Stapedius muscle fibre characterization in the noise exposed and auditory deprived rat.

In skeletal muscle, interventions that unload the muscle cause slow-to-fast myosin heavy chain (MHC) conversions, whereas fast-to-slow conversions are seen when the muscles are engaged in resistance training and endurance exercise. The stapedius muscle (SM) is reported to prevent cochlear damage by noise. This theory may be supported by showing comparable changes of muscle fibre composition when ears are exposed to longstanding noise (SM training). Comparable changes after sound deprivation (SM unloading) would suggest that the SM needs a certain degree of daily activity evoked by environmental sound to sustain its normal composition. We investigated the difference in myosin composition of SM fibres from rats exposed to noise, from auditory deprived rats and from rats exposed to low level ambient noise (control group). Consecutive complete SM cross-sections were processed by enzymehistochemistry to determine acid/alkali lability of myofibrillar adenosine triphosphatase (mATPase) and by immunohistochemistry using MHC antibodies. Fibres were assigned to mATPase type I, IIA, IIX or 'Miscellaneous' categories. Per mATPase category, the fibres were attributed to groups with specific MHC isoform compositions. Auditory deprivation lasting nine weeks was accomplished by closure of the external meatus at the age of three weeks. A slow-to-fast shift was seen in these rats when compared to the control group. The noise exposed group was exposed to 65-90dB sound pressure level during a period lasting nine weeks from the age of three weeks onwards. A shift from an overwhelming presence of type mATPase IIX, as seen in the control group, to type mATPase IIA occurred in the noise exposed group. Also, more MHC IIA/IIX hybrid fibres were found in the mATPase IIX category. An adaptive response to the acoustic environment in the characteristics of the fibres of the SM, comparable to the response in skeletal muscles on unloading and training activity, can be ascertained. This supports the theory that the SM plays an active role in modulating external acoustic energy on entry to the cochlea. Our results are also in favour of another postulated function of the SM, the unmasking of high-frequency signals in low-frequency background noise.

Manual therapy, physical therapy, or continued care by the general practitioner for patients with neck pain: long-term results from a pragmatic randomized clinical trial.

OBJECTIVES: The authors' goals were to compare the effectiveness of manual therapy (MT; mainly spinal mobilization), physical therapy (PT; mainly exercise therapy), and continued care by the general practitioner (GP; analgesics, counseling and education) over a period of 1 year. METHODS: One hundred eighty-three patients suffering for at least 2 weeks from nonspecific neck pain were randomized to receive a 6-week treatment strategy of MT once a week, PT twice a week, or GP care once every 2 weeks. The primary outcome measures were perceived recovery, severity of physical dysfunctioning, pain intensity, and functional disability. RESULTS: The differences between groups considered over 1 year were statistically significant (repeated measurements analyses P<0.001 to P=0.02) for all outcomes but borderline for the Neck Disability Index (P=0.06). Higher improvement scores were observed for MT for all outcomes, followed by PT and GP care. The success rate, based on perceived recovery after 13 weeks, was 72% for MT, which was significantly higher than the success rate for continued GP care (42%, P=0.001) but not significantly higher compared with PT treatment (59%, P=0.16). The difference between PT and GP approached statistical significance (P=0.06). After 1 year the success rates were 75%, 63%, and 56%, respectively, and no longer significantly different. CONCLUSIONS: Short-term results (at 7 weeks) have shown that MT speeded recovery compared with GP care and, to a lesser extent, also compared with PT. In the long-term, GP treatment and PT caught up with MT, and differences between the three treatment groups decreased and lost statistical significance at the 13-week and 52-week follow-up.

The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients

Plantar intrinsic foot muscles provide structure to the foot during walking and thus regulate mechanical foot sole stresses. When paralyzed, for instance in leprosy patients with neuropathy of the distal part of the tibial nerve, there is a high prevalence of plantar ulceration and deformities, especially when muscle weakness goes together with loss of foot sole sensibility. These patients should get immediate care involving education, special footwear and reconstructive surgery before further foot impairment and deformity becomes manifest. Thus far, in leprosy patients little attention is paid to screening of plantar intrinsic muscles activity. This can be done with a new simple and non-invasive method, the Paper Grip Test (PGT). There are two variants for detecting intrinsic muscle weakness of the foot, PGT1 for the great toe and PGT2 for the combined lesser toes. In this study, 517 leprosy patients and 170 healthy volunteers were investigated with the PGT. Sensibility of the foot sole was tested by means of a 10 gram monofilament. Specificity to the PGT1 is found to be about 95.3% which is considered good for physical diagnostic tests. PGT2 is less specific than PGT1. Individual muscle power and understanding of the patient seems to influence the outcome of the test to a certain extent. Sensitivity can only be calculated when the diagnosis is confirmed by electromyography. Especially patients with anesthetic feet, females, older patients and patients with PN-, BB- or LL-types of leprosy appeared to have a higher prevalence of intrinsic foot muscle weakness. All results were analyzed by means of the bivariate Pearson correlation-analysis and proved to be statistically significant (p = < 0.05). It is concluded that the PGT1, more than the PGT2, is a useful screening test on the function of plantar intrinsic foot muscles in leprosy patients in hospitals and during fieldwork in developing countries.