Decreased tibial nerve movement in patients with failed back surgery syndrome and persistent leg pain.

PURPOSE: To measure and compare the total and normalised tibial nerve movements during forward bending in patients with and without failed back surgery syndrome (FBSS) and persistent leg pain following anatomically successful lumbar decompression surgery and demonstrated no psychological stress. Nerve pathomechanics may contribute to FBSS with persistent leg pain following anatomically successful lumbar decompression surgery. METHODS: Tibial nerve movement during forward bending was measured in two groups of patients following anatomically successful lumbar decompression surgery. FBSS group (N = 37) consisted of patients with persistent leg pain following lumbar surgery, and non-FBSS (N = 37) were patients with no remaining leg pain following lumbar surgery. Total and normalised tibial nerve movement at the popliteal fossa was measured by a previously validated ultrasound imaging technique and compared between the two groups, and also between the painful and non-painful leg within the FBSS group. RESULTS: Both the mean total and normalised tibial nerve movement were significantly decreased in the FBSS group in both legs when compared to the non-FBSS group (P < 0.05). The total and normalised tibial nerve movements were also more restricted in the painful leg (P < 0.05) when compared to the non-painful side within the FBSS group. CONCLUSION: This was the first study to quantify the decreased total and normalised tibial nerve mobility in FBSS patients with persistent leg pain when compared with non-FBSS patients following anatomically successful lumbar decompression surgery. Further research could investigate the efficacy of intervention, such as nerve mobilisation in this particular group of patients with failed back surgery syndrome and limited nerve mobility. These slides can be retrieved under Electronic Supplementary Material.

Deep abdominal muscle activity following supratentorial stroke.

This study assessed the level and symmetry of deep abdominal muscle activation following a supratentorial stroke during a modified hip flexion task. Movement-related activation levels in the transversus abdominus (TrA) and internal oblique (IO) were investigated in people with a subacute (<3.25months) supratentorial stroke (n=11) and a matched control group (n=11). Electromyographic activity in TrA and IO were recorded using fine wires inserted under ultrasound guidance while participants performed a standardised head lift or unilateral hip flexion. During head lift there was no significant difference in the amplitude of activation ipsi- and contra-lateral to the stroke or between groups. During unilateral hip flexion the TrA and IO were activated more on both sides when moving the paretic leg. In the control group muscle activity was modulated by task with activity being higher ipsilateral to the moving leg; in contrast in the stroke group IO muscle activity tended to be higher on the non-paretic side irrespective of moving limb. Greater TrA and IO muscle activity during hip flexion of the paretic leg may represent compensatory activity that acts to facilitate activation of the paretic hip flexors and/or the presence of overflow.

Flameless atomic absorption spectrophotometry of selenium in fish and food products.

A method is described for determining selenium in fish tissues, meat, cereals, milk powder, and other materials by flameless atomic absorption spectrophotometry. Samples are solubilized in HNO3 and atomized in a graphite furnace in the presence of nickel nitrate. Recoveries of 0.500 and 1.000 microgram selenium added to several fish samples averaged 99.0 and 98.3%, respectively, with standard deviations of 5.3 and 4.0. Results agreed with those obtained for samples previously analyzed by fluorometry, and with results for NBS Standard Reference Material. The detection limit was 3 ng/ml solution and 50 ng/g sample.