{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T19:37:18Z","timestamp":1777405038811,"version":"3.51.4"},"reference-count":43,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T00:00:00Z","timestamp":1756684800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Runners have a high probability of sports injuries due to improper landing patterns. This study aimed to investigate the effects of three different foot strike patterns on lower limb muscle activation in healthy young male university students without specialized sports training experience. Methods: Sixteen healthy male college students (age: 21 \u00b1 1 years) participated in this study. They performed running with three different foot strike patterns: forefoot strike (FFS), midfoot strike (MFS), and rearfoot strike (RFS) at controlled speeds of 1.4\u20131.6 m\/s. EMG signals from six lower limb muscles (vastus lateralis, vastus medialis, rectus femoris, tibialis anterior, lateral gastrocnemius, and medial gastrocnemius) during the stance phase were collected using a wireless EMG system (1000 Hz). Ensemble Empirical Mode Decomposition (EEMD) was employed to analyze the time\u2013frequency characteristics of lower limb EMG signals and ankle joint co-activation patterns to investigate the corresponding neuromuscular control mechanisms. Statistical analyses were performed using repeated-measures ANOVA, and significance was set at p &lt; 0.05. Results: The timing of maximum energy in lower limb muscles during the stance phase occurred earlier in RFS compared to FFS and MFS. At initial ground contact, the low-frequency component energy (below 60 Hz) of the medial gastrocnemius was significantly higher in MFS and RFS compared to FFS, while FFS exhibited significantly higher high-frequency component energy (61\u2013200 Hz). The co-activation of ankle dorsiflexors and plantar flexors (TA\/GM) was also significantly higher in MFS and RFS compared to FFS. During the 100 ms before foot contact, the low-frequency component energy (below 60 Hz) of the lateral gastrocnemius was significantly higher in MFS compared to FFS, and the degree of TA\/GM co-activation was significantly higher in both MFS and RFS compared to FFS. Conclusions: The maximum frequency in lower limb muscles appeared earliest during the mid-stance phase in the rearfoot strike (RFS) pattern. Moreover, during the pre-activation and early stance phases, frequency differences were observed only in the medial gastrocnemius, with RFS showing significantly higher low-frequency power.<\/jats:p>","DOI":"10.3390\/life15091386","type":"journal-article","created":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T13:27:44Z","timestamp":1756733264000},"page":"1386","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Comparison of Time\u2013Frequency Characteristics of Lower Limb EMG Signals Among Different Foot Strike Patterns During Running Using the EEMD Algorithm"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-8010-9123","authenticated-orcid":false,"given":"Shuqiong","family":"Shi","sequence":"first","affiliation":[{"name":"School of Sport Science, Beijing Sport University, Beijing 100084, China"},{"name":"Key Laboratory of Exercise and Physical Fitness of Ministry of Education, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-5952-9515","authenticated-orcid":false,"given":"Xindi","family":"Ni","sequence":"additional","affiliation":[{"name":"School of Sport Science, Beijing Sport University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Loi","family":"Ieong","sequence":"additional","affiliation":[{"name":"School of Sport Science, Beijing Sport University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lei","family":"Li","sequence":"additional","affiliation":[{"name":"School of Sport Science, Beijing Sport University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ye","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Sport Science, Beijing Sport University, Beijing 100084, China"},{"name":"Laboratory of Sports Stress and Adaptation of General Administration of Sport, Beijing Sport University, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1325","DOI":"10.1249\/MSS.0b013e3182465115","article-title":"Foot strike and injury rates in endurance runners: A retrospective study","volume":"44","author":"Daoud","year":"2012","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/j.gaitpost.2023.10.019","article-title":"A new method proposed for realizing human gait pattern recognition: Inspirations for the application of sports and clinical gait analysis","volume":"107","author":"Xu","year":"2024","journal-title":"Gait Posture"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1177\/1941738120934715","article-title":"Effects of Foot Strike Techniques on Running Biomechanics: A Systematic Review and Meta-analysis","volume":"13","author":"Xu","year":"2021","journal-title":"Sports Health"},{"key":"ref_4","first-page":"132","article-title":"Neuromuscular tuning patterns of Running with Different Landing Methods: Time-frequency Analysis Based on Ground Reaction Forces","volume":"29","author":"Yang","year":"2022","journal-title":"J. Sports Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1016\/j.jelekin.2015.04.001","article-title":"Multi-muscle activation strategies during walking in female post-operative total joint replacement patients","volume":"25","author":"Kuntze","year":"2015","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.jneumeth.2011.07.008","article-title":"Muscular timing and inter-muscular coordination in healthy females while walking","volume":"201","author":"Huber","year":"2011","journal-title":"J. Neurosci. Methods"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1016\/j.jbiomech.2013.02.017","article-title":"Heel-strike in walking: Assessment of potential sources of intra- and inter-subject variability in the activation patterns of muscles stabilizing the knee joint","volume":"46","author":"Huber","year":"2013","journal-title":"J. Biomech."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Gopfert, B., Scharer, C., Tacchelli, L., Gross, M., Luthy, F., and Hubner, K. (2022). Frequency Shifts in Muscle Activation during Static Strength Elements on the Rings before and after an Eccentric Training Intervention in Male Gymnasts. J. Funct. Morphol. Kinesiol., 7.","DOI":"10.3390\/jfmk7010028"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1299","DOI":"10.1016\/0021-9290(94)90039-6","article-title":"Two strategies of transferring from sit-to-stand; the activation of monoarticular and biarticular muscles","volume":"27","author":"Doorenbosch","year":"1994","journal-title":"J. Biomech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1080\/02640414.2016.1159717","article-title":"Muscle co-activation and its influence on running performance and risk of injury in elite Kenyan runners","volume":"35","author":"Tam","year":"2017","journal-title":"J. Sports Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1016\/S1050-6411(00)00030-4","article-title":"Intensity analysis in time-frequency space of surface myoelectric signals by wavelets of specified resolution","volume":"10","year":"2000","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1016\/j.jelekin.2013.01.007","article-title":"Speed-dependent variation in the Piper rhythm","volume":"23","author":"Maurer","year":"2013","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_13","unstructured":"Jaitner, T., Janssen, D., Burger, R., and Wenzel, U. (2010, January 19\u201323). Identification of EMG frequency patterns in running by wavelet analysis and support vector machines. Proceedings of the ISBS Conference Proceedings Archive, Marquette, MI, USA."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3545","DOI":"10.3390\/s110403545","article-title":"A Review of Non-Invasive Techniques to Detect and Predict Localised Muscle Fatigue","volume":"11","author":"Sepulveda","year":"2011","journal-title":"Sensors"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"12431","DOI":"10.3390\/s130912431","article-title":"Surface electromyography signal processing and classification techniques","volume":"13","author":"Chowdhury","year":"2013","journal-title":"Sensors"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1098\/rspa.1998.0193","article-title":"The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis","volume":"454","author":"Huang","year":"1998","journal-title":"Proc. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.bspc.2006.03.003","article-title":"EMG signal filtering based on Empirical Mode Decomposition","volume":"1","author":"Andrade","year":"2006","journal-title":"Biomed. Signal Process. Control"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6945","DOI":"10.3934\/mbe.2020359","article-title":"Surface electromyography signal denoising via EEMD and improved wavelet thresholds","volume":"17","author":"Sun","year":"2020","journal-title":"Math. Biosci. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1016\/j.medengphy.2012.10.009","article-title":"Filtering of surface EMG using ensemble empirical mode decomposition","volume":"35","author":"Zhang","year":"2013","journal-title":"Med. Eng. Phys."},{"key":"ref_20","first-page":"1001","article-title":"Exercise muscle fatigue detection system implementation via wireless surface electromyography and empirical mode decomposition","volume":"2013","author":"Chang","year":"2013","journal-title":"Annu. Int. Conf. IEEE Eng. Med. Biol. Soc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1007\/s11517-022-02736-4","article-title":"Detection of intermuscular coordination based on the causality of empirical mode decomposition","volume":"61","author":"Maas","year":"2023","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compbiomed.2015.01.011","article-title":"Empirical mode decomposition analysis of near-infrared spectroscopy muscular signals to assess the effect of physical activity in type 2 diabetic patients","volume":"59","author":"Molinari","year":"2015","journal-title":"Comput. Biol. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1647","DOI":"10.1109\/JBHI.2013.2286408","article-title":"The progression of muscle fatigue during exercise estimation with the aid of high-frequency component parameters derived from ensemble empirical mode decomposition","volume":"18","author":"Liu","year":"2014","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"16332","DOI":"10.1109\/JSEN.2023.3279555","article-title":"Gesture recognition based on EEMD and cosine Laplacian eigenmap","volume":"23","author":"Li","year":"2023","journal-title":"IEEE Sens. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2165\/00007256-200030010-00001","article-title":"Measures of reliability in sports medicine and science","volume":"30","author":"Hopkins","year":"2000","journal-title":"Sports Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"16","DOI":"10.5334\/joc.72","article-title":"How many participants do we have to include in properly powered experiments? A tutorial of power analysis with reference tables","volume":"2","author":"Brysbaert","year":"2019","journal-title":"J. Cogn."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1507","DOI":"10.1080\/02640414.2023.2269357","article-title":"Publication bias, statistical power and reporting practices in the Journal of Sports Sciences: Potential barriers to replicability","volume":"41","author":"Mesquida","year":"2023","journal-title":"J. Sports Sci."},{"key":"ref_28","first-page":"13","article-title":"European recommendations for surface electromyography","volume":"8","author":"Hermens","year":"1999","journal-title":"Roessingh Res. Dev."},{"key":"ref_29","first-page":"888","article-title":"Foot strike patterns of runners at the 15-km point during an elite-level half marathon","volume":"21","author":"Hasegawa","year":"2007","journal-title":"J. Strength Cond. Res."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Xu, D., Zhou, H., Quan, W., Ma, X., Chon, T.-E., Fernandez, J., Gusztav, F., Kov\u00e1cs, A., Baker, J.S., and Gu, Y. (2024). New insights optimize landing strategies to reduce lower limb injury risk. Cyborg Bionic Syst., 5.","DOI":"10.34133\/cbsystems.0126"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Martinek, R., Ladrova, M., Sidikova, M., Jaros, R., Behbehani, K., Kahankova, R., and Kawala-Sterniuk, A. (2021). Advanced Bioelectrical Signal Processing Methods: Past, Present, and Future Approach-Part III: Other Biosignals. Sensors, 21.","DOI":"10.3390\/s21186064"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.aap.2016.04.036","article-title":"The co-contraction index of the upper limb for young and old adult cyclists","volume":"105","author":"Kiewiet","year":"2017","journal-title":"Accid. Anal. Prev."},{"key":"ref_33","first-page":"888","article-title":"Lower limb muscle activity during forefoot and rearfoot strike running techniques","volume":"9","author":"Landreneau","year":"2014","journal-title":"Int. J. Sports Phys. Ther."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"983","DOI":"10.1080\/17461391.2022.2081094","article-title":"Temporal differences in the myoelectric activity of lower limb muscles during rearfoot and forefoot running: A statistical parametric mapping approach","volume":"23","author":"Valencia","year":"2023","journal-title":"Eur. J. Sport Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1016\/j.humov.2012.11.005","article-title":"EMG and tibial shock upon the first attempt at barefoot running","volume":"32","author":"Olin","year":"2013","journal-title":"Hum. Mov. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1016\/j.bspc.2018.09.002","article-title":"A model computation of how synchronization and clustering of motor unit action potentials alter the power spectra of electromyograms","volume":"47","year":"2019","journal-title":"Biomed. Signal Process. Control"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Koenig, I., Eichelberger, P., Blasimann, A., Hauswirth, A., Baeyens, J.P., and Radlinger, L. (2018). Wavelet analyses of electromyographic signals derived from lower extremity muscles while walking or running: A systematic review. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0206549"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1682","DOI":"10.1152\/japplphysiol.91181.2008","article-title":"Last word on point:counterpoint: Spectral properties of the surface EMG can characterize\/do not provide information about motor unit recruitment strategies and muscle fiber type","volume":"105","author":"Nigg","year":"2008","journal-title":"J. Appl. Physiol."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Yong, J.R., Dembia, C.L., Silder, A., Jackson, R.W., Fredericson, M., and Delp, S.L. (2020). Foot strike pattern during running alters muscle-tendon dynamics of the gastrocnemius and the soleus. Sci. Rep., 10.","DOI":"10.1038\/s41598-020-62464-3"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"von Tscharner, V., Ullrich, M., Mohr, M., Comaduran Marquez, D., and Nigg, B.M. (2018). A wavelet based time frequency analysis of electromyograms to group steps of runners into clusters that contain similar muscle activation patterns. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0195125"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.jelekin.2010.10.004","article-title":"Piper rhythm of the electromyograms of the abductor pollicis brevis muscle during isometric contractions","volume":"21","author":"Barandun","year":"2011","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1152\/jn.00084.2018","article-title":"Muscle coactivation: Definitions, mechanisms, and functions","volume":"120","author":"Latash","year":"2018","journal-title":"J. Neurophysiol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1123\/ijspp.2018-0151","article-title":"Running Economy: Neuromuscular and Joint Stiffness Contributions in Trained Runners","volume":"14","author":"Tam","year":"2019","journal-title":"Int. J. Sports Physiol. Perform."}],"container-title":["Life"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-1729\/15\/9\/1386\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:37:17Z","timestamp":1760035037000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-1729\/15\/9\/1386"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,1]]},"references-count":43,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["life15091386"],"URL":"https:\/\/doi.org\/10.3390\/life15091386","relation":{},"ISSN":["2075-1729"],"issn-type":[{"value":"2075-1729","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,1]]}}}