Study Design: Single group pretest-posttest. Background: There is a lack of consensus concerning the preferred assessment and treatment for radial epicondylalgia. Objectives: Determine whether deficiencies in muscle force, joint range of motion, or painful force threshold are detected when measurements from the involved upper extremity are normalized to values from the uninvolved extremity. Methods and Measures: Ten patients (70% men) 42 ± 7 years in age with unilateral radial epicondylalgia participated. The visual analog pain scale and 6 measurements involving either muscle force, joint range of motion, or painful force threshold were examined. Results: When comparing the initial assessments to final assessments, a significant improvement was found for the visual analog pain scale (5 ± 3 versus 1 ± 3) and for the following normalized scores: grip (78 ± 26% versus 101 ± 20%) and isometric wrist extension forces (68 ± 24% versus 95 ± 35%), painful force threshold over the lateral epicondyle (49 ± 22% versus 94 ± 14%), and active wrist extension range of motion (83 ± 13% versus 96 ± 10%). Conclusions: Normalized force and range of motion measurements following treatment for unilateral radial epicondylalgia are sensitive assessments of patient progress. In comparison with measurements of force and range of motion that are not adjusted to a baseline score, normalized measurements detect changes in patient responses when baseline scores vary.

J Orthop Sports Phys Ther. 1999;29(11):668-676.

Key Words: lateral epicondylitis, normalized assessment, repetitive motion injury

Objective:To analytically determine dexamethasone and dexamethasone phosphate concentrations in plasma derived from proximal effluent venous blood, following cathodic iontophoresis.

Methods and Measures: Six volunteers received the following dexamethasone phosphate (2.5 ml, 4 mg/ml) treatments to their wrists on separate occasions: cathodic iontophoresis (4 mA, 10 minutes or 4 mA, 20 minutes), passive application (10 or 20 minutes). Plasma samples from the ipsilateral antecubital vein were obtained 10 minutes prior to and half way through the treatment (5 or 10 minutes), at the end of the treatment (10 or 20 minutes), and posttreatment (15, 30, 60, 90, and 120 minutes). The present investigation examined: (1) the sensitivity and linearity of extraction and analysis of dexamethasone and dexamethasone phosphate; (2) the necessity for determining both; and (3) the plasma levels from proximal effluent venous blood following cathodic iontophoresis. Results: The aggregate (n = 18) of the 6-point standard curves were linear for dexamethasone (r > 0.974) and dexamethasone

phosphate (r > 0.829). In vitro dephosphorylation of dexamethasone phosphate to dexamethasone occurred in plasma at 37°C and during freeze-thaw. Measurable dexamethasone or dexamethasone phosphate concentrations were absent at all time points and under all conditions in the human subjects.

Conclusions: These results demonstrate the sensitivity of the current assay and the need for evaluating both forms of the drug, as in vitro dephosphorylation results in the presence of dexamethasone and dexamethasone phosphate in samples. Absence of measurable dexamethasone or dexamethasone phosphate in the proximal effluent venous blood may require re-evaluation of the extent of drug delivery during the clinical iontophoresis of dexamethasone phosphate.

J Orthop Sports Phys Ther. 2002; 32(9):461–468.

Keywords: anti-inflammatory agents, cutaneous administration, pharmacokinetics, tissue distribution