Objective: To compare the stretching induced strength changes between the proximal and distal groups of muscles. Methods: Twenty-eight recreationally active male individuals participated in this study. They were assigned into Group A for proximal muscle (hamstring) and group B for distal muscle (calf) with 14 subjects in each group. This study is an experimental trial of selfstretching for 2 minutes (SS 2). This stretch duration involved a 30 second stretch and a 20 second relaxation period, intermittently. Maximum Isometric Voluntary Contraction Force (MIVCF) was measured in both groups before (pretest) and immediately after (posttest) stretching. Change in pre-stretching and immediately post-stretching MIVCF was compared between the two groups. Results: Maximum Isometric Voluntary Contraction Force increased with SS 2 in the hamstring by 1.31% and in calf muscle, it increased by 2.92%. However, these changes were statistically insignificant between the two groups (p>0.05). Conclusion: Shorter stretching (2 minute) increases maximum isometric voluntary contraction force in both muscles but relatively more in the calf.

Background: Different researchers have studied the effects of different types of stretching on different muscle groups. Since distal muscles are fully activated and proximal muscles are sub-optimally activated; thus, we might see different responses to stretching in the proximal and distal groups of muscles depending on their muscle activation. Therefore, this study aimed to compare the acute effects of 2, 4, and 8 minutes of intermittent static stretching (SS) on the isometric maximum voluntary contraction force (MVCF) of proximal (Hamstring) and distal (Calf) groups of muscles.Methods: Two groups pretest-posttest experimental design was used. A total of thirty participants were randomly assigned into two groups, and twenty-eight completed the intervention. In both groups, participants participated in three experimental trials (SS 2 , SS 4, and SS 8 ) on 3 days. 2-minute intermittent stretching (SS 2 ) was performed on day-I, 4-minute (SS 4 ) on day II, and 8-minute (SS 8 ) on day III. Isometric MVCF was measured at pre-intervention, 0-, 10-, and 20-minute post-intervention periods in both groups.Results: In the proximal group: SS 2 , SS 4 , and SS 8 did not affect isometric MVCF at the 0-, 10-, and 20-minute post-intervention periods (P > .05). In distal group: SS 2 did not affect isometric MVCF at 0-and 10-minute post-intervention periods (P > .05), however at 20-minute, MVCF increased by 11.06% (P < .05). SS 4 and SS 8 also did not alter isometric MVCF in the Calf at 0-, 10-, and 20-minute post-intervention periods (P > .05). No significant differences were observed between the proximal and distal groups (P > .05).Conclusion: 2-, 4-, and 8-minute intermittent SS did not affect the isometric strength in both muscle groups. In addition, proximal and distal groups of muscles responded similarly to three different duration intermittent SS.Abbreviations: AROM = active range of motion, MVCF = maximum voluntary contraction force, ROM = range of motion, SS = static stretching, SS 2 = static stretching for 2 minutes, SS 4 = static stretching for 4 minutes, SS 8 = static stretching for 8 minutes.