Lower Limb Muscle Activity Adjustment and Lactate Variation in Response to Increased Speed with Proportional Resistance in Young Adults
- XPO Trainer, Lactate Levels, Fatigue, Low extremity musculature, Resistance Training, Sled Training. Constant Resistance
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Background: Various pathologies require physiotherapists to adjust therapy interventions, some of which are to reducing joint loads while strengthening the lower extremity musculature. Tools such as a sled can be used to accomplish a small load with high-repetition-resistance exercises.
Purpose: This study examined the impact of pushing a sled with regulated resistance on lower limb muscle activation and fatigue while walking and running.
Methods: The neuromuscular activity of the tibialis anterior (TA) and gastrocnemius (GA) muscles of thirty-six young adults were recorded using surface electromyography (EMG) and lactate data from a Nova Biomedical Lactate Plus meter. The sled used was the XPO Trainer, which maintains a steady resistance proportional to the user regardless of the forces applied to accelerate the sled. Baseline lactate was collected and followed by one of three protocols: run, run-push (RP), or walk-push (WP). Each included three trials over a 40 ft distance, during which EMG data were collected per trial, whereas lactate was collected following the completion of the appointed task.
Results: Repeated measures ANOVAs were performed, showing a considerable increase (P<0.05) in lactate levels between the WP and RP groups. Pushing the sled at both WP and RP speeds demonstrated substantial (P<0.05) neuromuscular modifications, primarily in the TA, followed by the GA, in comparison to running.
Conclusion: Pushing a constant resistance sled provoked distinct modifications in the lower limb musculature associated with speed. Running while pushing the sled elicits a higher blood lactate response associated with a longer maximal amplitude and a shorter time for muscle recruitment in the GA and TA muscles, all indicative of endurance-oriented exercise.
- Aduen, J., Bernstein, W. K., Khastgir, T., Miller, J., Kerzner, R., Bhatiani, A., Lustgarten, J., Bassin, A. S., Davidson, L., & Chernow, B. (1994). The use and clinical importance of a substrate-specific electrode for rapid determination of blood lactate concentrations. Jama, 272(21), 1678-1685. DOI: 10.1001/jama.1994.03520210062033
- Borotikar, B. S., & Sheehan, F. T. (2013). In vivo patellofemoral contact mechanics during active extension using a novel dynamic MRI-based methodology. Osteoarthritis and cartilage, 21(12), 1886-1894. DOI: 10.1016/j.joca.2013.08.023
- Cohen, Z. A., Roglic, H., Grelsamer, R. P., Henry, J. H., Levine, W. N., Van Mow, C., & Ateshian, G. A. (2001). Patellofemoral stresses during open and closed kinetic chain exercises: an analysis using computer simulation. The American journal of sports medicine, 29(4), 480-487. DOI: 10.1177/03635465010290041701
- DeMers, M. S., Pal, S., & Delp, S. L. (2014). Changes in tibiofemoral forces due to variations in muscle activity during walking. Journal of or-thopaedic research: official publication of the Or-thopaedic Research Society, 32(6), 769–776. DOI: 10.1002/jor.22601
- Guadagnin, E.C., Barbieri, F.A., Simieli, L., & Carpes, F.P. (2019). Is muscular and functional performance related to gait symmetry in older adults? A systematic review. Archives of Geron-tology and Geriatrics, 84, 1-6. doi: 10.1016/j.archger.2019.103899.
- Folland, J. P., Irish, C. S., Robert, J. C., Tarr, J. E., & Jones, D. A. (2002). Fatigue is not a nec-essary stimulus for strength gains during re-sistance training. British Journal of Sports Medi-cine, 36(5), 370–373. DOI: 10.1136/bjsm.36.5.370
- Hamlyn N, Behm DG, Young WB. Trunk muscle activation during dynamic weight-training exer-cises and isometric instability activities. J Strength Cond Res. 2007 Nov;21(4):1108-12. doi: 10.1519/R-20366.1. PMID: 18076231.Kawamori, Naoki & Newton, Robert & Nosaka, Ken. (2014). Effects of weighted sled towing on ground reac-tion force during the acceleration phase of sprint running. Journal of sports sciences, 32(12) DOI: 10.1080/02640414.2014.886129
- Lopez, P., Pinto, R. S., Radaelli, R., Rech, A., Grazioli, R., Izquierdo, M., & Cadore, E. L. (2018). Benefits of resistance training in physically frail elderly: a systematic review. Aging clinical and experimental research, 30(8), 889-899. DOI: 10.1007/s40520-017-0863-z
- Nicholson, V. P., McKean, M. R., & Burkett, B. J. (2015). Low-load high-repetition resistance train-ing improves strength and gait speed in mid-dle-aged and older adults. Journal of science and medicine in sport, 18(5), 596-600. DOI: 10.1016/j.jsams.2014.07.018
- Rosario, M. G. (2020). Neuromuscular timing modification in responses to increased speed and proportional resistance while pushing a sled in young adults. European Journal of Human Movement, 44, 50-66. DOI: 10.21134/eurjhm.2020.44.544.
- Rosario, M.G., & Mathis, M. (2020). Lower limb muscle activation and kinematics modifications of young healthy adults while pushing a variable resistance sled. Journal of Human Sport and Ex-ercise. DOI: 10.14198/jhse.2021.164.06
- Roos, P. E., Barton, N., & van Deursen, R. W. (2012). Patellofemoral joint compression forces in backward and forward running. Journal of bio-mechanics, 45(9), 1656-1660. DOI: 10.1016/j.jbiomech.2012.03.020
- Rossom, S., Smith, C., Thelen, D., Vanwanseele, B., Assche, D., & Jonkers, I. (2018). Knee Joint Loading in Healthy Adults During Functional Ex-ercises: Implications for Rehabilitation Guidelines. Journal of Orthopaedic And Sports Physical Therapy, 48(3), 162–173.DOI: 10.2519/jospt.2018.7459
- Saxby, D. J., Modenese, L., Bryant, A. L., Gerus, P., Killen, B., Fortin, K., Wrigley, T. V., Bennell, K. L., Cicuttini, F. M., & Lloyd, D. G. (2016). Tibio-femoral contact forces during walking, running and sidestepping. Gait & posture, 49, 78-85. DOI: 10.1016/j.jbiomech.2012.03.020
- Tenan, M. S., McMurray, R. G., Blackburn, B. T., McGrath, M., & Leppert, K. (2011). The relation-ship between blood potassium, blood lactate, and electromyography signals related to fatigue in a progressive cycling exercise test. Journal of Electromyography and Kinesiology, 21(1), 25-32. DOI: 10.1016/j.jelekin.2010.09.002