation to clinical practice.

Hip proprioceptive feedback influences the control of mediolateral stability during human walking

Active control of the mediolateral location of the feet is an important component of a stable bipedal walking pattern, although the roles of sensory feedback in this process are unclear. In the present experiments, we tested whether hip abductor proprioception influenced the control of mediolateral gait motion. Participants performed a series of quiet standing and treadmill walking trials. In some trials, 80-Hz vibration was applied intermittently over the right gluteus medius (GM) to evoke artificial proprioceptive feedback. During walking, the GM was vibrated during either right leg stance (to elicit a perception that the pelvis was closer mediolaterally to the stance foot) or swing (to elicit a perception that the swing leg was more adducted). Vibration during quiet standing evoked leftward sway in most participants (13 of 16), as expected from its predicted perceptual effects. Across the 13 participants sensitive to vibration, stance phase vibration caused the contralateral leg to be placed significantly closer to the midline (by ∼2 mm) at the end of the ongoing step. In contrast, swing phase vibration caused the vibrated leg to be placed significantly farther mediolaterally from the midline (by ∼2 mm), whereas the pelvis was held closer to the stance foot (by ∼1 mm). The estimated mediolateral margin of stability was thus decreased by stance phase vibration but increased by swing phase vibration. Although the observed effects of vibration were small, they were consistent with humans monitoring hip proprioceptive feedback while walking to maintain stable mediolateral gait motion.

Reliability and validity of using the Lokomat to assess lower limb joint position sense in people with incomplete spinal cord injury

Background

Proprioceptive sense (knowing where the limbs are in space) is critical for motor control during posture and walking, and is often compromised after spinal cord injury (SCI). The purpose of this study was to assess the reliability and validity of using the Lokomat, a robotic exoskeleton used for gait rehabilitation, to quantitatively measure static position sense of the legs in persons with incomplete SCI.

Methods

We used the Lokomat and custom software to assess static position sense in 23 able-bodied (AB) subjects and 23 persons with incomplete SCI (American Spinal Injury Association Impairment Scale level B, C or D). The subject’s leg was placed into a target position (joint angle) at either the hip or knee and asked to memorize that position. The Lokomat then moved the test joint to a “distractor” position. The subject then used a joystick controller to bring the joint back into the memorized target position. The final joint angle was compared to the target angle and the absolute difference was recorded as an error. All movements were passive. Known-groups validity was determined by the ability of the measure to discriminate between able-bodied and SCI subjects. To evaluate test-retest reliability, subjects were tested twice and intra-class correlation coefficients comparing errors from the two sessions were calculated. We also performed a traditional clinical test of proprioception in subjects with SCI and compared these scores to the robotic assessment.

Results

The robot-based assessment test was reliable at the hip and knee in persons with SCI (P ≤ 0.001). Hip and knee angle errors in subjects with SCI were significantly greater (P ≤ 0.001) and more variable (P < 0.0001) than in AB subjects. Error scores were significantly correlated to clinical measure of joint position sense (r ≥ 0.507, P ≤ 0.013).

Conclusions

This study shows that the Lokomat may be used as a reliable and valid clinical measurement tool for assessing joint position sense in persons with incomplete SCI. Quantitative assessments of proprioceptive deficits after neurological injury will help in understanding its role in the recovery of skilled walking and in the development of interventions to aid in the return to safe community ambulation.

Electronic supplementary material

The online version of this article (doi:10.1186/1743-0003-11-167) contains supplementary material, which is available to authorized users.

Assessment of Knee Proprioception in the Anterior Cruciate Ligament Injury Risk Position in Healthy Subjects: A Cross-sectional Study

[Purpose] Knee joint proprioception combines sensory input from a variety of afferent receptors that encompasses the sensations of joint position and motion. Poor proprioception is one of the risk factors of anterior cruciate ligament injury. Most studies have favored testing knee joint position sense in the sagittal plane and non-weight-bearing position. One of the most common mechanisms of noncontact anterior cruciate ligament injury is dynamic knee valgus. No study has measured joint position sense in a manner relevant to the mechanism of injury. Therefore, the aim of this study was to measure knee joint position sense in the noncontact anterior cruciate ligament injury risk position and normal condition. [Subjects and Methods] Thirty healthy male athletes participated in the study. Joint position sense was evaluated by active reproduction of the anterior cruciate ligament injury risk position and normal condition. The dominant knees of subjects were tested. [Results] The results showed less accurate knee joint position sense in the noncontact anterior cruciate ligament injury risk position rather than the normal condition. [Conclusion] The poorer joint position sense in non-contact anterior cruciate ligament injury risk position compared with the normal condition may contribute to the increased incidence of anterior cruciate ligament injury.

A neuromechanical strategy for mediolateral foot placement in walking humans

Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50-100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state.

A neuromechanical strategy for mediolateral foot placement in walking humans

Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50-100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state.

Associations between frontal plane joint stiffness and proprioceptive acuity in knee osteoarthritis

OBJECTIVE

It has been proposed that proprioceptive impairments observed in knee osteoarthritis (OA) may be associated with disease-related changes in joint mechanics. The aim of this study was to quantify joint proprioception and stiffness in the frontal plane of the knee in persons with and without knee OA and to report the associations between these 2 metrics.

METHODS

Participants were 13 patients with knee OA and 14 healthy age-matched subjects. Proprioceptive acuity was assessed in varus and valgus using the threshold to detection of passive movement (TDPM) test. Passive joint stiffness was estimated as the slope of the normalized torque-angle relationship at 0° joint rotation (neutral) and several rotations in varus and valgus. Analyses of variance were performed to determine the effect of OA and sex on each metric. Linear regression was used to assess the correlation between the TDPM and joint stiffness.

RESULTS

The TDPM was significantly higher (P < 0.05) in the OA group compared to the control group for both varus and valgus, but significant sex differences were observed. Passive joint stiffness was significantly reduced (P < 0.05) in OA participants compared to the control group in neutral and valgus, but not varus, and significantly reduced in women compared to men. A weak negative correlation was observed between the TDPM and stiffness estimates, suggesting that poorer proprioception was associated with less joint stiffness.

CONCLUSION

While both joint stiffness and proprioception were reduced in the OA population, they were only weakly correlated. This suggests that other neurophysiologic factors play a larger role in the proprioceptive deficits in knee OA.

Does knee osteoarthritis differentially modulate proprioceptive acuity in the frontal and sagittal planes of the knee?

OBJECTIVE

Impaired proprioception may alter joint loading and contribute to the progression of knee osteoarthritis (OA). Although frontal plane loading at the knee contributes to OA, proprioception and its modulation with OA in this direction have not been examined. The aim of this study was to assess knee proprioceptive acuity in the frontal and sagittal planes in patients with knee OA and healthy subjects. We hypothesized that proprioceptive acuity in both planes of movement will be decreased in patients with OA.

METHODS

The study group comprised 13 patients with knee OA and 14 healthy age-matched subjects. Proprioceptive acuity was assessed in varus, valgus, flexion, and extension using threshold to detection of passive movement (TDPM) tests. Repeated-measures analysis of variance was used to assess differences in TDPM values between the 2 groups and across movement directions. Linear regression analyses were performed to assess the correlation of the TDPM between and within planes of movement.

RESULTS

The TDPM was significantly higher (P<0.05) in the group with knee OA compared with the control group for all directions tested, indicating reduced proprioceptive acuity. Differences in the TDPM between groups were consistent across all movement directions, with mean differences as follows: for valgus, 0.94° (95% confidence interval [95% CI] 0.20-1.65°); for varus, 0.92° (95% CI 0.18-1.68°); for extension, 0.93° (95% CI 0.19-1.66°); for flexion, 1.11° (95% CI 0.38-1.85°). The TDPM measures across planes of movement were only weakly correlated, especially in the group with knee OA.

CONCLUSION

Consistent differences in the TDPM between the group of patients with knee OA and the control group across all movement directions suggest a global, not direction-specific, reduction in sensation in patients with knee OA.