The Upper Limb Neurodynamic Test 1: intra- and inter-tester reliability for assessing Pain and Resistance

Introduction The Upper Limb Neurodynamic Tests assess the integrity of the brachial plexus, by moving the neural tissues and stimulating them mechanically. Although they are commonly used in the clinic, only a few studies have described their intra- and inter-tester reliability in asymptomatic subjects. Aim The aim of this study is to measure the intra- and inter-tester reliability of the Upper Limb Neurodynamic Test 1 (ULNT1) described by Butler, with respect to onset of pain (OP), submaximal pain (SP), first resistance (R1), and second resistance (R2), and the effect of several repetitions with asymptomatic subjects. Materials and methods 36 asymptomatic right-handed subjects were selected for the study. Inclusion criteria were: adult asymptomatic individuals with full range of motion (ROM) of upper limb joints. Exclusion criteria were: history of cervico-brachial pain on either arm or sign of local musculoskeletal dysfunction on the upper quadrant. Three blinded physiotherapists evaluated the dominant upper arm; the ROM was recorded with an electrogoniometer (Twin Axes SG110 of Penny & Giles Biometrics Ltd Gwent, UK). OP was defined as the moment when the first strain or discomfort was felt by the subject, while SP was defined as the moment when strain became excessive or painful. R1 was the point in the ROM where minor resistance was first appreciated by the examiner, while R2 was the location in range where maximum resistance was perceived. The three examiners performed five consecutive repetitions of the ULNT1; two physiotherapy students recorded the data. The order of entrance of the tester was randomised. Results Intra-tester reliability for R1 was good with an Intraclass Correlation Coefficient (ICC) ranging from 0.69 to 0.91, while the inter-tester reliability was fair for R1 [0.48, Standard Error (SE)=0.14], R2 (0.62, SE=0.011) and SP (0.64, SE=0.09), but good for OP (0.72, SE=0.011) using the data from all the three physiotherapists. If only the two more expert therapists are considered, the ICCs improved for both subject parameters (OP=0.79, SE=0.015; SP=0.82, SE=0.017). The effect of five repetitions was a progressive and meaningfully statistical improvement of range for all parameters, from the first to the final repetition (p=0.00). Discussion These results are in line with other studies on the reliability of Manual Therapy Tests, which generally show stronger intra- than inter-tester reliability, and with previous studies on the same test. Furthermore, we observed that UNLT1 intra- and inter-tester reliability increased in proportion to the years of experience of the physiotherapist. Conclusions The results of this study imply that the ULNT1 can be reliably used to compare the findings of the same physiotherapist across several sessions, but it could be less reliable for comparing the findings between different physiotherapists, at least on asymptomatic subjects. The progressive improvement of ROM attributed to repetitive ULNT1 opens an interesting perspective for using the Neurodynamic techniques as therapeutic procedures.