The association between muscle strength and activity limitations in patients with the hypermobility type of Ehlers–Danlos syndrome : the impact of proprioception

Purpose: The patients diagnosed with Ehlers-Danlos Syndrome Hypermobility Type (EDS-HT) are characterized by pain, proprioceptive inacuity, muscle weakness, potentially leading to activity limitations. In EDS-HT, a direct relationship between muscle strength, proprioception and activity limitations has never been studied. The objective of the study was to establish the association between muscle strength and activity limitations and the impact of proprioception on this association in EDS-HT patients. Methods: Twenty-four EDS-HT patients were compared with 24 controls. Activity limitations were quantified by Health Assessment Questionnaire (HAQ), Six-Minute Walk test (6MWT) and 30-s chair-rise test (30CRT). Muscle strength was quantified by handheld dynamometry. Proprioception was quantified by movement detection paradigm. In analyses, the association between muscle strength and activity limitations was controlled for proprioception and confounders. Results: Muscle strength was associated with 30CRT (r = 0.67, p = <0.001), 6MWT (r = 0.58, p = <0.001) and HAQ (r = 0.63, p = <0.001). Proprioception was associated with 30CRT (r = 0.55, p <0.001), 6MWT (r = 0.40, p = <0.05) and HAQ (r = 0.46, p < 0.05). Muscle strength was found to be associated with activity limitations, however, proprioceptive inacuity confounded this association. Conclusions: Muscle strength is associated with activity limitations in EDS-HT patients. Joint proprioception is of influence on this association and should be considered in the development of new treatment strategies for patients with EDS-HT. Implications for rehabilitation : Reducing activity limitations by enhancing muscle strength is frequently applied in the treatment of EDS-HT patients. Although evidence regarding treatment efficacy is scarce, the current paper confirms the rationality that muscle strength is an important factor in the occurrence of activity limitations in EDS-HT patients. Although muscle strength is the most dominant factor that is associated with activity limitations, this association is confounded by proprioception. In contrast to common belief proprioception was not directly associated with activity limitations but confounded this association. Controlling muscle strength on the bases of proprioceptive input may be more important for reducing activity limitations than just enhancing sheer muscle strength

Space adaptation syndrome experiments (8-IML-1)

A set of seven experiments will study adaptation of the human nervous system to weightlessness. Particular emphasis will be placed on the vestibular and proprioceptive systems. The experiments are as follows: the sled/H-reflex; rotation/vestibulo-ocular reflex; the visual stimulator experiment; proprioception (relaxed) experiment; proprioception (active) experiment; proprioception (illusion) experiment; and tactile acuity

Comparison of Ankle Proprioception Between Pregnant and Non Pregnant Women

Pregnant women report falls especially during their third trimester. Physiological changes along with ligament laxity can affect the joint proprioception in this population. This study was conducted to compare the ankle proprioception between pregnant and non pregnant women. Thirty pregnant and 30 non pregnant women were included in the study and the position of ankles were recorded by a digital camera placed 60 cms away from the feet of the subject. UTHSCSA Image tool software version 3.0. was used to measure the difference between the initial and the final angle. The median repositioning error in the pregnant group was 11.6 (7.6, 12.4) degrees and the median repositioning error in the non-pregnant group was 4.2 (2.1, 6.3) degrees. There was a statistically significant difference in ankle joint proprioception between pregnant and non pregnant women

EEG and EMG Sensorimotor Measurements to Assess Proprioception Following ACL Reconstruction

The Anterior Cruciate Ligament (ACL) is the primary source of rotational stability in the knee by preventing the tibia from sliding in front of the femur. When the ACL is torn, it typically must be repaired through reconstructive surgery which results in proprioceptive deficiencies in the knee. Proprioception plays an important role in understanding where one’s knee is in space, sensing movement and reacting accordingly. This study examines an alternative method of measuring proprioceptive responses to a stimulus (motion) by using electromyogram (EMG) and electroencephalogram (EEG) signals to observe muscle and brain activity. Two participants (one with an ACL reconstruction and a second with healthy knees) were tested three times over a six week period. Repeated measures allowed for an initial examination of how proprioception may vary over time in an individual with healthy knees and with an ACL reconstruction. This measurement strategy can examine the process of proprioception recovery after an ACL reconstruction. It has the potential to help physicians and physical therapists decide when a person can return to normal or strenuous activity as well as provide insight into whether uninjured patients have a proprioceptive deficit which may indicate an increased risk of injury

The effects of Tai Chi on peripheral somatosensation, balance, and fitness in Hispanic older adults with type 2 diabetes:a pilot and feasibility study

Peripheral neuropathy and loss of somatosensation in older adults with type 2 diabetes can increase risk of falls and disability. In nondiabetic older adult population Tai Chi has been shown to enhance balance and fitness through improvements in somatosensation and neuromuscular control, and it is unclear if Tai Chi would elicit similar benefits in older adults with diabetes. Therefore, the purpose of this study was to investigate the effects of an 8-week, three-hour-per-week Tai Chi intervention on peripheral somatosensation in older adults with type 2 diabetes. Participants were eight Hispanic older adults with type 2 diabetes who participated in the Tai Chi intervention and a convenience sample of Hispanic older adults as a referent group. Baseline and postintervention assessments included ankle proprioception, foot tactile sense, plantar pressure distribution, balance, and fitness. After intervention, older adults with type 2 diabetes showed significant improvements in ankle proprioception and fitness and decreased plantar pressure in the forefoot, with no statistical effect noted in balance or tactile sensation. Study results suggest that Tai Chi may be beneficial for older adults with diabetes as it improves ankle proprioception; however, study findings need to be confirmed in a larger sample size randomized controlled trial

Manual Matching Of Perceived Surface Orientation Is Affected By Arm Posture: Evidence Of Calibration Between Proprioception And Visual Experience In Near Space

Proprioception of hand orientation (orientation production using the hand) is compared with manual matching of visual orientation (visual surface matching using the hand) in two experiments. In experiment 1, using self-selected arm postures, the proportions of wrist and elbow flexion spontaneously used to orient the pitch of the hand (20 and 80%, respectively) are relatively similar across both manual matching tasks and manual orientation production tasks for most participants. Proprioceptive error closely matched perceptual biases previously reported for visual orientation perception, suggesting calibration of proprioception to visual biases. A minority of participants, who attempted to use primarily wrist flexion while holding the forearm horizontal, performed poorly at the manual matching task, consistent with proprioceptive error caused by biomechanical constraints of their self-selected posture. In experiment 2, postural choices were constrained to primarily wrist or elbow flexion without imposing biomechanical constraints (using a raised forearm). Identical relative offsets were found between the two constraint groups in manual matching and manual orientation production. The results support two claims: (1) manual orientation matching to visual surfaces is based on manual proprioception and (2) calibration between visual and proprioceptive experiences guarantees relatively accurate manual matching for surfaces within reach, despite systematic visual biases in perceived surface orientation

Do Balance Demands Induce Shifts in Visual Proprioception in Crawling Infants?

The onset of hands-and-knees crawling during the latter half of the first year of life heralds pervasive changes in a range of psychological functions. Chief among these changes is a clear shift in visual proprioception, evident in the way infants use patterns of optic flow in the peripheral field of view to regulate their postural sway. This shift is thought to result from consistent exposure in the newly crawling infant to different patterns of optic flow in the central field of view and the periphery and the need to concurrently process information about self-movement, particularly postural sway, and the environmental layout during crawling. Researchers have hypothesized that the demands on the infant's visual system to concurrently process information about self-movement and the environment press the infant to differentiate and functionalize peripheral optic flow for the control of balance during locomotion so that the central field of view is freed to engage in steering and monitoring the surface and potentially other tasks. In the current experiment, we tested whether belly crawling, a mode of locomotion that places negligible demands on the control of balance, leads to the same changes in the functional utilization of peripheral optic flow for the control of postural sway as hands-and-knees crawling. We hypothesized that hands-and-knees crawlers (n = 15) would show significantly higher postural responsiveness to movements of the side walls and ceiling of a moving room than same-aged pre-crawlers (n = 19) and belly crawlers (n = 15) with an equivalent amount of crawling experience. Planned comparisons confirmed the hypothesis. Visual-postural coupling in the hands-and-knees crawlers was significantly higher than in the belly crawlers and pre-crawlers. These findings suggest that the balance demands associated with hands-and-knees crawling may be an important contributor to the changes in visual proprioception that have been demonstrated in several experiments to follow hands-and-knees crawling experience. However, we also consider that belly crawling may have less potent effects on visual proprioception because it is an effortful and attention-demanding mode of locomotion, thus leaving less attentional capacity available to notice changing relations between the self and the environment

Bodily awareness and novel multisensory features

According to the decomposition thesis, perceptual experiences resolve without remainder into their different modality-specific components. Contrary to this view, I argue that certain cases of multisensory integration give rise to experiences representing features of a novel type. Through the coordinated use of bodily awareness—understood here as encompassing both proprioception and kinaesthesis—and the exteroceptive sensory modalities, one becomes perceptually responsive to spatial features whose instances couldn’t be represented by any of the contributing modalities functioning in isolation. I develop an argument for this conclusion focusing on two cases: 3D shape perception in haptic touch and experiencing an object’s egocentric location in crossmodally accessible, environmental space