{"id":2746,"date":"2004-03-01T11:00:47","date_gmt":"2004-03-01T10:00:47","guid":{"rendered":"http:\/\/www.mapeisport.it\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/"},"modified":"2023-03-20T13:42:37","modified_gmt":"2023-03-20T12:42:37","slug":"acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps","status":"publish","type":"attivita-scientifica","link":"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/","title":{"rendered":"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps"},"content":{"rendered":"<p>Impellizzeri FM <sup>1<\/sup>, Marcora SM <sup>2<\/sup>, Sassi A <sup>1<\/sup>, Mognoni P<sup>3<\/sup>, Rampinini E <sup>1<\/sup><\/p>\n<p>1, Human Performance Lab, Sport Service MAPEI, Castellanza, Italy; 2, School of Sport, Health, and Exercise Sciences, University of Wales-Bangor, United Kingdom; 3, \u00a0Institute of Molecular Bioimaging and Physiology, National Research Council, Segrate, Italy<\/p>\n<p style=\"text-align: justify;\"><strong>Introduction<\/strong> Fatigue has been suggested as a risk factor for developing lower limbs injuries. In fact, higher injuries rate occurs in the last minutes of sports or recreational activities sessions. Furthermore, muscle fatigue decreases the dynamic stability of the knee and alters the neuromuscular control of the lower limb1, 2. Some evidences also suggest that lower limbs strength imbalance can increase the risk of injuries3. However, these factors have been investigated singularly, but no studies have examined the interaction between fatigue and lower limbs strength asymmetry. The aim of this study was to evaluate the acute effect of fatigue on bilateral lower limbs strength asymmetry measured using the peak of force developed during vertical jumps. <strong>Methods<\/strong> Twenty-six athletes (23 competitive alpine skiers and 3 tennis players) were tested during the pre-season period. Bilateral lower limbs strength asymmetry was determined from the peak of force measured during countermovement vertical jumps on a force platform. Jumps were performed using both lower limbs but with one foot on the platform and the other one on a levelled surface. A total of 10 jumps (five measures for each leg) were collected and the average peak of force of the best three jumps were used. Bilateral lower limbs strength asymmetry was expressed as the percent difference between the stronger and the weaker limbs. The sign \u2018-\u2018 indicated a stronger left leg while the sign \u2018+\u2019 a stronger right leg. This bilateral lower limbs strength asymmetry index was found to be significantly correlated to the that determined using the peak of force measured during maximal voluntary isometric contraction on a leg press at a knee angle of 100\u00b0 (r=0.84, p&lt;0.01, n=35). The reliability determined on 60 subjects using the Bland and Altman\u2019s limits of agreement showed a bias of 0.48% and a total error of 6.94% (Impellizzeri et al., manuscript in preparation).\u00a0 The bilateral lower limbs strength asymmetry was determined before and immediately after an exercise designed to induce muscle fatigue (45 s of continuous countermovement jumps).\u00a0 The Bland and Altman\u2019s limits of agreement was used to evaluate the individual differences in the bilateral lower limbs strength asymmetry before and after fatigue. <strong>Results<\/strong> After the 45 s jumps test, both the right and left lower limbs peak force decreased by 16%, from 1044 \u00b1 258 N to 877 \u00b1 228 N (p&lt;0.05), and from 1026 \u00b1 225 N to 860 \u00b1 190 N (p&lt;0.05), respectively. The difference between changes was significant (p&lt;0.05). Consequently, the mean bilateral lower limbs strength asymmetry before and after fatigue did not resulted significantly different (1.68 \u00b1 8.3% vs 1.65 \u00b1 11.4%, respectively). The peak lactate reached 5 min after the end of the 45 s jumps test was 7.45 \u00b1 1.13 mmol\u00b7L-1. The Bland and Altman\u2019s plot of the individual differences in the bilateral lower limbs strength asymmetry before and after fatigue (0.07 \u00b1 11.4%), compared to the limits of agreement of the reliability. <strong>Discussion<\/strong> The exercise protocol used (45 s of continuous jumps) was effective in inducing fatigue, but not in determining interaction between fatigue and bilateral lower limbs strength asymmetry.\u00a0 However, fatigue caused an increase of measurement variability.\u00a0 In fact, after the fatiguing protocol,\u00a0 some subjects demonstrated a change in lower limbs strength asymmetry larger than the one expected from the limits of agreement obtained in the reliability study. This suggests that fatigue might have had an effect in this subset of subjects.\u00a0 However, the exact origin of this increase variability (physiological or chance) requires additional investigation. Consequently, in absence of a clear explanation of this higher variability, we recommend to measure lower limbs strength asymmetry in non-fatiguing condition. <strong>References<\/strong> 1.\u00a0\u00a0\u00a0 Wojtys EM, Wylie BB, Huston LJ. The effects of muscle fatigue on neuromuscular function and anterior tibial translation in healthy knees. Am J Sports Med 1996; 24(5): 615-21 2.\u00a0\u00a0\u00a0\u00a0 Hiemstra LA, Lo IK, Fowler PJ. Effect of fatigue on knee proprioception: implications for dynamic stabilization. J Orthop Sports Phys Ther 2001; 31(10): 598-605 3.\u00a0 Dvorak J, Junge A. Football injuries and physical symptoms. A review of the literature. Am J Sports Med 2000; 28(5 Suppl): S3-9<\/p>\n<p>Comunicazione al Convegno Isokinetic 2004<\/p>\n","protected":false},"featured_media":0,"template":"","categories":[859],"tags":[192,197,908],"class_list":["post-2746","attivita-scientifica","type-attivita-scientifica","status-publish","hentry","category-testing-en","tag-aldo-sassi-en","tag-ermanno-rampinini-en","tag-franco-impellizzeri-en"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.1.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps - Mapei Sport<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps - Mapei Sport\" \/>\n<meta property=\"og:description\" content=\"Impellizzeri FM 1, Marcora SM 2, Sassi A 1, Mognoni P3, Rampinini E 1 1, Human Performance Lab, Sport Service MAPEI, Castellanza, Italy; 2, School of Sport, Health, and Exercise Sciences, University of Wales-Bangor, United Kingdom; 3, \u00a0Institute of Molecular Bioimaging and Physiology, National Research Council, Segrate, Italy Introduction Fatigue has been suggested as a [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/\" \/>\n<meta property=\"og:site_name\" content=\"Mapei Sport\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/MapeiSport\/\" \/>\n<meta property=\"article:modified_time\" content=\"2023-03-20T12:42:37+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:site\" content=\"@MapeiSport\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/\",\"url\":\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/\",\"name\":\"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps - Mapei Sport\",\"isPartOf\":{\"@id\":\"http:\/\/www.mapeisport.it\/#website\"},\"datePublished\":\"2004-03-01T10:00:47+00:00\",\"dateModified\":\"2023-03-20T12:42:37+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.mapeisport.it\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps\"}]},{\"@type\":\"WebSite\",\"@id\":\"http:\/\/www.mapeisport.it\/#website\",\"url\":\"http:\/\/www.mapeisport.it\/\",\"name\":\"Mapei Sport\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"http:\/\/www.mapeisport.it\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps - Mapei Sport","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.mapeisport.it\/en\/attivita-scientifica\/acute-effect-of-fatigue-on-bilateral-lower-limbs-strength-asymmetry-measured-using-vertical-jumps\/","og_locale":"en_US","og_type":"article","og_title":"Acute effect of fatigue on bilateral lower limbs strength asymmetry measured using vertical jumps - Mapei Sport","og_description":"Impellizzeri FM 1, Marcora SM 2, Sassi A 1, Mognoni P3, Rampinini E 1 1, Human Performance Lab, Sport Service MAPEI, Castellanza, Italy; 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