scholarly journals The effect of voluntary head movements on postural kinetics in the standing cat

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8186
Author(s):  
Yang Song ◽  
Meizi Wang ◽  
Julien Steven Baker ◽  
Yaodong Gu

Background Although the postural instability accompanying bilateral vestibular loss in human and quadrupeds during lateral head movements are well-known, it is still unclear whether or not lateral head turns would indeed activate the postural control system to maintain balance. This study aimed to examine the kinetic parameters in freely standing intact cats during head movements in order to further answer the above question. Methods Six intact cats were trained to stand, unrestrained on a force plate and perform voluntary head movements to the left and right positions in response to visual cues. Each trial was divided into two phases, quiet standing with the cat’s head maintaining a straight forward and lateral head position after voluntary head movements. Kinetic parameters including peak pressure and contact area under each limb as well as center of pressure (COP) displacements of the whole body were measured. Results Compared to the neutral head position, peak pressure and contact area of the left head position were significantly smaller for the left forelimb while greatly larger for the right forelimb. An exact opposite case of peak pressure and contact area in the forelimbs was found between the right and neutral head positions. In addition, the COP displacements altered oppositely to the head movements, and presented a significantly right shift in the left position and a significantly left shift in the right position. Conclusion These results demonstrate that the lateral displacement of the head in standing intact cats does activate the postural adjustment to maintain balance, which is consistent with the concept that vestibular input can contribute to postural balance during voluntary head turns.

2008 ◽  
Vol 98 (4) ◽  
pp. 261-267 ◽  
Author(s):  
Erin E. Klein ◽  
Ryan T. Crews ◽  
Stephanie C. Wu ◽  
James S. Wrobel ◽  
David G. Armstrong

Background: Exercise has not been studied extensively in persons with active neuropathic diabetic foot wounds, primarily because a device does not exist that allows patients to exercise while sufficiently off-loading pressure at the ulcer site. The purpose of this project was to demonstrate a device that reduces cycling plantar forefoot pressure. Methods: Ten healthy participants rode a recumbent bicycle under three cycling conditions. While the left foot interaction remained constant with a standard gym shoe and pedal, the right foot was exposed to a control condition with standard gym shoe and pedal, gym shoe and specialized cleat, and gym shoe with an off-loading insole and specialized cleat. Pressure and contact area of the plantar aspect of the feet were recorded for a 10-sec interval once during each minute of each condition’s 7-min trial. Results: The off-loading insole and specialized cleat condition yielded significantly lower (P < .01) peak pressure, contact area, and pressure–time integral values in the forefoot than the specialized cleat condition with gym shoe, which yielded significantly lower values (P < .01) than the standard gym shoe and pedal. Conclusion: Modifications to footwear may alter plantar forefoot pressures, contact area, and pressure–time integrals while cycling. The CLEAR Cleat could play a significant role in the facilitation of fitness in patients with (or at high risk for) neuropathic wounds. (J Am Podiatr Med Assoc 98(4): 261–267, 2008)


Author(s):  
K. Han Kim ◽  
Bernard J. Martin

The purpose of the present study is to investigate movements of the head spatially and temporally coordinated with hand reach movements simulating industrial assembly tasks. The motions recorded from thirty subjects performing reach movements with the right hand toward eccentric targets indicate that 1) hand movement onset lags head movement onset with a duration proportional to target eccentricity; 2) the head does not aim directly at a target, but travels only a fraction of target eccentricity and often deviates away from the target substantially; and 3) head movements are constrained by the strategy of either controlling the head position in space or controlling head rotation about the torso. These results indicate that head movements are constrained by both visual and non-visual factors. While the major function of the head is to displace the visual gaze toward the target, non-visual constraints, which include postural coordination with whole body movements, also significantly affect head movements.


2006 ◽  
Vol 120 (7) ◽  
pp. 534-536 ◽  
Author(s):  
B Ö Çakir ◽  
İ Ercan ◽  
Z A Çakir ◽  
Ş Civelek ◽  
S Turgut

Objective: To assess the association between the habitual head position during bedrest and the affected ear in benign paroxysmal positional vertigo (BPPV).Study design: Prospective trial of patients with active BPPV of the posterior semicircular canal, confirmed on physical examination.Methods: Seventy-five patients were asked to explain the head position and lying side they were accustomed to before falling asleep in bed.Results: Fifty patients (67 per cent) habitually adopted a lateral head position during bedrest. The ear affected by BPPV was found to be consistent with the head-lying side during bedrest in 43 cases (86 per cent) (29 cases for the right ear and 14 cases for the left ear).Conclusion: Habitual lateral head-positioning during bedrest can be a major factor leading to the development of BPPV in the ipsilateral ear.


2008 ◽  
Vol 17 (2-3) ◽  
pp. 119-130 ◽  
Author(s):  
Y.P. Danilov ◽  
M.E. Tyler ◽  
K.L. Skinner ◽  
R.A. Hogle ◽  
P. Bach-y-Rita

Vestibular dysfunction of either central or peripheral origin can significantly affect balance, posture, and gait. We conducted a pilot study to test the effectiveness of training with the BrainPort® balance device in subjects with a balance dysfunction due to peripheral or central vestibular loss. The BrainPort® balance device transmits information about the patient's head position via electrotactile stimulation of the tongue. Head position data is sensed by an accelerometer and displayed on the tongue as a pattern of stimulation. This pattern of stimulation moves forward, backward, and laterally on the tongue in direct response to head movements. Users of the device were trained to use this stimulation to adjust their position in order to maintain their balance. Twenty-eight subjects with peripheral or central vestibular loss were trained with the BrainPort balance device and tested using the following standardized quantitative measurements of the treatment effects: Computerized Dynamic Posturography (CDP) using the Sensory Organization Test (SOT), Dynamic Gait Index (DGI), Activities-specific Balance Confidence Scale (ABC), and Dizziness Handicap Inventory (DHI). All subjects had chronic balance problems and all but one had previously participated in vestibular rehabilitation therapy. The scores on the clinical tests upon entry into the study were compared to their scores following training with the BrainPort balance device. Our results exhibit consistent positive and statistically significant improvements in balance, posture and gait. These results exceed what could normally be achieved in three to five days of traditional balance training alone. Since this was not a controlled study, we are unable to distinguish the degree to which these improvements are attributable to training with the BrainPort balance device versus the balance exercises performed by all subjects as a part of the BrainPort training sessions. Nonetheless, after training with the BrainPort balance device, all subjects demonstrated significant improvements in performance beyond what might be expected from conventional vestibular rehabilitation therapy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sung Eun Kim ◽  
Jangyun Lee ◽  
Sae Yong Lee ◽  
Hae-Dong Lee ◽  
Jae Kun Shim ◽  
...  

AbstractThe purpose of this study was to investigate how the ball position along the mediolateral (M-L) direction of a golfer causes a chain effect in the ground reaction force, body segment and joint angles, and whole-body centre of mass during the golf swing. Twenty professional golfers were asked to complete five straight shots for each 5 different ball positions along M-L: 4.27 cm (ball diameter), 2.14 cm (ball radius), 0 cm (reference position at preferred ball position), – 2.14 cm, and – 4.27 cm, while their ground reaction force and body segment motions were captured. The dependant variables were calculated at 14 swing events from address to impact, and the differences between the ball positions were evaluated using Statistical Parametric Mapping. The left-sided ball positions at address showed a greater weight distribution on the left foot with a more open shoulder angle compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. These trends disappeared during the backswing and reappeared during the downswing. The whole-body centre of mass was also located towards the target for the left-sided ball positions throughout the golf swing compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. We have concluded that initial ball position at address can cause a series of chain effects throughout the golf swing.


2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0025
Author(s):  
Zhao Hong-Mou

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: To study the effect of different degrees of distal tibial varus and valgus deformities on the tibiotalar joint contact, and to understand the role of fibular osteotomy. Methods: Eight cadaveric lower legs were used for biomechanical study. Nine conditions were included: normal ankle joint (group A), 10° varus (group B), 5° varus (group C), 5° valgus (group D), 10° valgus (group E) with fibular preserved, and 10° varus (group F), 5° varus (group G), 5° valgus (group H), and 10° valgus (group I) after fibular osteotomy. The joint contact area, contact pressure, and peak pressure were tested; and the translation of contact force center was observed. Results: The joint contact area, contact pressure, and peak pressure had no significant difference between group A and groups B to E (P>0.05). After fibular osteotomy, the contact area decreased significantly in groups F and I when compared with group A (P<0.05); the contact pressure increased significantly in groups F, H, and I when compared with group A (P<0.05); the peak pressure increased significantly in groups F and I when compared with group A (P<0.05). There were two main anterior-lateral and anterior-medial contact centers in normal tibiotalar joint, respectively; and the force center was in anterior-lateral part, just near the center of tibiotalar joint. While the fibula was preserved, the force center transferred laterally with increased varus angles; and the force center transferred medially with increased valgus angles. However, the force center transferred oppositely to the medial part with increased varus angles, and laterally with increased valgus angles after fibular osteotomy. Conclusion: Fibular osteotomy facilitates the tibiotalar contact pressure translation, and is helpful for ankle joint realignment in suitable cases.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Eiki Mizutani ◽  
Riichiro Morita ◽  
Keiko Abe ◽  
Makoto Kodama ◽  
Shogo Kasai ◽  
...  

Abstract Background Epithelioid sarcoma most frequently occurs in the dermal or subcutaneous area of the distal extremities. To date, there have been three cases of primary pulmonary epithelioid sarcoma reported. We report a case of epithelioid sarcoma that is considered a primary lung tumor. Case presentation A 65-year-old asymptomatic Asian male patient underwent chest radiography during a routine health examination, and an abnormal mass was detected. His past medical history was unremarkable. He smoked 40 cigarettes every day and had slightly obstructive impairment on spirometry. He worked as an employee of a company and had no history of asbestos exposure. He underwent partial resection of the right lung by thoracoscopy. A histological examination of the tumor revealed a cellular nodule of epithelioid and spindle-shaped cells. Some of the tumor cells displayed rhabdoid features and reticular arrangement in a myxomatous stroma. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin (SMA), CD34, and epithelial membrane antigen (EMA); loss of the BAF47/INI1 protein in the tumor cells was also confirmed. A diagnosis of epithelioid sarcoma was established. Careful screening by whole-body positron emission tomography for another primary lesion after surgery did not detect any possible lesion. He had no cutaneous disease. Conclusion To our knowledge, this is the fourth case of a proximal-type epithelioid sarcoma considered as a primary lung tumor.


Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_1) ◽  
Author(s):  
Jyoti Bakshi ◽  
Clare Batten

Abstract Background/Aims  A 62-year-old accountant was referred to the metabolic bone clinic with a 2 year history of thoracic back pain and a persistently raised ALP. There were no associated red flags for her back pain. She had a history of a gluteal lump, thought to be benign, for which she had declined excision. She has hypertension and had a previous navicular fracture. Medications included bendroflumethiazide and Adcal D3. She had restriction in neck movements and was tender to percussion in the thoracic spine. There was no proximal weakness or focal neurology. Systems and joint exam were unremarkable. Methods  The case is discussed below. Results  Salient abnormal results on presentation were a raised ALP of 207 and corrected calcium of 2.34. PTH was elevated at 8.2 (NR:1.6-6.9), Vitamin D 79 and a low phosphate of 0.34 (NR:0.8-1.50). Alkaline phosphatase isoenzymes showed the raised level came from bone. Protein and urine electrophoresis were normal. A bone density scan was normal, and a recent thoracic MRI showed only degenerative change. An isotope bone scan was requested and was reported to show increased activity in the nasal bone, maxilla and both orbits, raising the possibility of Paget’s disease. However, when reviewed in the Radiology meeting with a skull x-ray, the appearances were not felt to be in keeping with Paget’s. Despite physiotherapy, hydrotherapy, acupuncture and neuropathic medication the patient’s back pain continued. Her phosphate remained low and her calculated tubular reabsorption of phosphate from a 24h urine collection (TmP/GFR) was low at 0.42mmol/l (NR 0.80-1.35). She was started on phosphate replacement and calcitriol, and Adcal D3 was continued. The Fibroblast Growth Factor (FGF) 23 levels were sent and came back significantly elevated at 1380 (NR &lt; 100). A 68Ga DOTA-TATE scan (whole body PET/CT scan), confirmed the right gluteal lump as the source of the FGF 23. The patient went on to have an excision biopsy and histology confirmed a mesenchymal tumour of the right buttock. Her phosphate replacement was gradually weaned, but on reducing the dose phosphate levels dropped and her symptoms returned. The repeat TmP/GFR was again low at 0.61, and FGF 23 levels were still raised at 204. A repeat 68Ga DOTA-TATE scan, 4 years after the first one, showed recurrence of the right gluteal lesion and a possible small lesion in the left gluteal muscle. She has been sent for further excision. Conclusion  Tumour induced osteomalacia (TIO) is a rare condition and should be considered in cases of hypophosphataemia. Classical symptoms are proximal weakness and muscle and bone pain. They are typically associated with small benign tumours (most commonly mesenchymal tumours) which may be difficult to find. Excision is curative but if small amounts of tumour remain, relapses may occur. Disclosure  J. Bakshi: None. C. Batten: None.


2009 ◽  
Vol 24 (5) ◽  
pp. 275-281 ◽  
Author(s):  
Teresa Rodriguez-Cano ◽  
Luis Beato-Fernandez ◽  
Inmaculada Garcia-Vilches ◽  
Ana Garcia-Vicente ◽  
Victor Poblete-Garcia ◽  
...  

AbstractObjectiveThe aim of the present study is to see if the changes in the regional cerebral blood flow (rCBF) experienced by restrictive anorexia nervosa (AR) and bulimia nervosa (BN) patients, following the exposure to their own body image, persist at follow-up.MethodsThree single photon emission computed tomography (SPECT) were performed on nine patients with a DSM-IV diagnosis of AR, 13 with BP, and 12 controls: at rest, following a neutral stimulus, and after exposure to their previously filmed whole body image. Body dissatisfaction was measured by means of the Body Dissatisfaction Questionnaire (BSQ). One year later the same assessment was repeated.ResultsFollowing the exposure to their own body image, BN showed an increase in body dissatisfaction, which was associated with the increase in the rCBF of the Right Temporal Area. Those changes persisted at follow-up.DiscussionMore specific long term therapies are needed for the treatment of the averse response showed by ED patients to their own body image exposure that is associated with the hyperactivation of the right temporal area when they are confronted with their whole body image.


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