The Activation Pattern of Trunk and Lower Limb Muscles in an Electromyographic Assessment; Comparison Between Ground and Treadmill Walking

Background

Due to biomechanical differences, various patterns of muscle contraction are expected to occur while walking over ground versus when walking on a treadmill.

Objectives

This study aimed to compare amplitude and duration of activation of selected trunk and lower extremity muscles during over-ground and treadmill walking.

Materials and Methods

Through a simple sampling method, 19 sedentary healthy men within the age range of 20 - 40 were selected. Surface electromyography of rectus abdominis, external oblique, longissimus and multifidus muscles as the selected trunk muscles and vastus medialis, vastus lateralis and hamstrings as the selected lower limb muscles were recorded.

Results

In each gait cycle, there were no statistically significant differences in duration of selected trunk as well as lower limb muscles activity between treadmill and over-ground walking. However the mean amplitude of rectus abdominis (P = 0.005), longissimus (P = 0.018) and multifidus (P = 0.044) as the selected trunk muscles as well as the mean amplitude of vastus lateralis (P = 0.005) and vastus medialis (P < 0.001) as the lower limb muscles was greater on treadmill compared with over ground.

Conclusions

Due to the stabilizing role of trunk and lower limb muscles during walking, these muscles seem to be active throughout the entire gait cycle. The increased muscle amplitude on treadmill can demonstrate that more motor units may be recruited during the contraction, which can be helpful in prescribing the appropriate type of exercise especially for patients with core muscle weakness.

Comparison of Isometric Strength of the Trunk and Hip Muscle Groups in Female Athletes with and without Low Back Pain: A Cross-Sectional Study

Background: Low back pain (LBP) is a common musculoskeletal disorder in athletes. Reduced strength in hip and trunk muscles has been observed among non-athletes with low back pain. This study aimed to compare the strength of trunk and hip muscles between female athletes with and without LBP and to investigate strength association with disability level in female athletes with LBP. Methods: This cross-sectional study was conducted on 26 female athletes with LBP and 30 female athletes without LBP. The strength of the trunk and hip muscles was measured using a hand-held dynamometer and the impact of LBP on the sports activities and activities of daily living was measured using the Athletes Disability Index (ADI). Data analysis was done using an independent sample t test and the Pearson correlation coefficient. Results: There were no significant differences between groups for trunk and hip muscles strength (p > 0.05). A fair to moderate correlation was seen between the strength of the trunk, hip abductors, flexor and extensors muscles and the scores of the ADI questionnaire in the LBP group (r = -0.26 to -0.48). However, there was no significant correlation between the strength of hip adductor muscles and the scores on the ADI questionnaire. Conclusion: Based on the results, the strength of trunk and hip muscles was not different between athletes with and without LBP. It is recommended that athletes' training be done during functional tasks rather than strengthening a single muscle group.

Influence of Changing Hip Position on Electromyographic Activities of Selected Trunk Muscles During Bridging Exercises in Healthy Subjects: A Cross-Sectional Study

OBJECTIVE

The purpose of this study was to investigate how rectus abdominis, external oblique (EO), internal oblique (IO), erector spinae, multifidus (MF), and gluteus maximus (GMax) muscle activities change with different hip positions during back and side bridging exercises.

METHODS

Thirty-six healthy individuals participated in this cross-sectional study and performed 6 exercises including back bridging (BB) in neutral hip position, BB with internal rotation, BB with external rotation (BB + ER), side bridging with hips in neutral (SB), side bridging with hips in flexion (SB + HF), and side bridging with hips in extension (SB + HE). Muscle activity was observed using surface electromyography, normalized using maximum voluntary isometric contraction. Repeated-measures 1-way analysis of variance compared muscle readings for each position.

RESULTS

Back bridging with internal rotation showed significant differences in EO (P = .01) and IO (P < .001) compared with other BB positions. Multifidus and GMax differed significantly in BB + ER (P = .04). Side bridging exhibited significant differences in EO (P = .02; P < .001) and IO (P < .001) compared with the other 2 SB positions, with peak in SB + HF. Erector spinae, MF, and GMax also differed significantly (P < .001, P = .02, P < .001, respectively) with peak in SB + HE.

CONCLUSION

The findings revealed that EO and IO muscles were most active during BB with internal rotation, whereas the MF and GMax muscles were most active during BB + ER. In terms of SB, the EO and IO muscles were most active with either SB + HF or SB + HE, whereas the erector spinae, MF, and GMax muscles were most active with SB + HE.