Introduction & Objectives: In recent studies, the negative effects of smoking on different parts of body have been cleared. Nevertheless other negative effects of smoking are being investigated. One of those effects is central and peripheral nervous system problem. The aim of this investigation was comparison of Hoffmann (H) reflex latency of tibial nerve in male smokers and non smokers between 20-40 y/o. In addition, correlation between height and Hreflex latency was investigated.Materials & Methods: In this case - control study, samples included 65 males (32 smokers and 33 non-smokers) 20-40y/o. After assuring of desired conditions H-REFLEX latency was measured. In smokers, H-REFLEX test was done at least one hour after cigarette consumption. Before measuring H-REFLEX latency distal lower extremity skin temperature was measured and the study was done at 33 °C skin temperature.Results: The average of H-REFLEX latency in smokers was 29.9±1.5 ms and the average of Hreflex latency in non-smokers was 29.25±1.3 ms. The results showed that there is no significant difference between H-REFLEX latency in male smokers and non-smokers (p>0.05).Conclusion: Therefore, cigarette consumption does not have any effect on H-REFLEX latency in males between 20-40y/o. Also, correlation test indicate that there is significant relationship between height and H-REFLEX latency.

Lumbosacral radiculopathy is a challenging diagnosis, and Electrodiagnostic study (EDX) is a good complementary test for Magnetic Resonance Imaging (MRI). Physical examination, MRI and electrodiagnosis have different diagnostic values in this regard. MRI can provide anatomical evidence and is useful in choosing a treatment process, but it could also have false positive results. In this study, we assessed the correlation of clinical and electrodiagnostic findings in patients with positive MRI findings for S1 radiculopathy. EDX was performed for 87 patients referred with clinical and MRI diagnosis of S1 radiculopathy. The consistency between EDX results, MRI, and clinical findings were evaluated by Pearson chi 2 and odds ratio. Fifty-eight percent of patients had disc protrusion, and 42% had extrusion. Physical examination revealed absent Achilles reflex in 83% and decreased S1 dermatome sensation in 65%. In this study, EDX sensitivity was about 92%. The highest consistency among EDX parameters and physical examination findings was between absent Hreflex and decreased Achilles reflex (OR=6. 20, P=0. 014), but there was no significant consistency between Hreflex and neither muscular weakness nor SLR test result (P>0. 05). There was also no relationship between type of disc herniation in MRI and H reflex. There was correlation between H-REFLEX abnormalities and absent ankle reflex in patients with unilateral L5-S1 disc herniation in MRI. Results of this study showed that in patients with positive MRI for L5-S1 disc protrusion and S1 nerve root compression, it is still beneficial to perform EDX for selected patients.

Introduction: Mechanoreceptors of foot sole likely contribute in the reflex regulations. Stimulation of these receptors in the lateral aspect of the foot is corresponded to the lateral plantar division of the tibial nerve. Therefore, it was hypothesized that repetitive low threshold afferents stimulation would have an inhibitory effect on the soleus H-REFLEXes.Methods: Sixteen normal subjects voluntarily participated in this study and were randomly allocated. Subjects were remained in prone position. The cutaneous mechanical pressure (CMP) equal to 50% of leg and foot weight was applied to the ipsilateral lateral plantar surface using a special instrument through a square plate (30x30 mm). H reflexes as indicator for excitability of motoneurones was bilaterally elicited before and after the application of the CMP and the Hreflex parameters were measured.Results: The amplitude of H reflex and HIM ratio showed significant differences before and after the ipsilateral CMP stimulation of the lateral side of the foot (p<0.05; p<0.05, respectively decreased). Furthennore, the latencies of H reflexes were also increased (p<0.05).Conclusion: Our results highlight the modulatory effects of natural stimulation of cutaneous afferents on excitability of ipsilateral and contralateral motoneurones. This in respect may have practical application in the management of muscle tone disorders following brain and spinal cord injuries.

Background and Aim: Spinal manipulation is a treatment modality in the management of patients with pain in the neck, low back or pelvic disorders. The objective of this research was to determine the effects of sacroiliac joint manipulation on selected electrophysiological parameters including pressure pain thresholds (PPT) and Tibial nerve Hoffmann's reflex (H-REFLEX) amplitude.Materials and Methods: In this quasiexperimental study between 2009 and 2010, 20 healthy young female volunteers of Shiraz University Of Medical Sciences participated. Pressure pain threshold was measured from the posterior superior iliac spine and H.reflex recorded from the Tibial nerve of the same side were evaluated before and after sacroiliac joint manipulation. Hreflex for 20 and PPT for 15 minutes were recorded after manipulation. Data analysis was don e by means of SPSS (version 18), repeated measure analysis, and post-hoc Bonferroni.Results: Sacroiliac joint manipulation attenuated alpha motor neuronal activity significantly for 20 seconds (Mean±SD, 16±0.16) compared to before the technique (Mean=035±0.15), P =0.005. PPT values reduced in post manipulation versus pre manipulation; although there were statistically no significant differences in PPT based on recursive measuring test.Conclusion: Sacroiliac joint manipulation procedure produces a transient attenuation of alpha motor neuronal excitability. Probably, applying this technique cannot change pressure pain threshold. Manipulation can have a muscle tone reduction effect.

Background: Studying the H-REFLEX in electromyography of patients with radiculopathy is a routine and useful recommended technique for treatment of the disease and is somehow pathognomic for S1 radiculopathy. Researchers have already mentioned that the shape of H- Reflex changes fallowing. changing the subjects positions. However, no academic study has focused on the relationship between these different positions and the changes of the amplitude or latency of their H-REFLEX. This study was performed to find out if the different low back positions, introduced by Mckenzie with respect to his claim of pain centralization following placing the patients in these positions, can effectively change the parameters of the H-REFLEX in patients with S1 radiculopathy.Materials and Methods: 15 subjects with unilateral S1 radiculopathy were recruited and tested in three positions named as the first, second and third Mckenzies low back positions. The parameters of their H-REFLEX were recorded by an electromyography apparatus.Results: The results of this study showed that the above- mentioned positions did not significantly change the required intensity to produce the M wave, amplitude and latency of the M wave and the HIM maximum amplitude ratio. However, the latency of H-REFLEX decreased significantly (P=0.031) and the amplitude of H-REFLEX increased (p=0.011) (3rd Mckenzies position in comparison with 1st position) the required intensity to produce maximum H-REFLEX was reduced (p=0.006).Conclusion: It can be concluded that different Mckenzie low back positions likely confirms his claim that these positions are able to reduce disc herniation and relieve the impinged nerve root in spinal nerve canal through providing a better anatomical position. This is not only results the centralization of pain, but influences on their Hreflex as the most important index of S1 radiculopathy and changes its amplitude and latency towards a more normal pattern.