When I started to work on the video tool that measures vertical jump, I had to dust off my old textbooks to learn about the relationship between hang time and jump height. And to my surprise, it turned out that the vertical jump is a great (and interesting!) example of the laws of physics at work. You can really learn about the relationship between velocity, acceleration, forces and hang time. Definitely more interesting than the average example of your physics textbook!
Bought this as a training aid for my track team and so far no complaints it really does what i need it to do. I would recommend you come up with some drills when you buy this because if you improperly use it could injure the athlete you can not wing it with this. i like to you use it for warms ups or for specific strength training for my better athletes.
Shock and Vibration is archived in Portico, which provides permanent archiving for electronic scholarly journals, as well as via the LOCKSS initiative. It operates a fully open access publishing model which allows open global access to its published content. This model is supported through Article Processing Charges. For more information on Article Processing charges in general, click here.
!function(n,t){function r(e,n){return Object.prototype.hasOwnProperty.call(e,n)}function i(e){return void 0===e}if(n){var o={},u=n.TraceKit,s=[].slice,a="?";o.noConflict=function(){return n.TraceKit=u,o},o.wrap=function(e){function n(){try{return e.apply(this,arguments)}catch(e){throw o.report(e),e}}return n},o.report=function(){function e(e){a(),h.push(e)}function t(e){for(var n=h.length-1;n>=0;--n)h[n]===e&&h.splice(n,1)}function i(e,n){var t=null;if(!n||o.collectWindowErrors){for(var i in h)if(r(h,i))try{h[i].apply(null,[e].concat(s.call(arguments,2)))}catch(e){t=e}if(t)throw t}}function u(e,n,t,r,u){var s=null;if(w)o.computeStackTrace.augmentStackTraceWithInitialElement(w,n,t,e),l();else if(u)s=o.computeStackTrace(u),i(s,!0);else{var a={url:n,line:t,column:r};a.func=o.computeStackTrace.guessFunctionName(a.url,a.line),a.context=o.computeStackTrace.gatherContext(a.url,a.line),s={mode:"onerror",message:e,stack:[a]},i(s,!0)}return!!f&&f.apply(this,arguments)}function a(){!0!==d&&(f=n.onerror,n.onerror=u,d=!0)}function l(){var e=w,n=p;p=null,w=null,m=null,i.apply(null,[e,!1].concat(n))}function c(e){if(w){if(m===e)return;l()}var t=o.computeStackTrace(e);throw w=t,m=e,p=s.call(arguments,1),n.setTimeout(function(){m===e&&l()},t.incomplete?2e3:0),e}var f,d,h=[],p=null,m=null,w=null;return c.subscribe=e,c.unsubscribe=t,c}(),o.computeStackTrace=function(){function e(e){if(!o.remoteFetching)return"";try{var t=function(){try{return new n.XMLHttpRequest}catch(e){return new n.ActiveXObject("Microsoft.XMLHTTP")}},r=t();return r.open("GET",e,!1),r.send(""),r.responseText}catch(e){return""}}function t(t){if("string"!=typeof t)return[];if(!r(j,t)){var i="",o="";try{o=n.document.domain}catch(e){}var u=/(.*)\:\/\/([^:\/]+)([:\d]*)\/{0,1}([\s\S]*)/.exec(t);u&&u[2]===o&&(i=e(t)),j[t]=i?i.split("\n"):[]}return j[t]}function u(e,n){var r,o=/function ([^(]*)\(([^)]*)\)/,u=/['"]?([0-9A-Za-z\$_]+)['"]?\s*[:=]\s*(function|eval|new Function)/,s="",l=10,c=t(e);if(!c.length)return a;for(var f=0;f0?u:null}function l(e){return e.replace(/[\-\[\]{}()*+?.,\\\^\$|#]/g,"\\\$&")}function c(e){return l(e).replace("<","(?:<|<)").replace(">","(?:>|>)").replace("&","(?:&|&)").replace('"','(?:"|")').replace(/\s+/g,"\\s+")}function f(e,n){for(var r,i,o=0,u=n.length;or&&(i=u.exec(o[r]))?i.index:null}function h(e){if(!i(n&&n.document)){for(var t,r,o,u,s=[n.location.href],a=n.document.getElementsByTagName("script"),d=""+e,h=/^function(?:\s+([\w\$]+))?\s*\(([\w\s,]*)\)\s*\{\s*(\S[\s\S]*\S)\s*\}\s*\$/,p=/^function on([\w\$]+)\s*\(event\)\s*\{\s*(\S[\s\S]*\S)\s*\}\s*\$/,m=0;m]+)>|([^\)]+))\((.*)\))? in (.*):\s*\$/i,o=n.split("\n"),a=[],l=0;l=0&&(g.line=v+x.substring(0,j).split("\n").length)}}}else if(o=d.exec(i[y])){var _=n.location.href.replace(/#.*\$/,""),T=new RegExp(c(i[y+1])),E=f(T,[_]);g={url:_,func:"",args:[],line:E?E.line:o[1],column:null}}if(g){g.func||(g.func=u(g.url,g.line));var k=s(g.url,g.line),A=k?k[Math.floor(k.length/2)]:null;k&&A.replace(/^\s*/,"")===i[y+1].replace(/^\s*/,"")?g.context=k:g.context=[i[y+1]],h.push(g)}}return h.length?{mode:"multiline",name:e.name,message:i[0],stack:h}:null}function y(e,n,t,r){var i={url:n,line:t};if(i.url&&i.line){e.incomplete=!1,i.func||(i.func=u(i.url,i.line)),i.context||(i.context=s(i.url,i.line));var o=/ '([^']+)' /.exec(r);if(o&&(i.column=d(o[1],i.url,i.line)),e.stack.length>0&&e.stack[0].url===i.url){if(e.stack[0].line===i.line)return!1;if(!e.stack[0].line&&e.stack[0].func===i.func)return e.stack[0].line=i.line,e.stack[0].context=i.context,!1}return e.stack.unshift(i),e.partial=!0,!0}return e.incomplete=!0,!1}function g(e,n){for(var t,r,i,s=/function\s+([_\$a-zA-Z\xA0-\uFFFF][_\$a-zA-Z0-9\xA0-\uFFFF]*)?\s*\(/i,l=[],c={},f=!1,p=g.caller;p&&!f;p=p.caller)if(p!==v&&p!==o.report){if(r={url:null,func:a,args:[],line:null,column:null},p.name?r.func=p.name:(t=s.exec(p.toString()))&&(r.func=t[1]),"undefined"==typeof r.func)try{r.func=t.input.substring(0,t.input.indexOf("{"))}catch(e){}if(i=h(p)){r.url=i.url,r.line=i.line,r.func===a&&(r.func=u(r.url,r.line));var m=/ '([^']+)' /.exec(e.message||e.description);m&&(r.column=d(m[1],i.url,i.line))}c[""+p]?f=!0:c[""+p]=!0,l.push(r)}n&&l.splice(0,n);var w={mode:"callers",name:e.name,message:e.message,stack:l};return y(w,e.sourceURL||e.fileName,e.line||e.lineNumber,e.message||e.description),w}function v(e,n){var t=null;n=null==n?0:+n;try{if(t=m(e))return t}catch(e){if(x)throw e}try{if(t=p(e))return t}catch(e){if(x)throw e}try{if(t=w(e))return t}catch(e){if(x)throw e}try{if(t=g(e,n+1))return t}catch(e){if(x)throw e}return{mode:"failed"}}function b(e){e=1+(null==e?0:+e);try{throw new Error}catch(n){return v(n,e+1)}}var x=!1,j={};return v.augmentStackTraceWithInitialElement=y,v.guessFunctionName=u,v.gatherContext=s,v.ofCaller=b,v.getSource=t,v}(),o.extendToAsynchronousCallbacks=function(){var e=function(e){var t=n[e];n[e]=function(){var e=s.call(arguments),n=e[0];return"function"==typeof n&&(e[0]=o.wrap(n)),t.apply?t.apply(this,e):t(e[0],e[1])}};e("setTimeout"),e("setInterval")},o.remoteFetching||(o.remoteFetching=!0),o.collectWindowErrors||(o.collectWindowErrors=!0),(!o.linesOfContext||o.linesOfContext<1)&&(o.linesOfContext=11),void 0!==e&&e.exports&&n.module!==e?e.exports=o:"function"==typeof define&&define.amd?define("TraceKit",[],o):n.TraceKit=o}}("undefined"!=typeof window?window:global)},"./webpack-loaders/expose-loader/index.js?require!./shared/require-global.js":function(e,n,t){(function(n){e.exports=n.require=t("./shared/require-global.js")}).call(n,t("../../../lib/node_modules/webpack/buildin/global.js"))}});
The back squat and jump squat are the two most commonly-used strength training exercises for increasing vertical jump height. The back squat is clearly more effective for improving maximum force, while the jump squat can be used to shift the force-velocity gradient towards a more “velocity-oriented” profile when required. In addition, the jump squat has the secondary benefit of training force production right through until the muscles are contracting at short lengths, because of its longer acceleration phase. Even so, it is unclear whether squat variations are optimal for improving vertical jump height, because the center of mass is in a different place from in the vertical jump.
When I was growing up, basketball was big in my neighborhood. Everyone wanted to be able to dunk on a regulation 10-foot high basket and, thus, everyone focused on improving their vertical jump. The progression usually went a little something like this: touch the rim, grab the rim, hang on the rim, dunk with a volleyball and, finally, dunk with a basketball!
A total of 1679 patients were enrolled — 858 in the dopamine group and 821 in the norepinephrine group (Figure 1). All patients were followed to day 28; data on the outcome during the stay in the hospital were available for 1656 patients (98.6%), data on the 6-month outcome for 1443 patients (85.9%), and data on the 12-month outcome for 1036 patients (61.7%). There were no significant differences between the two groups with regard to most of the baseline characteristics (Table 1); there were small differences, which were of questionable clinical relevance, in the heart rate, partial pressure of arterial carbon dioxide (PaCO2), arterial oxygen saturation (SaO2), and ratio of partial pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FIO2). The type of shock that was seen most frequently was septic shock (in 1044 patients [62.2%]), followed by cardiogenic shock (in 280 patients [16.7%]) and hypovolemic shock (in 263 patients [15.7%]). The sources of sepsis are detailed in Table 2 in the Supplementary Appendix. Hydrocortisone was administered in 344 patients who received dopamine (40.1%) and in 326 patients who received norepinephrine (39.7%). Among patients with septic shock, recombinant activated human protein C was administered in 102 patients in the dopamine group (18.8%) and 96 patients in the norepinephrine group (19.1%).
On the basis of the results of the SOAP study,3 which showed a rate of death of 43% among patients receiving dopamine and a rate of 36% among patients receiving norepinephrine, we estimated that with 765 patients in each group, the study would have 80% power to show a 15% relative difference in the rate of death at 28 days, at a two-sided alpha level of 0.05.
Also, using the lifting (concentric) phase of these exercises only, rather than both lowering and lifting phases, *might* further improve results. This is partly because lifting phases involve faster rate coding, and partly because this strategy might potentially help avoid optimizing stretch-shortening cycle function for lifting heavy weights, rather than for jumping.
A Tomahawk dunk can be performed with one or two hands, and when two hands are used, it is called a backscratcher. During the jump, the ball is raised above, and often behind the player's head for a wind-up before slamming the ball down into the net at the apex of the jump. Due to the undemanding body mechanics involved in execution, the tomahawk is employed by players of all sizes and jumping abilities.[citation needed] Because of the ball-security provided by the use of both hands, the two-handed tomahawk is a staple of game situations—frequently employed in alley-oops and in offense-rebound put-back dunks.
The between-the-legs dunk was popularized by Isaiah Rider in the 1994 NBA slam dunk contest,[12] so much so that the dunk is often colloquially referred to as a "Rider dunk" — notwithstanding Orlando Woolridge's own such dunk in the NBA contest a decade earlier.[13] Since then, the under-the-leg has been attempted in the NBA contest by a number of participants, and has been a staple of other contests as well. Its difficulty — due to the required hand-eye coordination, flexibility, and hang-time — keeps it generally reserved for exhibitions and contests, not competitive games. Ricky Davis has managed to complete the dunk in an NBA game,[14] but both he[15] and Josh Smith[16] have botched at least one in-game attempt as well.
Not so long ago, I played the worst basketball game of my life. I missed layups, turned over the ball, allowed my opponent free reign to the hoop. It was dark. As I slumped on the sidelines after the game, I realized how far I’d fallen from my prime a decade ago. Back then, I could dunk; now, at 33, I could barely curl my fingers over the rim. My game had regressed to hovering around the arc jacking threes. The last time I dunked a basketball, Michael Jordan was a Washington Wizard and people still listened to Coldplay.
Robert Cole, de The Times dijo: "Klein se burla del "complejo de desastres del capitalismo" y las ganancias y las privatizaciones que van con él, pero no proporciona una crítica convincente -que argumente sobre los principios del mercado libre-, y sin ésta, La doctrina del shock desciende en una maraña de historias que a menudo son preocupantes, a veces interesantes y, en ocasiones, extrañas".17​

When performing a vertical jump, the athlete exerts force at the low back, hip, knee, and ankle joints. The spine flexes as the athlete squats downwards, and then is extended by the spinal erectors over the course of the jump. The hip extensors (gluteus maximus, hamstrings, and adductor magnus) work to move the trunk and the thigh apart, which pushes the torso up and backwards. Meanwhile, the knee extensors (quadriceps) contract to extend the knee, and the calf muscles contract to move the shin backwards, towards the vertical.
The trial included 1679 patients, of whom 858 were assigned to dopamine and 821 to norepinephrine. The baseline characteristics of the groups were similar. There was no significant between-group difference in the rate of death at 28 days (52.5% in the dopamine group and 48.5% in the norepinephrine group; odds ratio with dopamine, 1.17; 95% confidence interval, 0.97 to 1.42; P=0.10). However, there were more arrhythmic events among the patients treated with dopamine than among those treated with norepinephrine (207 events [24.1%] vs. 102 events [12.4%], P<0.001). A subgroup analysis showed that dopamine, as compared with norepinephrine, was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1044 patients with septic shock or the 263 with hypovolemic shock (P=0.03 for cardiogenic shock, P=0.19 for septic shock, and P=0.84 for hypovolemic shock, in Kaplan–Meier analyses).
Vertical jump measurements are used primarily in athletic circles to measure performance. The most common sports in which one's vertical jump is measured are track and field, netball, basketball, football, and volleyball, but many sports measure their players' vertical jumping ability during physical examinations. In addition, single and multiple vertical jumps are occasionally used to assess muscular strength and anaerobic power in athletes.[3]