Knee position error detection in closed and open kinetic chain tasks during concurrent cognitive distraction

The effects of toe direction on three-dimensional knee kinematics during closed kinetic chain exercise in patients with anterior cruciate ligament deficient knee

Background/Objective

Closed Kinetic Chain Exercise (CKC Ex) is a safe rehabilitation method for anterior cruciate ligament deficient (ACLD) and reconstructed knees. However, CKC Ex can be risky based on abnormal toe directions. The purpose was to investigate knee kinematics during CKC Ex under three toe directions in ACLD.

Methods

Twenty patients with unilateral ACL injury participated. The subjects performed five weight-bearing-static lunge tests on each limb under three toe directions, including 0 degrees (TN), 20 degrees (TI), and -20 degrees (TO). Three-dimensional knee kinematics were calculated using three-dimensional motion analysis system and were compared among three different toe directions.

Results

Among three different toe directions, peak values of knee valgus and external rotation on ACLD side were significantly larger in TO than in TN and TI. In addition, the total excursion in the coronal plane on ACLD side was significantly larger in TO than in TN and TI. Regarding the differences between ACLD and ACLI, peak values of internal rotation angle was significantly smaller in ACLD than in ACLI.

Conclusion

From the present results, tibial rotation and knee abduction were strongly affected by toe direction. When considering a safe rehabilitation, it would be better to avoid TI and TO in CKC Ex in patients with unilateral ACL injury.

Changes in Head and Neck Position Have a Greater Effect on Elbow Joint Position Sense in People With Whiplash-associated Disorders

BACKGROUND

It has been shown that perception of elbow joint position is affected by changes in head and neck position. Further, people with whiplash-associated disorders (WAD) present with deficits in upper limb coordination and movement.

OBJECTIVES

This study is aimed to determine whether the effect of changes in head position on elbow joint position error (JPE) is more pronounced in people with WAD, and to determine whether this is related to the participant's pain and anxiety levels.

METHODS

Nine people with chronic and disabling WAD and 11 healthy people participated in this experiment. The ability to reproduce a position at the elbow joint was assessed after changes in the position of the head and neck to 30 degrees , and with the head in the midline. Pain was monitored in WAD participants.

RESULTS

Absolute elbow JPE with the head in neutral was not different between WAD and control participants (P=0.5). Changes in the head and neck position increased absolute elbow JPE in the WAD group (P<0.05), but did not affect elbow JPE in the control group (P=0.4). There was a connection between pain during testing and the effect of changes in head position on elbow JPE (P<0.05).

DISCUSSION

Elbow JPE is affected by movement of the head and neck, with smaller angles of neck rotation in people with WAD than in healthy individuals. This observation may explain deficits in upper limb coordination in people with WAD, which may be due to the presence of pain or reduced range of motion in this population.

Do you know where your arm is if you think your head has moved?

Reproduction of a previously presented elbow position is affected by changes in head position. As movement of the head is associated with local biomechanical changes, the aim of the present study was to determine if illusory changes in head position could induce similar effects on the reproduction of elbow position. Galvanic vestibular stimulation (GVS) was applied to healthy subjects in supine lying. The stimulus was applied during the presentation of an elbow position, which the subject then reproduced without stimulation. In the first study, 13 subjects received 1.5 mA stimuli, which caused postural sway in standing, confirming that the firing of vestibular afferents was affected, but no illusory changes in head position were reported. In the second study, 13 subjects received 2.0-3.0 mA GVS. Six out of 13 subjects reported consistent illusory changes in head position, away from the side of the anode. In these subjects, anode right stimulation induced illusory left lateral flexion and elbow joint position error towards extension (p=0.03), while anode left tended to have the opposite effect (p=0.16). The GVS had no effect on error in subjects who did not experience illusory head movement with either 1.5 mA stimulus (p=0.8) or 2.0-3.0 mA stimulus (p=0.7). This study demonstrates that the accuracy of elbow repositioning is affected by illusory changes in head position. These results support the hypothesis that the perceived position of proximal body segments is used in the planning and performance of accurate upper limb movements.

Changes in head and neck position affect elbow joint position sense

Changes in the position of the head and neck have been shown to introduce a systematic deviation in the end-point error of an upper limb pointing task. Although previous authors have attributed this to alteration of perceived target location, no studies have explored the effect of changes in head and neck position on the perception of limb position. This study investigated whether changes in head and neck position affect a specific component of movement performance, that is, the accuracy of joint position sense (JPS) at the elbow. Elbow JPS was tested with the neck in four positions: neutral, flexion, rotation and combined flexion/rotation. A target angle was presented passively with the neck in neutral, after a rest period; this angle was reproduced actively with the head and neck in one of the test positions. The potential effects of distraction from head movement were controlled for by performing a movement control in which the head and neck were in neutral for the presentation and reproduction of the target angle, but moved into flexion during the rest period. The absolute and variable joint position errors (JPE) were greater when the target angle was reproduced with the neck in the flexion, rotation, and combined flexion/rotation than when the head and neck were in neutral. This study suggests that the reduced accuracy previously seen in pointing tasks with changes in head position may be partly because of errors in the interpretation of arm position.

Effects of experimentally-induced anterior knee pain on knee joint position sense in healthy individuals

PURPOSE

The ability to sense the position of limb segments is a highly specialised proprioceptive function important for control of movement. Abnormal knee proprioception has been found in association with several musculoskeletal pathologies but whether nociceptive stimulation can produce these proprioceptive changes is unclear. This study evaluated the effect of experimentally induced knee pain on knee joint position sense (JPS) in healthy individuals.

STUDY DESIGN

Repeated measures, within-subject design.

METHODS

Knee JPS was tested in 16 individuals with no history of knee pathology under three experimental conditions: baseline control, a distraction task and knee pain induced by injection of hypertonic saline into the infrapatellar fat pad. Knee JPS was measured using active ipsilateral limb matching responses at 20 degrees and 60 degrees flexion whilst non-weightbearing (NWB) and 20 degrees flexion single leg stance. During the tasks, the subjective perception of distraction and severity of pain were measured using 11-point numerical rating scales.

RESULTS

Knee JPS was not altered by acute knee pain in any of the positions tested. The distraction task resulted in poorer concentration, greater JPS absolute errors at 20 degrees NWB, and greater variability in errors during the WB tests. There were no significant correlations between levels of pain and changes in JPS errors. Changes in JPS with pain and distraction were inversely related to baseline knee JPS variable error in all test positions (r=-0.56 to -0.91) but less related to baseline absolute error.

CONCLUSION

Knee JPS is reduced by an attention-demanding task but not by experimentally induced pain.

The role of weightbearing in the clinical assessment of knee joint position sense

Knee joint position sense was assessed by active tests with active limb matching responses in supine lying and in unilateral weightbearing (WB) stance using (re)positioning of the whole limb whilst focusing on the knee, and in supine lying using (re)positioning confined to the knee. Following five tests at approximately 45 degrees knee flexion in all three test conditions, position sense was found to be significantly more accurate and reliable following the WB procedure. Possible explanations are, first, that during WB the subjects were more able to assist identification of the test positions using cues obtained during movement of the knee to and from these positions. Second, a larger volume of proprioceptive afferent information may have been derived from sources outside the examined knee, and even outside the examined limb. Whilst WB joint position sense assessments are more functional, the obtained results may not characterise the capacity of the proprioceptors in and around the examined (knee) joint. Since the WB and NWB results were not correlated, one procedure cannot be used to predict results from the others. Also, predominantly unilateral WB stance is often impractical for subjects with limited balance or WB pain.

The effects of joint angle and reliability on knee proprioception

PURPOSE

The purpose of this study was to examine the reliability and effects of knee angle on the detection and subsequent response to passive knee movement.

METHODS

Twenty college-aged male and 20 female volunteers were evaluated for proprioception by a newly developed perturbation test. Subjects were in a prone position on an isokinetic chair with their right lower leg attached to a freely moving resistance adapter. The knee was placed in a starting position of 15, 30, or 60 degrees of flexion. While relaxed, the knee was dropped into extension, and the subjects were instructed to "catch their leg" when movement was perceived. Five trials were completed at each angle, in a random order. An electrogoniometer was secured to the lateral portion of the knee in order to measure angular displacement after perturbation in two specific phases: detection (displacement from leg release to movement cessation) and response (displacement from movement cessation to peak knee flexion). A three-factor ANOVA (two repeated factors (knee angle and proprioception phase) and one between factor (gender)) was performed on the average and standard deviation of the five trials for significant main effects and interactions.

RESULTS

The results demonstrated a significant phase by angle interaction, and no gender effect. It was shown that at a more extended knee joint position (15 degrees), significantly less knee movement occurred before perception, followed by a greater response, than in a more flexed position (30 and 60 degrees).

CONCLUSION

The major findings of this study suggest that the detection of passive knee movement, and the subsequent voluntary response, may be dependent on joint angle. Considerations of the present method for proprioception assessment are warranted to enhance test-retest reliability.

Measurement of Knee-Joint-Position Sense in Women with Genu Recurvatum

Context:

Proprioception of the knee joint.

Objective:

To determine the difference in knee-joint-angle reproduction in women with and without genu recurvatum (GR).

Design:

Between-subjects.

Setting:

Clinic.

Subjects:

Twenty-four women divided into 2 groups according to their standing knee-extension angle.

Main Outcome Measures:

Each subject's ability to actively reproduce active positioning of 3 knee angles (10, 30, and 60°) was measured. Pearson correlation coefficients were calculated to determine correlation values for standing GR angle and absolute angular error (AAE). A1 -way repeated-measures MANOVA was computed to evaluate differences in group, angle, limb, and trial.

Results:

Standing GR angle correlated significantly to the AAE angle at 10° (r= .48). The high-recurvatum group consistently scored worse, with the highest error rate occurring at 10°.

Conclusion:

Individuals with GR might have diminished proprioceptive sense at end-range extension that could potentially lead to knee injury.