Proprioceptive Role Research Articles

Beyond the Dorsal Column Medial Lemniscus in Proprioception and Stroke: A White Matter Investigation.

Proprioceptive deficits are common following stroke, yet the white matter involved in proprioception is poorly understood. Evidence suggests that multiple cortical regions are involved in proprioception, each connected by major white matter tracts, namely: Superior Longitudinal Fasciculus (branches I, II and III), Arcuate Fasciculus and Middle Longitudinal Fasciculus (SLF I, SLF II, SLF III, AF and MdLF respectively). However, direct evidence on the involvement of these tracts in proprioception is lacking. Diffusion imaging was used to investigate the proprioceptive role of the SLF I, SLF II, SLF III, AF and MdLF in 26 participants with stroke, and seven control participants without stroke. Proprioception was assessed using a robotic Arm Position Matching (APM) task, performed in a Kinarm Exoskeleton robotic device. Lesions impacting each tract resulted in worse APM task performance. Lower Fractional Anisotropy (FA) was also associated with poorer APM task performance for the SLF II, III, AF and MdLF. Finally, connectivity data surrounding the cortical regions connected by each tract accurately predicted APM task impairments post-stroke. This study highlights the importance of major cortico-cortical white matter tracts, particularly the SLF III and AF, for accurate proprioception after stroke. It advances our understanding of the white matter tracts responsible for proprioception.

Effects of dry needling of the obliquus capitis inferior on sensorimotor control and cervical mobility in people with neck pain: A double-blind, randomized sham-controlled trial

BackgroundImpairments of sensorimotor control relating to head and eye movement control and postural stability are often present in people with neck pain. The upper cervical spine and particularly the obliquus capitis inferior (OCI) play an important proprioceptive role; and its impairment may alter cervical sensorimotor control. Dry needling (DN) is a valid technique to target the OCI. ObjectivesTo investigate if a single DN session of the OCI muscle improves head and eye movement control-related outcomes, postural stability, and cervical mobility in people with neck pain. MethodsForty people with neck pain were randomly assigned to receive a single session of DN or sham needling of the OCI. Cervical joint position error (JPE), cervical movement sense, standing balance and oculomotor control were examined at baseline, immediately post-intervention, and at one-week follow-up. Active cervical rotation range of motion and the flexion rotation test were used to examine the global and upper cervical rotation mobility, respectively. ResultsLinear mixed-models revealed that the DN group showed a decrease of JPE immediately post-intervention compared to the sham group (mean difference [MD]= -0.93°; 95% confidence interval [CI]: -1.85, -0.02) which was maintained at one-week follow-up (MD= -1.64°; 95%CI: -2.85, -0.43). No effects on standing balance or cervical movement sense were observed in both groups. Upper cervical mobility showed an increase immediately after DN compared to the sham group (MD= 5.14°; 95%CI: 0.77, 9.75) which remained stable at one-week follow-up (MD= 6.98°; 95%CI: 1.31, 12.40). Both group showed an immediate increase in global cervical mobility (MD= -0.14°; 95%CI: -5.29, 4.89). ConclusionThe results from the current study suggest that a single session of DN of the OCI reduces JPE deficits and increases upper cervical mobility in patients with neck pain. Future trials should examine if the addition of this technique to sensorimotor control training add further benefits in the management of neck pain.

Achieving functional neuronal dendrite structure through sequential stochastic growth and retraction.

Class I ventral posterior dendritic arborisation (c1vpda) proprioceptive sensory neurons respond to contractions in the Drosophila larval body wall during crawling. Their dendritic branches run along the direction of contraction, possibly a functional requirement to maximise membrane curvature during crawling contractions. Although the molecular machinery of dendritic patterning in c1vpda has been extensively studied, the process leading to the precise elaboration of their comb-like shapes remains elusive. Here, to link dendrite shape with its proprioceptive role, we performed long-term, non-invasive, in vivo time-lapse imaging of c1vpda embryonic and larval morphogenesis to reveal a sequence of differentiation stages. We combined computer models and dendritic branch dynamics tracking to propose that distinct sequential phases of stochastic growth and retraction achieve efficient dendritic trees both in terms of wire and function. Our study shows how dendrite growth balances structure-function requirements, shedding new light on general principles of self-organisation in functionally specialised dendrites.

Evolutionary Variation and Biomechanics of the Avian Furcula

The avian wishbone, or furcula, serves as the cranial‐most attachment of the m. pectoralis in most birds, variably connects to the coracoid and sternum, and is morphologically diverse across the clade. Furcula shape and microstructure covary with flight style, suggesting its functional importance to flight. Several overlapping hypotheses have been proposed for furcular morphology, such as aiding wing protraction or increasing ventilation efficiency, but the bone remains an enigmatic part of the avian pectoral girdle. In particular, we have little understanding of how furcula morphology and material properties relates to other pectoral structures, including flight muscles such as m. sternocoracoideus. Despite the hypothesized significance of the furcula in the origin of flight and diversification of flight styles, further work needs to be done to understand its functional properties among extant taxa.In order to explore variation in the furcula and pectoral structures relative to flight style, we studied members of 12 bird families using a three‐pronged approach. Specifically, we examined 1) the shape of the furcula in relation to its in situ orientation using non‐contrast computed tomography (CT), 2) the relative size of m. pectoralis and its subdivisions using contrast‐enhanced CT (DiceCT), and 3) the functional potential of the m. sternocoracoideus to effect or respond to furcula deformation using muscle lever analysis, material properties testing, and muscle spindle histology.We found substantial differences in furcular orientation, muscular proportions, and furcula material properties across the sample. Whereas earlier studies found a relatively weak correlation between flight style and furcula shape, we found that accounting for in situ furcula orientation improves the correlation between shape and flight style. Birds with more anteriorly‐curved furculae also show a relatively larger cranial division of m. pectoralis. These results support the hypothesis that furcula curvature mediates the protractive capability of m. pectoralis during downstroke. Notably, muscular differences between furculate and afurculate species of parrots (Psittaciformes) were insignificant despite similar flight styles, suggesting that other musculoskeletal structures may take on the functional role of the furcula in certain clades. We also found little variation in m. sternocoracoideus regarding spindle density and muscle moments about the coracosternal joint. The small size and suboptimal location of m. sternocoracoideus suggests that it serves a proprioceptive role, perhaps necessary to assess interglenoid distance during flight, rather than to laterally spread the furcula via the coracoids. Nevertheless, its morphological disparity across our sample remains unexplained.Support or Funding InformationUniversity of Missouri Life Sciences Fellowship

Innervation of the hip joint capsular complex: A systematic review of histological and immunohistochemical studies and their clinical implications for contemporary treatment strategies in total hip arthroplasty.

The hip joint capsule contributes to the stability of the hip joint and lower extremity, yet this structure is incised and often removed during total hip arthroplasty (THA). Increasing incidence of osteoarthritis is accompanied by a dramatic rise in THAs over the last few decades. Consequently, to improve this treatment, THA with capsular repair has evolved. This partial restoration of physiological hip stability has resulted in a substantial reduction in post-operative dislocation rates compared to conventional THA without capsular repair. A further reason for the success of this procedure is thought to be the preservation of the innervation of the capsule. A systematic review of studies investigating the innervation of the hip joint capsular complex and pseudocapsule with histological techniques was performed, as this is not well established. The literature was sought from databases Amed, Embase and Medline via OVID, PubMed, ScienceDirect, Scopus and Web of Science; excluding articles without a histological component and those involving animals. A total of 21 articles on the topic were identified. The literature indicates two primary outcomes and potential clinical implications of the innervation of the capsule. Firstly, a role in the mechanics of the hip joint, as mechanoreceptors may be present in the capsule. However, the nomenclature used to describe the distribution of the innervation is inconsistent. Furthermore, the current literature is unable to reliably confirm the proprioceptive role of the capsule, as no immunohistochemical study to date has reported type I-III mechanoreceptors in the capsule. Secondly, the capsule may play a role in pain perception, as the density of innervation appears to be altered in painful individuals. Also, increasing age may indicate requirements for different strategies to surgically manage the hip capsule. However, this requires further study, as well as the role of innervation according to sex, specific pathology and other morphometric variables. Increased understanding may highlight the requirement for capsular repair following THA, how this technique may be developed and the contribution of the capsule to joint function and stability.

Study of the Nerve Endings and Mechanoreceptors of the Anterolateral Ligament of the Knee

To describe the morphology and distribution of the anterolateral ligament of the knee (ALL) nerve endings, aiming to understand the interaction between the proprioceptive system and knee mechanics. Twenty ALLs were obtained from fresh frozen cadavers. The ligaments were measured, weighed, and cut. Sections (10μm) were prepared in hematoxylin and eosin-stained slides to analyze tissue integrity, and 50-μm sections were subjected to immunofluorescence with the protein gene product 9.5 as primary antibody and Alexa Fluor 488 as secondary antibody, followed by microscopic analysis. The ALL was identified in 100% of the dissections, exhibiting a mean (±standard deviation) length of 4.0 ± 0.4cm, a mean width of 5.5 ± 0.8mm, and a mean weight of 0.9 ± 0.2g. The histological sections in hematoxylin and eosin showed dense, well-organized collagen and the presence of vascular tissue. All the specimens analyzed contained type I (Ruffini-like) mechanoreceptors and free nerve endings (type IV), varying from parallel to intertwined fibers. Unclassified nerve endings with different irregular shapes were also found. The neural elements occupied 0.6% ± 0.3% of the ligament area, and most were observed near the origin of ALL insertions. The ALL exhibits a peripheral nerve structure, primarily type I and IV mechanoreceptors. These findings suggest that the ALL is important for the proprioception and anterolateral stabilization of the knee. It is important to understand ALL innervation and infer how an injury could compromise the proprioceptive role of the lateral compartment, as the ligaments contribute dynamically to stability through proprioceptive control of muscle forces. The findings confirm that the ALL is highly innervated by mechanoreceptors and may have a proprioceptive role in conjunction with the lateral collateral ligament in the lateral region of the knee.

The plantaris muscle: too important to be forgotten. A review of evolution, anatomy, clinical implications and biomechanical properties.

Plantaris muscle (lat. musculus plantaris) is a fusiform muscle of the superficial posterior leg compartment, characterized with a small muscle belly and very long and slender tendon. Many anatomical variations of plantaris muscle have been reported previously, including its inconstancy. Evolutional studies strongly suggest that plantaris muscle is a rudimentary muscle that plays minor role in gait biomechanics. However, plantaris muscle seems to have very important proprioceptive role since it has very high density of muscle spindles. Clinically, plantaris muscle is involved in differential diagnosis of posterior leg pain and several pathological entities such as: plantaris muscle rupture, non-insertional Achilles tendinopathy and popliteal artery compression syndrome. Different surgical specialties have recognized plantaris muscle tendon as a valuable graft. However, literature on plantaris muscle tendon biomechanical properties is rather scant and inconsistent with several limitations for proper data comparison and interpretation. Further comparative studies are needed to properly define biomechanical properties of plantaris muscle tendon grafts for various ligament and tendon reconstructive procedures.

Body ownership and a new proprioceptive role for muscle spindles

Knowledge of which body parts belong to us is referred to as the sense of body ownership. There is increasing evidence that this important aspect of human proprioception is highly malleable. Research into ownership of individual body parts was stimulated by Botvinick and Cohen's rubber-hand illusion (Nature 391,1998, 756), which demonstrated that an artificial body part can be incorporated in one's body representation and can cause real body parts to be sensed erroneously. Here, we review key studies that have advanced our understanding of the sense of body ownership, including the important role played by multisensory integration and spatiotemporal congruence of sensory signals. We also discuss our recent discovery that body ownership can be induced in response to movement stimuli by signals from a single class of sensory receptor, namely muscle spindles.

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

A cadaveric study of the anterolateral ligament: re-introducing the lateral capsular ligament.

The purpose of this study was to verify and characterize the anatomical properties of the anterolateral capsule, with the aim of establishing a more accurate anatomical description of the anterolateral ligament (ALL). Furthermore, microscopic analysis of the tissue was performed to determine whether the ALL can morphologically be classified as ligamentous tissue, as well as reveal any potential functional characteristics. Three different modalities were used to validate the existence of the ALL: magnetic resonance imagining (MRI), anatomical dissection, and histological analysis. Ten fresh-frozen cadaveric knee specimens underwent MRI, followed by anatomical dissection which allowed comparison of MRI to gross anatomy. Nine additional fresh-frozen cadaveric knees (19 total) were dissected for a further anatomical description. Four specimens underwent H&E staining to look at morphological characteristics, and one specimen was analysed using immunohistochemistry to locate peripheral nervous innervation. The ALL was found in all ten knees undergoing MRI and all nineteen knees undergoing anatomical dissection, with MRI being able to predict its corresponding anatomical dissection. The ALL was found to have bone-to-bone attachment points from the lateral femoral epicondyle to the lateral tibia, in addition to a prominent meniscal attachment. Histological sectioning showed ALL morphology to be characteristic of ligamentous tissue, having dense, regularly organized collagenous bundles. Immunohistochemistry revealed a large network of peripheral nervous innervation, indicating a potential proprioceptive role. From this study, the ALL is an independent structure in the anterolateral compartment of the knee and may serve a proprioceptive role in knee mechanics.

Distribution of sensory nerve endings around the human sinus tarsi: a cadaver study

The aim of this study was to analyse the pattern of sensory nerve endings and blood vessels around the sinus tarsi. The superficial and deep parts of the fat pads at the inferior extensor retinaculum (IER) as well as the subtalar joint capsule inside the sinus tarsi from 13 cadaver feet were dissected. The distribution of the sensory nerve endings and blood vessels were analysed in the resected specimens as the number per cm(2) after staining with haematoxylin-eosin, S100 protein, low-affinity neurotrophin receptor p75, and protein gene product 9.5 using the classification of Freeman and Wyke. Free nerve endings were the predominant sensory ending (P<0.001). Ruffini and Golgi-like endings were rarely found and no Pacini corpuscles were seen. Significantly more free nerve endings (P<0.001) and blood vessels (P=0.01) were observed in the subtalar joint capsule than in the superficial part of the fat pad at the IER. The deep part of the fat pad at the IER had significantly more blood vessels than the superficial part of the fat pad at the IER (P=0.012). Significantly more blood vessels than free nerve endings were seen in all three groups (P<0.001). No significant differences in distribution were seen in terms of right or left side, except for free nerve endings in the superficial part of the fat pad at the IER (P=0.003). A greater number of free nerve endings correlated with a greater number of blood vessels. The presence of sensory nerve endings between individual fat cells supports the hypothesis that the fat pad has a proprioceptive role monitoring changes and that it is a source of pain in sinus tarsi syndrome due to the abundance of free nerve endings.

Tibialis anterior muscle fascicle dynamics adequately represent postural sway during standing balance

To maintain a stable, upright posture, the central nervous system (CNS) must integrate sensory information from multiple sources and subsequently generate corrective torque about the ankle joint. Although proprioceptive information from the muscles that cross this joint has been shown to be vital in this process, the specific source of this information remains questionable. Recent research has been focused on the potential role of tibialis anterior (TA) muscle during standing, largely due to the lack of modulation of its activity throughout the sway cycle. Ten young, healthy subjects were asked to stand normally under varying conditions, for periods of 60 s. During these trials, intramuscular electromyographic (EMG) activity and the fascicle length of three distinct anatomical regions of TA were sampled synchronously with kinematic data regarding sway position. In the quiet standing conditions, TA muscle activity was unmodulated and fascicle length changes in each region were tightly coupled with changes in sway position. In the active sway condition, more EMG activity was observed in TA and the fascicle length changes were decoupled from sway position. No regional specific differences in correlation values were observed, contrasting previous observations. The ability of the fascicles to follow sway position builds upon the suggestion that TA is well placed to provide accurate, straightforward sensory information to the CNS. As previously suggested, through reciprocal inhibition, afferent information from TA could help to regulate plantar flexor torque at relevant phases of the sway cycle. The proprioceptive role of TA appears to become complicated during more challenging conditions.

Relationships Between Joint Motion and Facet Joint Capsule Strain During Cat and Human Lumbar Spinal Motions

Objective The lumbar facet joint capsule (FJC) is innervated with mechanically sensitive neurons and is thought to contribute to proprioception and pain. Biomechanical investigations of the FJC have commonly used human cadaveric spines, whereas combined biomechanical and neurophysiological studies have typically used nonhuman animal models. The purpose of this study was to develop mathematical relationships describing vertebral kinematics and FJC strain in cat and human lumbar spine specimens during physiological spinal motions to facilitate future efforts at understanding the mechanosensory role of the FJC. Methods Cat lumbar spine specimens were tested during extension, flexion, and lateral bending. Joint kinematics and FJC principal strain were measured optically. Facet joint capsule strain–intervertebral angle (IVA) regression relationships were established for the 3 most caudal lumbar joints using cat (current study) and human (prior study) data. The FJC strain–IVA relationships were used to estimate cat and human spine kinematics that corresponded to published sensory neuron response thresholds (5% and 10% strain) for low-threshold mechanoreceptors. Results Significant linear relationships between IVA and strain were observed for both human and cat during motions that produced tension in the FJCs ( P < .01). During motions that produced tension in the FJCs, the models predicted that FJC strain magnitudes corresponding to published sensory neuron response thresholds would be produced by IVA magnitudes within the physiological range of lumbar motion. Conclusions Data from the current study support the proprioceptive role of lumbar spine FJC and low-threshold mechanoreceptive afferents and can be used in interpreting combined neurophysiological and biomechanical studies of cat lumbar spines.

Illusory movements of a phantom hand grade with the duration and magnitude of motor commands

The senses of limb movement and position are critical for accurate control of movement. Recent studies show that central signals of motor command contribute to the sense of limb position but it is not clear whether such signals influence the distinctly different sense of limb movement. Nine subjects participated in two experiments in which we inflated a cuff around their upper arm to produce an ischaemic block, paralysing and anaesthetising the forearm, wrist and hand. This produces an experimental phantom wrist and hand. With their arm hidden from view subjects were asked to make voluntary efforts with their blocked wrist. In the first experiment, efforts were 20 and 40% of maximum and were 2 and 4 s in duration. The second experiment used 1 and 5 s efforts of 5 and 50% of maximum. Subjects signalled perceived movements of their phantom wrist using a pointer. All subjects reported clear perceptions of movement of their phantom hand for all levels and durations of effort. On average, subjects perceived their phantom wrist to move between 16.4 +/- 3.3 deg (mean +/- 95% confidence interval (CI)) and 30.2 +/- 5.4 deg in the first experiment and between 10.3 +/- 3.5 and 38.6 +/- 6.7 deg in the second. The velocity of the movements and total displacement of the phantom graded with the level of effort, and the total displacement also graded with duration. Hence, we have shown that motor command signals have a novel proprioceptive role in the perception of movement of human joints.

The Ankle Retinacula: Morphological Evidence of the Proprioceptive Role of the Fascial System

Study Design: Research report. Objectives: To evaluate the anatomical characteristics of the ankle retinacula and their relationship with the fasciae and muscles in healthy subjects and in patients with ankle sprain outcomes. Background: The role of the retinacula in proprioception has begun to emerge, but without clear anatomical bases or descriptions of their possible damage in patients with ankle sprain outcomes. Methods: Dissection, histological and immunohistochemical analysis of 27 legs. An in vivo radiological study by MRI was also performed on 7 healthy volunteers, 17 patients with outcomes of ankle sprain, and 3 amputated legs. Results: The retinacula are thickenings of the deep fascia presenting bone or muscular connections. They are formed of 2–3 layers of parallel collagen fibre bundles, densely packaged with a little loose connective tissue, without elastic fibres but many nervous fibres and corpuscles. By MRI, the retinacula appeared as low-signal-intensity bands with a mean thickness of 1 mm. In patients with outcomes of ankle sprain, MR findings were abnormal retinacula thickness, signal intensity, and full-thickness gap. Discussion: The retinacula are not static structures for joint stabilisation, like the ligaments, but a specialisation of the fascia for local spatial proprioception of the movements of foot and ankle. Their anatomical variations and accessory bundles may be viewed as morphological evidence of the integrative role of the fascial system in peripheral control of articular motility.

Proprioception of the Wrist Following Posterior Interosseous Sensory Neurectomy

The posterior interosseous sensory nerve innervates the dorsal capsule of the wrist, which may provide nociceptive and proprioceptive sensation. Posterior interosseous sensory neurectomy (PISN) is commonly used as a primary or adjunctive procedure to provide wrist analgesia for a variety of wrist conditions. Currently, there is little information in the literature regarding the proprioceptive role of the posterior interosseous sensory nerve and the resultant effects of PISN on wrist proprioception. The purpose of our investigation was to examine the effect of PISN on wrist proprioception. For 23 consecutive patients who had posterior interosseous sensory neurectomy, proprioception of their surgical wrists was compared to their nonsurgical wrists as well as to the normal wrists of 23 healthy volunteers. Using a custom testing device, wooden dowels were used to set subjects' wrists at specific angles within the testing jig, and then subjects were asked to mimic the position with their other hand at the following angles: neutral (0 degrees ), flexion (20 degrees , 40 degrees , 60 degrees ), extension (20 degrees , 40 degrees , 60 degrees ), 10 degrees of radial deviation, and 10 degrees of ulnar deviation. The following statistical comparisons were made:(1) patients' surgical versus controls' assessed wrists and(2) patients' surgical wrists versus patients' nonsurgical wrists. There were no statistically significant differences in wrist proprioception except in 40 degrees of extension with more accurate estimations by surgical wrists when compared to control wrists. Posterior interosseous sensory neurectomy does not appear to be associated with decreased proprioception of the wrist as measured by a custom testing device. Therapeutic IV.

Long-term results of lunocapitate arthrodesis with scaphoid excision for SLAC and SNAC wrists

When treating the degenerative arthritis that follows scapholunate instability or scaphoid pseudarthrosis, excision of the scaphoid must be combined with a stabilisation of the midcarpal joint. Two alternatives have been proposed for that purpose: fusing the lunate, triquetrum, capitate and hamate (four corner fusion), 4CF; or limiting the arthrodesis to the lunate and capitate, preserving or excising the triquetrum. Previous reports have attributed a high level of complications to lunocapitate arthrodesis, mainly in respect of nonunion. We have reviewed 17 patients who had been treated with a lunocapitate fusion, after an 8 to 12-year follow-up period, and found similar results compared with 4CF, even with a major degree of motion in ulnar-radial deviation. Recent work on the innervation of the radiotriquetral ligaments has given relevance to the preservation of lunotriquetral motion in maintaining proprioception. Also if the triquetrum is excised to gain more motion, the proprioceptive role of the radiotriquetral ligaments is compromised.

Local subcutaneous and muscle pain impairs detection of passive movements at the human thumb

Activity in both muscle spindle endings and cutaneous stretch receptors contributes to the sensation of joint movement. The present experiments assessed whether muscle pain and subcutaneous pain distort proprioception in humans. The ability to detect the direction of passive movements at the interphalangeal joint of the thumb was measured when pain was induced experimentally in four sites: the flexor pollicis longus (FPL), the subcutaneous tissue overlying this muscle, the flexor carpi radialis (FCR) muscle and the subcutaneous tissue distal to the metacarpophalangeal joint of thumb. Tests were conducted when pain was at a similar subjective intensity. There was no significant difference in the ability to detect flexion or extension under any painful or non-painful condition. The detection of movement was significantly impaired when pain was induced in the FPL muscle, but pain in the FCR, a nearby muscle that does not act on the thumb, had no effect. Subcutaneous pain also significantly impaired movement detection when initiated in skin overlying the thumb, but not in skin overlying the FPL muscle in the forearm. These findings suggest that while both muscle and skin pain can disturb the detection of the direction of movement, the impairment is site-specific and involves regions and tissues that have a proprioceptive role at the joint. Also, pain induced in FPL did not significantly increase the perceived size of the thumb. Proprioceptive mechanisms signalling perceived body size are less disturbed by a relevant muscle nociceptive input than those subserving movement detection. The results highlight the complex relationship between nociceptive inputs and their influence on proprioception and motor control.

Technique of Arthroscopic Anterior Cruciate Ligament Reconstruction With Preserved Residual Fibers as a Graft Envelope

ABSTRACT The preservation of the residual structure of the torn anterior cruciate ligament (ACL) stump during ACL reconstruction continues to engender controversy. Studies have shown that the residual ACL fibers within the stump may contribute to restore the proprioceptive function after ACL reconstruction. Proper selection of cases with sufficient residual ACL stump structure and surgical technique is crucial to regain the mechanical and proprioceptive role of the ACL and to prevent the development of cyclops lesion. This paper will focus on the surgical techniques in ACL reconstruction with the goal of preserving the residual ACL stump as a graft envelope.

Putative proprioceptive function of the pelvic ligaments: Biomechanical and histological studies

The sacrospinous (SS) and sacrotuberous (ST) ligaments of the pelvic ring are known as mechanical stabilisers of the pelvic girdle, primarily against rotational forces in the sagittal and horizontal planes. Earlier studies, however, raised the possibility that ST/SS ligaments possess significant proprioceptive function, while the mechanical role of these ligaments in maintaining the structural integrity of the pelvis is of less importance. The aim of this study is to determine whether the function of these ligaments is strictly to provide mechanical stability or if they have any additional functional properties, i.e., proprioception. In order to reveal the function of the SS/ST ligaments, biomechanical studies of cadaver pelvis were used along with the histological analysis of the ligaments. Following measurements to determine the accurate mechanical role of the pelvic ligaments, the strength of these ligaments was significantly less than we earlier expected. For this reason other functions of the SS/ST ligaments were considered, including the proprioceptive role. Indeed, histological studies revealed ramifying nerve terminals in the SS/ST ligaments. These terminals may represent the morphological substrate of the proprioceptive function associated with the ligaments. Our studies revealed that SS/ST ligaments might have a significant proprioceptive function providing information of the position of the pelvis. Consequently, the mechanical role of the ligaments in maintaining the structural integrity of the pelvis may be significantly less than previously assumed. Understanding the function of the SS/ST ligaments is crucial for providing more precise guidelines for patient management with injuries to the posterior pelvic region.