Suprascapular neuropathy in volleyball players

BACKGROUND

Suprascapular nerve entrapment with isolated paralysis of the infraspinatus muscle is uncommon. However, this pathology has been reported in volleyball players. Despite a lack of scientific evidence, excessive strain on the nerve is often cited as a possible cause of this syndrome. Previous research has shown a close association between shoulder range of motion and strain on the suprascapular nerve. No clinical studies have so far been designed to examine the association between excessive shoulder mobility and the presence of this pathology.

AIM

To study the possible association between the range of motion of the shoulder joint and the presence of suprascapular neuropathy by clinically examining the Belgian male volleyball team with respect to several parameters.

METHODS

An electromyographic investigation, a clinical shoulder examination, shoulder range of motion measurements, and an isokinetic concentric peak torque shoulder internal/external rotation strength test were performed in 16 professional players.

RESULTS

The electrodiagnostic study showed a severe suprascapular neuropathy in four players which affected only the infraspinatus muscle. In each of these four players, suprascapular nerve entrapment was present on the dominant side. Except for the hypotrophy of the infraspinatus muscle, no significant differences between the affected and non-affected players were observed on clinical examination. Significant differences between the affected and non-affected players were found for range of motion measurements of external rotation, horizontal flexion and forward flexion, and for flexion of the shoulder girdle (protraction); all were found to be higher in the affected players than the non-affected players.

CONCLUSIONS

This study suggests an association between increased range of motion of the shoulder joint and the presence of isolated paralysis of the infraspinatus muscle in volleyball players. However, the small number of patients in this study prevents definite conclusions from being drawn.

Muscular rigidity and delineation of a dopamine-specific neostriatal subregion: tonic EMG activity in rats

In order to investigate the role of neostriatal dopamine receptors in muscular rigidity we have studied catalepsy and spontaneous muscle tone in rats receiving haloperidol injections into various parts of the neostriatum. It was found that low doses of haloperidol (250-750 ng/0.5 microliter) induced a tonic activity in the EMG of the gastrocnemius-soleus muscle when injected into the most rostral part of the neostriatum (A 8620-9650). This tonic EMG activity was found to be both dose-dependent and dopamine-specific: the haloperidol effect of 500 ng could be inhibited by 500 ng apomorphine. No muscular rigidity could be observed when haloperidol (500 ng/0.5 microliter) was injected further caudally into the neostriatum or into the medial part of the nucleus accumbens. With regard to the haloperidol-induced catalepsy as measured by means of the bar test, a similar distribution of effective and ineffective injection sites was observed; however, higher doses of haloperidol (1.5-2.5 micrograms/0.5 microliter) were required. Thus catalepsy and muscular rigidity were found to be closely related phenomena within the neostriatum. Finally, it is discussed how information relevant to tonic EMG activity is transmitted from the substantia nigra pars compacta to the superior colliculus and the ventromedial thalamus via the neostriatum and the substrate nigra pars reticulata.

Differential susceptibility to periodontitis in genetically selected Wistar rat lines that differ in their behavioral and endocrinological response to stressors

This study tests the model presented previously by Breivik et al. (1996), in which the extent of periodontitis, an inflammatory disease, is predicted from the reactivity of the HPA-axis. Briefly, the model implies that elevated plasma levels of corticosterone modulate the immune system by shifting the T-helper balance toward a more Th2 response, which, alternately, increases the sensitivity to periodontitis. To test this model, two genetically distinct types of rats that differ both behaviorally and endocrinologically in their response to stress (high corticosterone responding APO-SUS rats and low corticosterone responding APO-UNSUS rats) were compared. Periodontitis was experimentally induced through the placement of a ligature and measured as the extent of tissue (fiber and bone) loss, both histologically and radiographically. The results show that, as expected, APO-SUS animals are more sensitive to periodontitis, i.e., show more fiber and bone loss, than APO-UNSUS animals. These data are in agreement with findings in Fischer and Lewis rats, as well as with corticosterone treated and adrenalectomized animals and suggest that genetic factors underlying the variation in the reactivity of the HPA-axis (and, accordingly, their behavioral response to stress) play an important a role in the development of inflammatory diseases.

The interrelationship between superior colliculus and substantia nigra pars reticulata in programming movements of cats

Recent electrophysiological and behavioural studies have suggested that the deeper layers of the superior colliculus (dl-SC) are involved in the execution of targeting movements which are elicited but not continuously guided by external stimuli. In the first part of the present study the role of the GABAergic transmission in the dl-SC in the execution of these targeting movements was investigated. Therefore cats, trained to walk from one side of a narrow bar towards the target at the other side of the bar under stroboscopic illumination (2 flashes/s), were injected bilaterally in the dl-SC with picrotoxin (100 ng/0.5 microliter) or muscimol (75 ng/1 microliter). In the second part of this study the role of the GABAergic activity in the substantia nigra pars reticulata (SNR), projecting to the dl-SC through the GABAergic nigrotectal pathway, in the execution of the above-mentioned targeting movements was investigated. Therefore cats, trained to walk from one side of a narrow bar towards the target at the other side of the bar, either under full light or under stroboscopic illumination (2 flashes/s), were bilaterally injected in the SNR with picrotoxin (500 ng/0.5 microliter) or muscimol (200 ng/1 microliter). Under stroboscopic illumination (2 flashes/s) solvent-treated cats either continuously grasped the bar and/or continuously touched the bar with their whiskers, i.e. they executed movements which were continuously guided by external stimuli, while walking towards the target at the other side of the bar.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of peripartal feeding strategy on colostrum yield and composition in sows

Research showed a positive association between back fat (BF) change the week before farrowing and colostrum yield (CY). This study tested the causality of this association, hence to optimize CY by altering the sows' peripartal feeding strategy. Sows were randomly divided into 2 treatment groups at d 108 of gestation. The first group (L, n = 28) received 1.5 kg feed·d(-1), the second group (H, n = 22) received 3 times 1.5 kg feed·d(-1) until farrowing. Daily feed intake and CY were measured. Colostrum was analyzed for nutrient composition, AA and fatty acids, IgG and IgA. Sow serum was obtained at d 108 of gestation and d 1 of lactation after overnight fasting and analyzed for NEFA, (iso)butyrylcarnitine (C4), creatinine, urea, 3-OH-butyrylcarnitine (3-OH-C4), IgG, and IgA. Based on BF at d 108, sows were divided into body condition (BC) groups: skinny (<17 mm, n = 15), moderate (17 to 23 mm, n = 21), fat (>23 mm, n = 14). We performed ANOVA with treatment and BC as fixed factors and Scheffé post-hoc test. The week before farrowing, the L group had the lowest daily feed intake (DFI; 1.5 kg), and within the H group, fat sows (3.8 kg) had a lower DFI than skinny sows (4.3 kg; p = 0.006). The H group tended to have a greater total CY (P = 0.074) and had a greater CY/kg liveborn piglet (P = 0.018) than the L group. Compared with sows in moderate BC, fat sows had a lower total CY (P = 0.044) and a lower CY/kg liveborn piglet (P = 0.005). The H group had a greater concentration of lactose (p = 0.009) and n-3 PUFA (p < 0.001) but a lower concentration of protein (p = 0.040) in colostrum than the L group. The concentration of IgG and IgA did not differ between treatment and BC groups. Serum parameters at d 108 were similar between the treatment groups and BC groups. At d 1, the H group mobilized less body fat (NEFA: p = 0.002) and protein (creatinine: p < 0.001, C4: p = 0.016) reserves but had a greater ratio urea:NEFA (p < 0.001) and less ketone bodies (3-OH-C4: p < 0.001) compared with the L group. This indicates a more balanced entry of metabolites in the citric acid cycle and thus a better support of the maternal peripartal metabolism in the H group. Serum parameters did not differ between BC groups. Both CY and composition can be influenced by the peripartal feeding strategy and BC. The highest CY and most beneficial colostrum composition were obtained when sows entered the farrowing unit in a moderate BC and were provided a high peripartal feeding strategy.

Ad libitum feeding during the peripartal period affects body condition, reproduction results and metabolism of sows

To overcome negative energy balance during the peripartal period of sows, an ad libitum feeding strategy (ADLIB) as alternative for commonly used restricted feeding (STANDARD, on average 3kg feed/day) was evaluated. Plasma metabolites and thyroid hormones, change of back fat thickness (BF), reproductive traits, and piglet performance were monitored. Voluntary feed intake of ADLIB sows declined at farrowing but was still more than twice the amount of what was offered to STANDARD sows. Consequently, ADLIB sows lost less BF than STANDARD sows (P=0.041). Additionally, BF change was affected by body condition. LEAN sows (BF<18mm on d 105 of gestation) lost less BF than MODERATE sows (18mm≤BF≤22mm) which lost less BF than FAT sows (BF>22mm) (P<0.001). Except for a decreased percentage of stillborn piglets for MODERATE sows (P=0.044), reproduction results were not affected. Piglet weaning weight of ADLIB-FAT and STANDARD-MODERATE sows was reduced in comparison with that of ADLIB-LEAN sows (P=0.005). Regardless of body condition, all metabolites and thyroid hormones measured showed a time dependent profile (P<0.001). On d 112 of gestation increased concentrations of creatinine (P=0.004), non-esterified fatty acids (P=0.039), and serum crosslaps (P=0.016) for STANDARD sows were observed. Triglycerides were increased for FAT sows (P<0.001), and decreased faster over time for ADLIB (P=0.013) and for FAT (P=0.012). Although ad libitum feeding during the peripartal period only resulted in less mobilization of muscle, fat, and bone reserves on d 112 of gestation, results of BF change and piglet weaning weight indicated that ad libitum feeding is beneficial for sow performance provided that BF is below 22mm.

The importance of the striato-nigro-collicular pathway in the expression of haloperidol-induced tonic electromyographic activity

Experiments were carried out to investigate the participation of the striatonigral and nigrocollicular GABAergic pathways in the expression of haloperidol-induced tonic electromyographic (EMG) activity of the gastrocnemius-soleus muscle in awake rats. It was shown that bilateral injections of haloperidol (500 ng/0.5 microliter) into the rostral part of the neostriatum induced a tonic EMG activity which could be significantly reduced by a second bilateral injection of muscimol (25 ng/0.5 microliter) into the substantia nigra pars reticulata (SNR) or of bicuculline (50 ng/0.5 microliter) into the intermediate or deep layers of the colliculus superior (CS). These results suggest that the striatonigral and nigrocollicular GABAergic pathways play a critical role in the transmission of haloperidol-induced tonic EMG activity.

Does the application of kinesiotape change scapular kinematics in healthy female handball players?

Elastic taping is widely used in sports medicine for correcting functional alignment and muscle recruitment. However, evidence regarding its influence on scapular dynamic positioning is scarce. This study aimed to investigate the effect of a specific kinesiotaping method on scapular kinematics in female elite handball players without shoulder complaints. 25 athletes (18.0±1.5 years) active in the highest national division were recruited. All subjects received an elastic adhesive tape (K-active tape©) with the purpose to correct scapular position. 3-dimensional scapular motion measurements were performed (Fastrak®) during humeral elevation in the sagittal, frontal and scapular plane. The results showed that taping has a moderate to large effect (Cohen's d>0.7) towards scapular posterior tilting, in all 3 planes of humeral movement and for all angles of elevation (mean posteriorizing effect of 4.23 °, 3.23 ° and 4.33 ° respectively for elevation in the sagittal, frontal and scapular plane, p<0.001). In addition, taping also moderately increased the scapular upward rotation at 30 °, 60 ° and 90 ° of humeral abduction (mean increase of 2.90 °, Cohen's d>0.7). Together these results suggest that kinesiotape application causes positive changes in scapular motion. This could support its use in sports medicine for preventing shoulder problems in overhead athletes.

Which factors predict outcome in the treatment program of anterior knee pain?

The goal of this prospective study was to determine the outcome-predictive role of various parameters in the nonoperative treatment of chronic anterior knee pain patients. Thirty patients followed a five-week treatment program, which consisted out of only closed kinetic chain exercises. Prior to this treatment all subjects were evaluated on muscular characteristics, subjective symptoms, weight, sex, duration of symptoms and functional performance. A multiple stepwise regression analysis revealed that the reflex response time of m. vastus medialis obliquus (VMO) (P=0.041; 0.026), and the duration of symptoms (P=0.019; 0.045) were the only two parameters which were significantly associated with the outcome (evaluated by the Kujala score) at five weeks, and at three months. The shorter the duration of symptoms, or the faster the reflex response time of VMO prior to the treatment, the better the outcome after a closed kinetic chain exercise program. The statistical significance of these parameters in this study may be seen as an indication of the importance of these variables as predictors of the outcome of a closed kinetic chain strengthening program. Using this information, it seems clinically important to begin the treatment program before the anterior knee pain becomes more chronic and treatment results become less good.

The role of the colliculus superior in the expression of muscular rigidity

Muscular rigidity, recorded as tonic activity in the electromyogram of the gastrocnemius-soleus muscle in the rat was produced by bilateral injections of muscimol (37.5-75 ng) into the intermediate or deep layers of the colliculus superior. This effect of muscimol was not only dose-dependent but also gamma-aminobutyric acid (GABA)-specific since it could be prevented by coadministration of the GABA antagonist bicuculline methiodide. Injections of muscimol into either the superficial layers of the colliculus superior or the underlying reticular formation were without effect in this respect. These results indicate that the region containing the terminals of the nigrocollicular pathway is involved in the expression of muscular rigidity (recorded as a tonic EMG activity). Muscimol injections into the colliculus superior did not lead to catalepsy thus providing additional evidence for the notion that muscular rigidity and catalepsy are two separate phenomena which are in part mediated by different neuronal pathways.

Effects of hippocampal lesioning on experimental periodontitis in Wistar rats

The hippocampus, which is a brain structure involved in learning and memory processes, plays a key role in the feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis and autonomic sympathetic nervous system, and the subsequent secretion of immuno-modulatory hormones in response to pathogenic microorganisms. Dysregulation of these brain-neuroendocrine-immune regulatory networks, which act in concert to maintain homeostasis, is found to be of critical importance to the host defence against pathogens, as well as susceptibility to diseases, including periodontal disease. The present study was designed to determine the effects of hippocampal lesioning on the progression of periodontitis. Experimental ligature-induced periodontitis was induced in 16 Wistar rats, which were bilaterally lesioned in their hippocampal region with an aspiration technique that is well documented to impair learning and memory, as well as in 15 sham-operated control rats. The disease progression was evaluated radiographically and histometrically. The results revealed that the hippocampal lesioned rats developed significantly more destruction of the periodontium than did the sham-operated controls. This finding supports recent studies that indicate that inappropriate brain-neuroendocrine regulation of inflammatory responses to infectious agents may play an important role in disease susceptibility and progression.

Effect of intracaudate haloperidol and apomorphine on switching motor patterns upon current behaviour of cats

Previous studies using various experimental set-ups, have shown that the dopaminergic activity in the caudate nucleus (CN) is involved in the organism's ability to switch from one motor or behavioural program to another without the help of external stimuli (switching arbitrarily). The main purpose of the present study was to investigate how arbitrarily switching motor patterns manifests itself in an 'open field situation'. Therefore, the effects of CN application of haloperidol (12.5 micrograms/5 microliter) and apomorphine (0.6 micrograms/5 microliter) were analyzed on the ability to switch from one motor program to any other program in cats habituated to an observation cage. Application of haloperidol decreased switching. In addition the number of distinct motor patterns declined after injecting haloperidol into the CN. The haloperidol-induced effect, however, was not selectively restricted to any particular motor pattern. Switching from one motor pattern to another increased after CN injection of apomorphine. Moreover, the number of distinct motor patterns increased after CN injection of apomorphine. However, the effect of CN application of apomorphine was not selectively restricted to any particular motor pattern. Since previous studies have demonstrated that various expressions of dopaminergic CN activity are funnelled through the deeper layers of the superior colliculus (dl-SC), it was hypothesized that switching induced by CN application of apomorphine may also be channelled through the dl-SC. Therefore the effect of dl-SC-injected muscimol (75 ng/1 microliter) was analyzed on the ability to switch motor programs in cats pretreated with apomorphine. Injection of muscimol into the dl-SC reduced both the number of distinct motor patterns and the number of switchings in cats pretreated with apomorphine.

Peripartum changes in orexigenic and anorexigenic hormones in relation to back fat thickness and feeding strategy of sows

Highly prolific sows often experience peripartum hypophagia, resulting in decreased production rate. Leptin, ghrelin, and resistin are known as feed intake-regulating hormones in many species, but it is yet unknown how feeding strategy and body condition will affect these hormones around parturition in sows. In the present study, a total of 63 sows, parity 2 to 7 were divided over 2 treatment groups which were fed either restricted (RESTRICT) or ad libitum (ADLIB) during the peripartum period (day 106 of gestation until day 7 of lactation). Within each treatment group, sows were assigned to 1 of 3 body condition groups based on back fat thickness at day 106 of gestation: <18 mm (LEAN), between 18 and 22 mm (MODERATE), and >22 mm (FAT). Postprandial blood samples were taken on days 107, 109, and 112 of gestation and on days 1, 3, and 5 of lactation. With RIA, leptin, ghrelin, and resistin of each sample were analyzed. For both leptin and resistin, the hormonal profile gradually increased throughout the peripartum period (P < 0.001), whereas ghrelin peaked on day 109 of gestation compared with day 107 of gestation and day 1 of lactation. Other time points were intermediate between those two (P < 0.001). The peripartum profile of leptin was significantly higher for FAT sows than for the 2 other condition groups. No effect of body condition on ghrelin and resistin concentrations was observed. None of the 3 measured hormones were affected by feeding strategy. In conclusion, during the peripartum period feed intake of sows did not affect leptin, ghrelin, or resistin profiles. Leptin was the only hormone investigated that reflected body condition. Although body condition and late gestation feed intake have been previously described as risk factors for peripartum hypophagia, they did not induce hypophagia in any of the sows or affect the profile of the observed feed intake-regulating hormones during the peripartum period.