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Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps.
J Strength Cond Res. 2015 Sep; 29(9):2482-7.JS

Abstract

The purposes of this study were to measure the acute effects of knee wraps (KWs) on knee and hip joint kinematics, dynamic muscle activation from the vastus lateralis (VL) and gluteus maximus (GM), and rating of perceived exertion (RPE) during the back squat exercise at 2 different intensities. Fourteen resistance-trained men (age: 24 ± 4 years, height: 176 ± 6 cm, body mass: 81 ± 11 kg, back squat 1 repetition maximum [1RM]: 107 ± 30 kg, 3 ± 1 year of back squat experience) performed 1 set of 3 repetitions under 4 different conditions, to a depth of approximately 90 degrees of knee joint flexion, and in random order: KWs at 60% 1RM (KW60), KWs at 90% 1RM (KW90), without knee wraps (NWs) at 60% 1RM (NW60), and NWs at 90% 1RM (NW90). The dependent variables obtained were vertical and horizontal bar displacement, peak joint angle in the sagittal plane (hip and knee joints), concentric and eccentric muscle activation (by integrated electromyography) from the VL and GM, and RPE. For muscle activity, there were significant decreases in the VL NWs at 60% 1RM (p = 0.013) and a significant increase NWs at 90% 1RM (p = 0.037). There was a significant increase in VL muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p = 0.001, effect size (ES) = 1.51 and NW: p < 00.001, ES = 1.67). There was a decrease in GM muscle activity NWs only at 60% 1RM (p = 0.014). There was a significant increase in GM muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p < 0.001 and NW: p < 0.001). For peak hip joint flexion angle, there was significant decreases between intensities (90% 1RM < 60% 1RM) only to NWs condition (p = 0.009), and there was greater knee flexion NWs for both intensities: 60% 1RM (p < 0.001) and 90% 1RM (p = 0.018). For normalized vertical barbell displacement, there were significant differences between intensities when using KWs (p = 0.022). There were significant differences in RPE between 60 and 90% 1RM for each condition: KWs (p < 0.001) and NWs (p < 0.001). In conclusion, the use of KWs results in decreased muscle activation of the VL at the same intensity (90% 1RM).

Authors+Show Affiliations

1Graduate Program in Science of Human Movement, College of Health Science (FACIS), Methodist University of Piracicaba, Piracicaba, São Paulo, Brazil; 2Department of Kinesiology, Center for Sport Performance, California State University, Fullerton, California; and 3Physical Education Department, Faculty Adventist of Hortolândia, Hortolândia, São Paulo, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Study
Journal Article

Language

eng

PubMed ID

25763519

Citation

Gomes, Willy A., et al. "Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps." Journal of Strength and Conditioning Research, vol. 29, no. 9, 2015, pp. 2482-7.
Gomes WA, Brown LE, Soares EG, et al. Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps. J Strength Cond Res. 2015;29(9):2482-7.
Gomes, W. A., Brown, L. E., Soares, E. G., da Silva, J. J., de O Silva, F. H., Serpa, É. P., Corrêa, D. A., Vilela Junior, G. d. e. . B., Lopes, C. R., & Marchetti, P. H. (2015). Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps. Journal of Strength and Conditioning Research, 29(9), 2482-7. https://doi.org/10.1519/JSC.0000000000000922
Gomes WA, et al. Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps. J Strength Cond Res. 2015;29(9):2482-7. PubMed PMID: 25763519.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps. AU - Gomes,Willy A, AU - Brown,Lee E, AU - Soares,Enrico G, AU - da Silva,Josinaldo J, AU - de O Silva,Fernando H D, AU - Serpa,Érica P, AU - Corrêa,Daniel A, AU - Vilela Junior,Guanis de B, AU - Lopes,Charles R, AU - Marchetti,Paulo H, PY - 2015/3/13/entrez PY - 2015/3/13/pubmed PY - 2016/4/19/medline SP - 2482 EP - 7 JF - Journal of strength and conditioning research JO - J Strength Cond Res VL - 29 IS - 9 N2 - The purposes of this study were to measure the acute effects of knee wraps (KWs) on knee and hip joint kinematics, dynamic muscle activation from the vastus lateralis (VL) and gluteus maximus (GM), and rating of perceived exertion (RPE) during the back squat exercise at 2 different intensities. Fourteen resistance-trained men (age: 24 ± 4 years, height: 176 ± 6 cm, body mass: 81 ± 11 kg, back squat 1 repetition maximum [1RM]: 107 ± 30 kg, 3 ± 1 year of back squat experience) performed 1 set of 3 repetitions under 4 different conditions, to a depth of approximately 90 degrees of knee joint flexion, and in random order: KWs at 60% 1RM (KW60), KWs at 90% 1RM (KW90), without knee wraps (NWs) at 60% 1RM (NW60), and NWs at 90% 1RM (NW90). The dependent variables obtained were vertical and horizontal bar displacement, peak joint angle in the sagittal plane (hip and knee joints), concentric and eccentric muscle activation (by integrated electromyography) from the VL and GM, and RPE. For muscle activity, there were significant decreases in the VL NWs at 60% 1RM (p = 0.013) and a significant increase NWs at 90% 1RM (p = 0.037). There was a significant increase in VL muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p = 0.001, effect size (ES) = 1.51 and NW: p < 00.001, ES = 1.67). There was a decrease in GM muscle activity NWs only at 60% 1RM (p = 0.014). There was a significant increase in GM muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p < 0.001 and NW: p < 0.001). For peak hip joint flexion angle, there was significant decreases between intensities (90% 1RM < 60% 1RM) only to NWs condition (p = 0.009), and there was greater knee flexion NWs for both intensities: 60% 1RM (p < 0.001) and 90% 1RM (p = 0.018). For normalized vertical barbell displacement, there were significant differences between intensities when using KWs (p = 0.022). There were significant differences in RPE between 60 and 90% 1RM for each condition: KWs (p < 0.001) and NWs (p < 0.001). In conclusion, the use of KWs results in decreased muscle activation of the VL at the same intensity (90% 1RM). SN - 1533-4287 UR - https://www.unboundmedicine.com/medline/citation/25763519/Kinematic_and_sEMG_Analysis_of_the_Back_Squat_at_Different_Intensities_With_and_Without_Knee_Wraps_ L2 - http://dx.doi.org/10.1519/JSC.0000000000000922 DB - PRIME DP - Unbound Medicine ER -