Inter-joint coordination and the flexion-relaxation phenomenon among adults with low back pain during bending.

BACKGROUND: Altered inter-joint coordination and reduced flexion-relaxation at end-range trunk flexion are common in people with low back pain. Inconsistencies in these behaviors, however, make assessment and treatment challenging for this population. RESEARCH QUESTION: The study objective was to investigate patterns of regional lumbo-pelvic coordination and flexion-relaxation in adults with and without low back pain, during a bending task. METHODS: Adults with low back pain (n = 16) and a healthy group (n = 21) performed three trials of a bending task. Motion capture and surface electromyography systems measured joint kinematics (hip, lower and upper lumbar spine) and muscle activity (erector spinae longissimus, iliocostalis, and multifidus). Continuous relative phase analysis determined inter-joint coordination of the hip/lower lumbar and lower lumbar/upper lumbar joint pairs, during flexion and extension periods. Flexion-relaxation ratios using normalized surface electromyography data determined the extent of flexion-relaxation for each muscle, during each period. For inter-joint coordination, two-way repeated measure mixed ANOVAs calculated the effects of group (healthy/low back pain), period, and their interactions. Separate hierarchical linear models were constructed and tested relationships between flexion-relaxation ratios and our independent variables, group and muscle, while controlling for patient characteristics. RESULTS: The low back pain group had more out-of-phase coordination of the hip/lower lumbar joint pair compared to the healthy group (mean difference = 24.7°; 95 % confidence interval = 3.93-45.4), independent of movement period. No significant between group differences in lower lumbar/upper lumbar coordination were observed. The low back pain group demonstrated reduced flexion-relaxation of all muscles during full flexion (21.7 % reduction on average), with multifidus showing the least relaxation. SIGNIFICANCE: Regional differences in the lumbar spine and the possibility of subgroups with distinct movement pattern should be considered when analyzing coordination in people with low back pain. Multifidus showed the largest changes in flexion-relaxation and should be included when measuring this construct.

The effects of triclosan on puberty and thyroid hormones in male Wistar rats.

Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a potent antibacterial and antifungal compound that is widely used in personal care products, plastics, and fabrics. Recently triclosan has been shown to alter endocrine function in a variety of species. The purpose of this study was to determine effects of triclosan on pubertal development and thyroid hormone concentrations in the male rat. Weanling rats were exposed to 0, 3, 30, 100, 200, or 300 mg/kg of triclosan by oral gavage from postnatal day (PND) 23 to 53. Preputial separation (PPS) was examined beginning on PND 33. Rats were killed on PND 53, organ weights were recorded and serum was collected for subsequent analysis. Triclosan did not affect growth or the onset of PPS. Serum testosterone was significantly decreased at 200 mg/kg, however no effects were observed on androgen-dependent reproductive tissue weights. Triclosan significantly decreased total serum thyroxine (T4) in a dose-dependent manner at 30 mg/kg and higher (no observed effect level of 3 mg/kg). Triiodothyronine (T3) was significantly decreased only at 200 mg/kg, but thyroid stimulating hormone was not statistically different at any dose. Liver weights were significantly increased at 100 mg/kg triclosan and above suggesting that the induction of hepatic enzymes may have contributed to the altered T4 and T3 concentrations, but it does not appear to correlate with the T4 dose-response. This study demonstrates that triclosan exposure does not alter androgen-dependent tissue weights or onset of PPS; however, triclosan exposure significantly impacts thyroid hormone concentrations in the male juvenile rat.

Comparison of localized injections of spinosad and selected insecticides for the control of Cryptotermes brevis (Isoptera: Kalotermitidae) in naturally infested structural mesocosms.

We investigated the efficacy of various chemical injections against Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae) in hardwood shipping pallets. We had three principle interests: efficacy in whole structures, relative efficacy of the active ingredients, and whether acoustic evidence augmented treatment site selection. Infested pallets were delineated into boards with four monitoring sites each. Six chemical treatments were compared: chlorpyrifos aerosol, aqueous disodium octaborate tetrahydrate (DOT), resmethrin aerosol, distilled water (control), and two treatments of spinosad SC (one treatment applied based upon visual and the other treatment upon acoustic [AE] evidence). Individual boards were split apart; efficacy was determined by percentage mortality and pre- and posttreatment AE counts. Injections were constrained to a single point per board with the greatest level of termite activity. In whole pallets, mean percentage mortality ranged from 53.3 to 58.7% for the visual and AE spinosad treatments, respectively, whereas water averaged 6.8%. Remaining treatment mortalities were 33.2, 30.4, and 18.1% for chlorpyrifos, DOT, and resmethrin, respectively. Analysis of whole-pallet data indicated that none of the insecticides produced commercially acceptable mortality; localized injections of insecticides were not comparable with whole-structure treatments. We delineated independent groups of board sections (sectional aggregates; SA) that were connected by galleries. When treated SA were analyzed, spinosad and DOT treatments were significantly different from controls, whereas remaining treatments were not different from controls or spinosad and DOT. AE readings and visual termite evidence were compared with presence or absence of termites in SA, and it was determined that both AE and visual evidence were effective predictors of termite presence.

Identification of termite species by the hydrocarbons in their feces.

Blends of abundant cuticular hydrocarbons are species-specific for termites (Isoptera) and can be used to identify a given taxon without the diagnostic castes, soldiers or adults. We demonstrate that hydrocarbon extracts of termite fecal pellets from damaged wood can also be characterized and used to identify termites responsible for damage, even though termites are no longer present or easily recovered. In structures infested by drywood termites, it is common to find fecal pellets, but difficult to extract termites from the finished wood in service. Nine species belonging to two families (Kalotermitidae and Termopsidae) were examined to compare the hydrocarbon composition of termites and their fecal pellets. Diversity was extensive: at least one half of the amount of the hydrocarbons from Neotermes connexus, Incisitermes immigrans, Cryptotermes brevis, Cryptotermes cynocephalus, Procryptotermes corniceps, and Zootermopsis nevadensis nuttingi was olefins. Incisitermes minor and Pterotermes occidentis incorporated only small amounts of olefins in cuticular hydrocarbons; Marginitermes hubbardi had no detectable olefins. Hydrocarbons extracted from fecal pellets were qualitatively and quantitatively similar to cuticular extracts and can be used to determine the termite species responsible without the termites present.

Creating roles for social work in changing health care organizations: organizational development perspective.

Social work has historically been influenced by and influential in periods of social change. The current health care environment poses challenges to the profession whose function is to maximize adaptation. In addition to helping patients and families adapt to a rapidly changing health delivery system, social workers can develop roles that affect the direction and impact of organizational change, substantively if not fundamentally. This includes assisting staff to work professionally and maintain client-focus during organizational stress and chaos. This article develops one example of how social work expanded its role during a time of transition through staff education of another discipline at Mount Sinai Medical Center in New York City, USA. The authors conceptualize the need for such practice, describe and analyze the program, and extrapolate practice principles for expanding social work roles in a changing work organization.

Effect of lumbar orthotics on trunk muscle strength.

Weakening of the trunk muscles is thought to be one disadvantage of prolonged lumbar orthotic use. This study examines weakness of the trunk flexor and extensor muscles in patients who are wearing lumbar orthotics for extended periods. Strength of the trunk flexor and trunk extensor muscles was tested in 24 individuals, using the Kinetic computer. Both concentric and eccentric forces were recorded. Four groups of patients were studied. Group 1 (n = 6) consisted of patients with low back pain who had used a lumbar orthotic for a prolonged period of time. Group 2 (n = 6) consisted of hospital employees with no history of low back pain, who wore lumbar orthotics prophylactically, for back protection. Group 1C (n = 6) consisted of healthy controls, with no history of either back pain or lumbar orthotic use, who were individually age- and gender-matched to each patient in Group 1. Group 2C (n = 6) consisted of healthy controls matched in the same fashion to each patient in Group 2. After consultation with a statistician, statistical analysis was performed using the Wilcoxon's test. Nonparametric statistics were chosen because of the lack of evidence of a normal distribution of the parameters being studied. This analysis revealed significant weakness in concentric flexion (P = 0.0464), concentric extension (P = 0.0277), and eccentric extension (P = 0.0464) in Group 1 compared with matched controls in Group 1C. The only significant weakness compared with controls in Group 2 was in eccentric flexion (P = 0.0277). Trends were toward weakness in the orthotic users for the other motions studied, with a P value of less than 0.1 for eccentric extension. Prolonged use of lumbar orthotics may be associated with trunk muscle weakness in the population studied. Prescribers should continue to limit duration of use when possible and to consider strengthening exercises when prolonged use is anticipated.

Field trials with methoprene, temephos, and Bacillus thuringiensis serovar israelensis for the control of larval Culiseta melanura.

In 1992, Altosid (methoprene) pellets, Abate (temephos) 5 CG, and Bactimos (Bacillus thuringiensis serovar israelensis) granules were applied aerially to small field plots within a Culiseta breeding swamp. Aspects measured included the deposition and diffusion of larvicides into larval crypts and effects on larval Culiseta melanura and nontarget aquatic organisms. Formulations were deposited at approximately 50% of application rates. The presence of methoprene in 8 crypt water samples indicated that this larvicide was able to diffuse into Cs. melanura larval crypts. Methoprene was selected for evaluation in a large-scale field trial. In the spring of 1993, methoprene pellets applied to 25% of the study area were an effective larvicide against Cs. melanura. The inhibitory effect on pupae exceeded 81% over a 5-wk posttreatment period.

Use of a modified chemical transfer pump for sampling Culiseta melanura larvae.

The cryptic nature of Culiseta melanura larval habitats has limited the use of the conventional one-pint dipper for enumerating the larval density of this species. A modified chemical transfer pump was used in a survey of a known breeding swamp. Field trials assessed the practicality and potential biases towards instars in open vs. closed crypts. From 148 samples taken at 37 sites, 631 Cs. melanura larvae were collected. Closed crypts accounted for 21% of the positive samples. The pump had utility in the field but a relative scarcity of 4th-instar larvae in the samples may indicate a source of bias toward younger instars.