This study was done to find the efficacy of the contra-lateral single joint tensioner technique to measure changes in P1 range of knee extension on the affected side in seated slump’s test. Pre-test post-test group design was used. Sixty asymptomatic male and female subjects within age group of 20 to 30 years were involved in the study. Neurodynamic testing and sequence for seated slump’s test was performed for structural differentiation. Intervention was given for six days on the uninvolved side to determine the effect contra-lateral single joint tensioner technique on the involved side. Pre and post readings of knee extension range of motion (P1) were noted on the involved extremity. One week after intervention, seated slump’s test was performed again on the involved extremity of subject and P1 was noted to find the longevity of the treatment manoeuvre. The results of study revealed there was a significant difference in the range of knee extension (P1) in asymptomatic adults. Therefore, we can ascertain that contra-lateral neurodynamic (tensioner) technique resulted in significant, long lasting improvement in knee extension range (P1) in asymptomatic young adults and promoting extensibility of sciatic nerve.