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59-397: Obtaining an armlock requires effective use of full-body leverage in order to initiate and secure a lock on the targeted arm, while preventing the opponent from escaping the lock. Therefore, performing an armlock is less problematic on the ground, from positions such as the mount , side control , or guard . Armlocks are more difficult to perform when both combatants are standing up, though

118-638: A ( F A ⋅ e A ⊥ ) − b ( F B ⋅ e B ⊥ ) = a F A − b F B , {\displaystyle F_{\theta }=\mathbf {F} _{A}\cdot {\frac {\partial \mathbf {v} _{A}}{\partial {\dot {\theta }}}}-\mathbf {F} _{B}\cdot {\frac {\partial \mathbf {v} _{B}}{\partial {\dot {\theta }}}}=a(\mathbf {F} _{A}\cdot \mathbf {e} _{A}^{\perp })-b(\mathbf {F} _{B}\cdot \mathbf {e} _{B}^{\perp })=aF_{A}-bF_{B},} where F A and F B are components of

177-426: A b . {\displaystyle MA={\frac {F_{2}}{F_{1}}}={\frac {a}{b}}.\!} This relationship shows that the mechanical advantage can be computed from ratio of the distances from the fulcrum to where the input and output forces are applied to the lever, assuming a weightless lever and no losses due to friction, flexibility or wear. This remains true even though the "horizontal" distance (perpendicular to

236-403: A b . {\displaystyle MA={\frac {F_{B}}{F_{A}}}={\frac {a}{b}}.} This is the law of the lever , which was proven by Archimedes using geometric reasoning. It shows that if the distance a from the fulcrum to where the input force is applied (point A ) is greater than the distance b from fulcrum to where the output force is applied (point B ), then the lever amplifies

295-406: A and b are distances from the fulcrum to points A and B and the force F A applied to A is the input and the force F B applied at B is the output, the ratio of the velocities of points A and B is given by a/b , so we have the ratio of the output force to the input force, or mechanical advantage, is given by: M A = F B F A =

354-493: A and b are the perpendicular distances between the forces and the fulcrum. Since the moments of torque must be balanced, T 1 = T 2 {\displaystyle T_{1}=T_{2}\!} . So, F 1 a = F 2 b {\displaystyle F_{1}a=F_{2}b\!} . The mechanical advantage of a lever is the ratio of output force to input force. M A = F 2 F 1 =

413-576: A mechanical advantage device , trading off force against movement. The word "lever" entered English around AD 1300 from Old French : levier . This sprang from the stem of the verb lever , meaning "to raise". The verb, in turn, goes back to Latin : levare , itself from the adjective levis , meaning "light" (as in "not heavy"). The word's primary origin is the Proto-Indo-European stem legwh- , meaning "light", "easy" or "nimble", among other things. The PIE stem also gave rise to

472-403: A submission hold or striking. There is a rough hierarchy of major ground grappling positions from the most advantageous to the least for the "top" fighter: A reversal from a dominant or top position is called a sweep ; these are usually the aim of a fighter in the bottom position, though there are some submissions that can be executed from the bottom, most commonly from the guard . While

531-401: A "seatbelt" securing the opponent. Though an effective lock, it is more difficult than other armlocks to successfully apply. The technique called a monoplata is a similar armlock that resembles jūji-gatame or spiderweb position yet has a mechanism like an omoplata. Tsunetane Oda, a judo groundwork specialist who died in 1955, was shown on video to have demonstrated the technique. A hammerlock

590-403: A cross. In general, the practitioner secures an arm at the wrist of the opponent, trapping it by squeezing the knees together. To initiate the submission one of the legs will be across the chest of the opponent, the second leg's calf will cross face the opponent, with the hips tight into the armpit, with the arm held between the thighs, with the elbow pointing against the thigh or hips. By holding

649-401: A fixed point. The lever operates by applying forces at different distances from the fulcrum, or a pivot. As the lever rotates around the fulcrum, points further from this pivot move faster than points closer to the pivot. Therefore, a force applied to a point further from the pivot must be less than the force located at a point closer in, because power is the product of force and velocity. If

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708-478: A judoka and a professional wrestler Masahiko Kimura used it to defeat one of the founders of Brazilian Jiu-Jitsu, Hélio Gracie . This variation of the name gained more prominence in MMA after the introduction of UFC, and the role Gracie had in its early history. Although a top wristlock is technically a reverse double wristlock, UFC announcer Bruce Buffer still announces fights won by top wristlock as "by tap-out due to

767-533: A kimura". The double wristlock is considered in catch wrestling to be the bread-and-butter part of their style. Professional wrestler Terry Funk credits Lorigo "Tony" Morelli with introducing the hold to wrestling "in the '20s", and expressed light frustration with the term "kimura" gradually replacing "double wristlock". He says Morelli set it up by giving opponents (either in fixed matches or legitimate challenges) his back, while standing, throughout his thirty-year career. A reporter for The Spokesman-Review used

826-414: A lever long enough and a fulcrum on which to place it, and I shall move the world." Autumn Stanley argues that the digging stick can be considered the first lever, which would position prehistoric women as the inventors of lever technology. A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in

885-407: A medial keylock known in judo as gyaku ude-garami (reverse arm entanglement) or simply as ude-garami . The application is similar to the top wristlock, except that it is reversed. It needs some space behind the opponent to be effective, and can be applied from the side control or guard. Contrary to the top wristlock, the opponent's wrist is grabbed with the hand on the same side, and the opposite arm

944-430: A neutral position if neither is in a more favourable position. If one party has a clear advantage such as in the mount they are said to be in a "dominant position". Conversely, the other party is considered to be in an inferior position, usually called "on the bottom", but in this case sometimes called the "under mount". Called clinch position or standing grappling position, these are the core of clinch fighting . From

1003-499: A position may be considered dominant in one sport, that may not be the case in another: for example, the closed guard in BJJ may be dominant in terms of submission; in mixed martial arts (MMA), however, where striking is allowed, while the guard still offers submission opportunities and defence, the fighter on top can strike better than the one on the bottom so the position is usually viewed as neutral in MMA and Budo Moussaraa MMA. Wrestling

1062-426: A separated stand-up position, a clinch is the result of one or both fighters applying a clinch hold . The process of attempting to advance into more dominant clinch positions is known as pummelling . Major types of standing clinches include: Fighters may attempt to break from the clinch, either as the rule requires it as in boxing or because they wish to obtain a better position by moving out and re-engaging, If

1121-409: Is a grappling keylock technique in which both of the practitioner's arms isolate and cause flexion to the shoulder , elbow , and to a lesser extent the wrist of the opponent. The technique is generally set in motion by the practitioner, using their opposite side hand (i.e. to target the opponents' right hand he uses his own left hand), pinning the opponent's arm to the ground at the wrist, so that

1180-425: Is a shoulder lock similar to the double wristlock where the opponent's arm is held bent against their back, and their hand forced upwards towards the neck, thereby applying pressure to the shoulder joint . This version of the rotational armlock has been present in wrestling circles for centuries and its earliest appearance is in a 16th century German book detailing techniques for European Wrestling. In BJJ circles, this

1239-405: Is another bent arm shoulder lock. The locking mechanism is similar to the kimura bent arm lock, but instead of using a figure-four, it is applied using a leg. The omoplata can be applied from the guard, by placing one leg under the opponent's armpit and turning 180 degrees in the direction of that leg, so that the leg moves over the back of the opponent and entangles the opponent's arm. By controlling

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1298-637: Is brought up to a twisting hammerlock, it becomes an illegal hold and must be stopped by the Referee...". Elsewhere, it prohibits preventing an opponent from escaping with a bodylock, with low-quality photographic illustration. It also noted concern for the danger of a legally applied double wristlock. Robin Reed had used the move to force pins on his way to an Olympic gold medal in 1924. The omoplata (referred to in judo as ashi-sankaku-garami , 三角絡み, "triangular entanglement" and in catch wrestling as coil lock )

1357-487: Is focused in stopping the strangle. The "shoulder lock" is a technique used as a method of upper body restraint. It should not be confused with a choke because the lock does not block or interfere with the flow of air or oxygen to the brain. The application is executed by applying pressure between the radial bone and shoulder. The top shoulder lock , (Also known as the figure-four armlock , bent armlock , americana , keylock , V1 armlock , paintbrush , or ude-garami )

1416-405: Is operated by applying an input force F A at a point A located by the coordinate vector r A on the bar. The lever then exerts an output force F B at the point B located by r B . The rotation of the lever about the fulcrum P is defined by the rotation angle θ in radians. Let the coordinate vector of the point P that defines the fulcrum be r P , and introduce

1475-531: Is put behind the opponent's arm, again grabbing the attacker's wrist and forming a figure-four . By controlling the opponent's body and cranking the arm away from the attacker, pressure is put on the shoulder joint, and depending on the angle, also the elbow joint (in some variations the opponent's arm is brought behind their back, resulting in a finishing position resembling that of the hammerlock outlined below). The name "kimura" started circulating in Brazil after

1534-400: Is reportedly at least 200 years old. The flying armbar or tobi-jūji-gatame (飛び十字固め) is a version of the jūji-gatame that is performed from a stand-up position. Without a gi, it is typically applied when the opponent has a collar tie and arm control. By tightly holding the opponent's neck and arm, the practitioner places one of his shins against the opponent's midsection, and leans up on

1593-440: Is said to have the bottom position. Top positions are usually dominant as fighters can use their weight to their advantage, but depending on the set of rules used, it can have notable exceptions such as the guard . A dominant ground position is usually easier to obtain for the person who initiated the throw or takedown. It may be possible for a fighter in a dominant position to score points or win by pinning their opponent, applying

1652-403: Is sometimes referred to as chicken wing . In recent years, its popularity with North Caucasian wrestlers like Khabib Nurmagomedov has garnered the lock the nickname Dagestani Handcuffs . Lever A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge , or fulcrum . A lever is a rigid body capable of rotating on a point on itself. On the basis of

1711-481: Is the generalized coordinate that defines the configuration of the lever, and the generalized force associated with this coordinate is given by F θ = F A ⋅ ∂ v A ∂ θ ˙ − F B ⋅ ∂ v B ∂ θ ˙ =

1770-481: Is the side mount position. This technique also has numerous variations with their own nomenclature, for instance depending on the rotational direction the arm, the addition of the word "reverse" signifying medial rotation as in reverse keylock or reverse ude-garami , in which case the usage of "keylock" indicates lateral rotation only. Double wristlock/chicken wing ( catch wrestling ), kimura ( Brazilian Jiu-Jitsu ), or reverse keylock are terms used to specify

1829-470: The English word "light". The earliest evidence of the lever mechanism dates back to the ancient Near East c.  5000 BC , when it was first used in a simple balance scale . In ancient Egypt c.  4400 BC , a foot pedal was used for the earliest horizontal frame loom . In Mesopotamia (modern Iraq) c.  3000 BC , the shadouf , a crane-like device that uses a lever mechanism,

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1888-425: The armbar, a combination of an armbar and tomoe nage, which is also used by wrestling, Judo and BJJ . When the attacker stands in front of the opponent, he grabs both of his arms and falls backwards, causing the opponent to lean forward. Then the attacker puts his feet on the opponent's stomach or hips and lifts him up with his feet. While securing one of the opponents arms, the attacker will drop one foot (Same side as

1947-402: The clinch continues, fighters may attempt to strike , takedown or throw an opponent. This may result in a win, or the start of ground grappling. Positioning is the foundation of ground fighting , if one combatant is controlling an opponent from a top position, such as if they are pinning the opponent to the ground, then that combatant is said to have the top position, while their opponent

2006-419: The distance traveled is greater, then the output force is lessened. T 1 = F 1 a , T 2 = F 2 b {\displaystyle {\begin{aligned}T_{1}&=F_{1}a,\quad \\T_{2}&=F_{2}b\!\end{aligned}}} where F 1 is the input force to the lever and F 2 is the output force. The distances

2065-419: The elbow falls at a right angle with the palm facing upwards. Subsequently, the practitioner will thread his opposite hand under the opponent's biceps, reach through and grasp his own wrist. Doing so creates the signature " figure four ", from which one name for this technique was derived. This also gives the practitioner a mechanical advantage over the opponent. To finish the submission the practitioner slides

2124-400: The forces that are perpendicular to the radial segments PA and PB . The principle of virtual work states that at equilibrium the generalized force is zero, that is F θ = a F A − b F B = 0. {\displaystyle F_{\theta }=aF_{A}-bF_{B}=0.\,\!} Thus, the ratio of the output force F B to

2183-421: The ground. (With a gi, it can be performed without needing to hold the neck.) If improperly performed, this technique can allow the opponent to escape, and gain an advantageous position. The flying armbar is considered to be one of the most visually spectacular joint locks, but it is uncommon because of the associated risk of falling into a poor position . The helicopter armbar is a slightly different version of

2242-412: The hinge or bending in the beam. In this case, the power into the lever equals the power out, and the ratio of output to input force is given by the ratio of the distances from the fulcrum to the points of application of these forces. This is known as the law of the lever . The mechanical advantage of a lever can be determined by considering the balance of moments or torque , T , about the fulcrum. If

2301-503: The hips closer to the opponent's elbow and crossing one leg to make a leg triangle around and press down the opponent's humerus/scapula/biceps and triceps/shoulder, could make the hold more secure while additionally allowing the practitioner to deliver strikes to the opponent's head and neck with the non-crossed leg. This technique is used in various grappling martial arts, including but not limited to Brazilian jiu-jitsu , catch wrestling , judo , jujutsu , Sambo , and shoot wrestling , and

2360-426: The input force F A is obtained as M A = F B F A = a b , {\displaystyle MA={\frac {F_{B}}{F_{A}}}={\frac {a}{b}},} which is the mechanical advantage of the lever. This equation shows that if the distance a from the fulcrum to the point A where the input force is applied is greater than the distance b from fulcrum to

2419-419: The input force. On the other hand, if the distance a from the fulcrum to the input force is less than the distance b from the fulcrum to the output force, then the lever reduces the input force. The use of velocity in the static analysis of a lever is an application of the principle of virtual work . A lever is modeled as a rigid bar connected to a ground frame by a hinged joint called a fulcrum. The lever

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2478-441: The knee generally placed close to the opponent's armpit. The advantage of this modification is that the attacking practitioner's hips more closely engage with the defender's shoulders, making the forthcoming armbar submission easier to accomplish. However, the disadvantage of this modification is that the associated risk of injury is increased due to the attacker's increased height above the ground and near-vertical upside-down angle to

2537-442: The lengths a = | r A − r P | , b = | r B − r P | , {\displaystyle a=|\mathbf {r} _{A}-\mathbf {r} _{P}|,\quad b=|\mathbf {r} _{B}-\mathbf {r} _{P}|,} which are the distances from the fulcrum to the input point A and to the output point B , respectively. Now introduce

2596-400: The locations of fulcrum, load and effort, the lever is divided into three types . It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage , which is mechanical advantage gained in the system, equal to the ratio of the output force to the input force. As such, the lever is

2655-414: The next, and thus the applied force is transferred from one lever to the next. Examples of compound levers include scales, nail clippers and piano keys. The malleus , incus and stapes are small bones in the middle ear , connected as compound levers, that transfer sound waves from the eardrum to the oval window of the cochlea . The lever is a movable bar that pivots on a fulcrum attached to

2714-402: The opponent's body and pushing the arm perpendicularly away from the opponent's back, pressure can be put on the opponent's shoulder. It is also possible to put pressure on the elbow joint by bending the leg entangling the arm, and twisting it in a specific manner. In order to secure the opponent and prevent him from rolling out of the lock, the inner arm can be thrown over the opponent's waist as

2773-419: The opponent's wrist to the attacker's chest with the pinky finger on the sternum and the thumb facing up (arm semi- supinated or semi- pronated ), the practitioner can easily extend the opponent's arm and hyperextend the opponent's elbow. The attacker can further increase the pressure on the elbow joint by arching his hips against the elbow. Alternatively, gripping the opponent's wrist and forearm, while pushing

2832-408: The opponent; at the same time, the attacker swings the leg on the same side as the opponent's collar tie over the opponent's head, into the typical jūji-gatame position. A slight modification of this maneuver can also be made. Instead of initiating the move by placing the shin against the opponent's midsection, the lower leg can be directed through the space between the arm and trunk of the opponent with

2891-442: The point B where the output force is applied, then the lever amplifies the input force. If the opposite is true that the distance from the fulcrum to the input point A is less than from the fulcrum to the output point B , then the lever reduces the magnitude of the input force. Grappling position A grappling position refers to the positioning and holds of combatants engaged in grappling . Combatants are said to be in

2950-562: The points A and B are obtained as v A = θ ˙ a e A ⊥ , v B = θ ˙ b e B ⊥ , {\displaystyle \mathbf {v} _{A}={\dot {\theta }}a\mathbf {e} _{A}^{\perp },\quad \mathbf {v} _{B}={\dot {\theta }}b\mathbf {e} _{B}^{\perp },} where e A and e B are unit vectors perpendicular to e A and e B , respectively. The angle θ

3009-411: The pull of gravity) of both a and b change (diminish) as the lever changes to any position away from the horizontal. Levers are classified by the relative positions of the fulcrum, effort and resistance (or load). It is common to call the input force "effort" and the output force "load" or "resistance". This allows the identification of three classes of levers by the relative locations of the fulcrum,

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3068-424: The resistance and the effort: These cases are described by the mnemonic fre 123 where the f fulcrum is between r and e for the 1st class lever, the r resistance is between f and e for the 2nd class lever, and the e effort is between f and r for the 3rd class lever. A compound lever comprises several levers acting in series: the resistance from one lever in a system of levers acts as effort for

3127-430: The secured arm). This will cause the opponent to twist and fall, landing with the secured arm extended by the attacker. The sankaku-gatame (三角固め) or triangle armlock is a jūji-gatame performed from the sankaku position. It is normally used when the shime (strangle) is not working. It is an effective competition technique because the opponent's arm became exposed while defending the sankaku-jime and their attention

3186-780: The stand-up variants are a focus in certain systems such as Chin Na . Armlocks, considered less dangerous techniques in combat sports allowing joint locks, are the most common joint locks used as submission holds . In training, the method of executing an armlock is generally slow and controlled to give the opponent time to submit prior to any infliction of injury. However, in self-defense applications, or when applied improperly or with excessive force, armlocks can cause muscle , tendon and ligament damage, even dislocation , or bone fractures . The jūji-gatame (十字固め, rendered as " Ude-Hishigi-Juji-Gatame "), which translates to "cross pin" or "cross hold down" also sometimes used interchangeably with

3245-463: The term in June 1925 to describe a submission by Jim "Cyclone Thompson" Corrigan over the deputy sheriff of Worley, Idaho , without elaborating on the mechanics. The Wichita Eagle did likewise that April, for Dick Daviscourt's first fall on strongman Henry "Milo" Steinborn. The 1928 National Collegiate Athletic Association rulebook noted, "Attention is called to the fact that if the double wristlock

3304-491: The terms armbar , cross armbar or straight armbar , is a Jujutsu, and thus a Judo, technique also widely used in other grappling martial arts such as Brazilian jiu-jitsu (BJJ). The English word "bar" is used here to signify the opponent's extended arm, while the Japanese word "jūji" (十字) refers to the armbar's visual resemblance to the number 10 as written in kanji , 十. The word jūji is also found in "jūjika" (十字架), meaning

3363-448: The unit vectors e A and e B from the fulcrum to the point A and B , so r A − r P = a e A , r B − r P = b e B . {\displaystyle \mathbf {r} _{A}-\mathbf {r} _{P}=a\mathbf {e} _{A},\quad \mathbf {r} _{B}-\mathbf {r} _{P}=b\mathbf {e} _{B}.} The velocity of

3422-419: The wrist of the opponent toward the lower body, while simultaneously elevating the elbow and forearm, in a motion resembling using a paintbrush, creating opposition to the joints and causing the necessary flexion in the shoulder and elbow to cause significant pain, and damage if the opponent fails to submit. While it is feasible to execute this technique from several different positions, the most commonly utilized

3481-498: Was invented. In ancient Egypt , workmen used the lever to move and uplift obelisks weighing more than 100 tons. This is evident from the recesses in the large blocks and the handling bosses which could not be used for any purpose other than for levers. The earliest remaining writings regarding levers date from the 3rd century BC and were provided, by common belief, by the Greek mathematician Archimedes , who famously stated "Give me

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