Handle

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A modern claw hammer with rubber-coated handle Claw-hammer.jpg
A modern claw hammer with rubber-coated handle
Knife handle Morakniv Basic 511 Carbon Steel.jpg
Knife handle

A handle is a part of, or attachment to, an object that allows it to be grasped and manipulated by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tradition. Handles for tools are an important part of their function, enabling the user to exploit the tools to maximum effect. Package handles allow for convenient carrying of packages.

Contents

General design criteria

Flat-nose pliers with thermoplastic handles Tool-pliers.jpg
Flat-nose pliers with thermoplastic handles
Spade with handle Spade with adjustable handle - Ivan Topalovic Nursery Lipolist.jpg
Spade with handle

The three nearly universal requirements of are:

  1. Sufficient strength to support the object, or to otherwise transmit the force involved in the task the handle serves.
  2. Sufficient length to permit the hand or hands gripping it to comfortably exert the force. [1]
  3. Sufficiently small circumference to permit the hand or hands to surround it far enough to grip it as solidly as needed to exert that force. [2]

Specific needs

Other requirements may apply to specific handles:

Pull handles

Many drawers use pull handles. Drawer handle.jpg
Many drawers use pull handles.

One major category of handles are pull handles, where one or more hands grip the handle or handles, and exert force to shorten the distance between the hands and their corresponding shoulders. The three criteria stated above are universal for pull handles.

Many pull handles are for lifting, mostly on objects to be carried.

Horizontal pull handles are widespread, including drawer pulls, handles on latchless doors and the outside of car doors. The inside controls for opening car doors from inside are usually pull handles, although their function of permitting the door to be pushed open is accomplished by an internal unlatching linkage.

Pull handles are also a frequent host of common door handle bacteria such as e-coli, fungal or other viral infections. [4]

Two kinds of pull handles may involve motion in addition to the hand-focused motions described:

Twist handles

Many doors use twist handles. Door handle designed by Jasper Morrison.jpg
Many doors use twist handles.

Another category of hand-operated device requires grasping (but not pulling) and rotating the hand and either the lower arm or the whole arm, about their axis. When the grip required is a fist grip, as with a door handle that has an arm rather than a knob to twist, the term "handle" unambiguously applies. Another clear case is a rarer device seen on mechanically complicated doors like those of airliners, where (instead of the whole hand moving down as it also rotates, on the door handles just described) the axis of rotation is between the thumb and the outermost fingers, so the thumb moves up if the outer fingers move down.

Handles for wide-range motion

The handles of bicycle grips, club-style weapons, shovels and spades, axes, hammers, mallets and hatchets, baseball bats, rackets, golf clubs and croquet mallets involve a greater range of ergonomic issues.

See also

Related Research Articles

<span class="mw-page-title-main">Hammer</span> Tool consisting of a shaft with a weighted head attached at a right angle

A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal, or to crush rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, warfare, and percussive musicianship.

<span class="mw-page-title-main">Pipette</span> Liquid-transferring laboratory tool

A pipette is a type of laboratory tool commonly used in chemistry and biology to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes. Many pipette types work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid. Measurement accuracy varies greatly depending on the instrument.

<span class="mw-page-title-main">Pliers</span> Hand tool

Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other side. This arrangement creates a mechanical advantage, allowing the force of the grip strength to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers.

A crochet hook is an implement used to make loops in thread or yarn and to interlock them into crochet stitches. It is a round shaft pointed on one end, with a lateral groove behind it. The point eases the insertion of the hook through the material being crocheted and the groove makes it possible to pull a loop back through the material. The shaft is then divided into a working area that determines the hook's nominal diameter and ensures the uniform sizing of the loops formed on it, and a handle.

<span class="mw-page-title-main">Tweezers</span> Tool for grabbing small objects

Tweezers are small hand tools used for grasping objects too small to be easily handled with the human fingers. Tweezers are thumb-driven forceps most likely derived from tongs used to grab or hold hot objects since the dawn of recorded history. In a scientific or medical context, they are normally referred to as just "forceps", a name that is used together with other grasping surgical instruments that resemble pliers, pincers and scissors-like clamps.

<span class="mw-page-title-main">Yangqin</span> Musical instrument

The trapezoidal yangqin is a Chinese hammered dulcimer, likely derived from the Iranian santur or the European dulcimer. It used to be written with the characters , but over time the first character changed to , which means "acclaimed". It is also spelled yang ch'in. Hammered dulcimers of various types are now very popular not only in China, but also Eastern Europe, the Middle East, India, Iran, and Pakistan. The instruments are also sometimes known by the names "santoor" and "cymbalom". This instrument had an influence on the Thai classical instrument, known as Khim (ขิม).

<span class="mw-page-title-main">Smith & Wesson Model 22A</span> Semi-automatic pistol

The Smith & Wesson Model 22A is a semi-automatic pistol that was manufactured in Houlton, Maine. The 22A is a full-size pistol with an aluminum alloy frame. The steel barrel has an integrated Weaver style rail.

A gunstock or often simply stock, the back portion of which is also known as a shoulder stock, a buttstock, or simply a butt, is a part of a long gun that provides structural support, to which the barrel, action, and firing mechanism are attached. The stock also provides a means for the shooter to firmly brace the gun and easily aim with stability by being held against the user's shoulder when shooting the gun, and helps to counter muzzle rise by transmitting recoil straight into the shooter's body.

<span class="mw-page-title-main">Grip strength</span> Force applied by the hand to hold

Grip strength is the force applied by the hand to pull on or suspend from objects and is a specific part of hand strength. Optimum-sized objects permit the hand to wrap around a cylindrical shape with a diameter from one to three inches. Stair rails are an example of where shape and diameter are critical for proper grip in case of a fall. Other grip strengths that have been studied are the hammer and other hand tools. In applications of grip strength, the wrist must be in a neutral position to avoid developing cumulative trauma disorders.

<span class="mw-page-title-main">Pistol grip</span> Handle for a firearm or other tool

On a firearm or other tools, a pistol grip is a distinctly protruded handle underneath the main mechanism, to be held by the user's hand at a more vertical angle, similar to how one would hold a conventional pistol.

<span class="mw-page-title-main">Burton grip</span> Type of four-mallet technique

The Burton grip is a method of holding two mallets in each hand in order to play a mallet percussion instrument, such as a marimba or a vibraphone, using four mallets at once. It was developed by jazz vibraphonist Gary Burton around the 1960s.

<span class="mw-page-title-main">Lineman's pliers</span>

Lineman's pliers, Kleins, linesman pliers, side cutting linesman pliers and combination pliers are a type of pliers used by lineworkers, electricians, and other tradespeople primarily for gripping, twisting, bending and cutting wire, cable, and small metalwork components. They owe their effectiveness to their plier design, which multiplies force through leverage.

<span class="mw-page-title-main">Hook grip</span> Method of gripping a barbell

Hook grip is a method of gripping a barbell used in many strength-related sports such as Olympic weightlifting, Crossfit, and powerlifting by overlapping the index and middle finger over the thumb. This method of gripping the bar provides a secure bar grip while performing pulling motion with the barbell such as the clean and jerk, snatch, and deadlift. To perform a hook grip one must first wrap their thumb around the bar placing it parallel to the barbell and then wrap their index, and middle finger around the outside of the thumb. The pinky and ring finger typically ends up resting on the barbell. It is important to actively hooking on to the thumb with the index and middle finger while performing Hook grip compared to providing direct pressure on to the thumb.

<span class="mw-page-title-main">Manual handling of loads</span> Use of the human body to lift, lower, carry or transfer loads

Manual handling of loads (MHL) or manual material handling (MMH) involves the use of the human body to lift, lower, carry or transfer loads. The average person is exposed to manual lifting of loads in the work place, in recreational atmospheres, and even in the home. To properly protect one from injuring themselves, it can help to understand general body mechanics.

<i>Hojo undō</i> Style of martial arts training

Hojo undō (補助運動) is a Japanese language term, translated as "supplementary exercises", that refers to conditioning exercises used in martial arts, especially in karate. Hojo undō training was designed to develop ambidextrous physical strength, stamina, muscle coordination, speed, and posture. This style of training uses simple, traditional devices made from wood and stone.

An end effector is the device at the end of a robotic arm, designed to interact with the environment. The exact nature of this device depends on the application of the robot.

<span class="mw-page-title-main">Grip (percussion)</span> Percussion playing technique

In percussion, grip refers to the manner in which the player holds the sticks or mallets, whether drum sticks or other mallets.

<span class="mw-page-title-main">Ergonomic hazard</span> Physical conditions that may pose a risk of injury

Ergonomic hazards are physical conditions that may pose a risk of injury to the musculoskeletal system due to poor ergonomics. These hazards include awkward or static postures, high forces, repetitive motion, or short intervals between activities. The risk of injury is often magnified when multiple factors are present.

The Fulcrum grip is a four-mallet grip for vibraphone and marimba developed by vibraphonist and educator Ed Saindon. The aim of the grip is to use varying fulcrum positions and finger technique to achieve the control, speed, and power of a two-mallet grip while being able to use all four mallets.

Manual material handling (MMH) work contributes to a large percentage of the over half a million cases of musculoskeletal disorders reported annually in the United States. Musculoskeletal disorders often involve strains and sprains to the lower back, shoulders, and upper limbs. They can result in protracted pain, disability, medical treatment, and financial stress for those afflicted with them, and employers often fi nd themselves paying the bill, either directly or through workers’ compensation insurance, at the same time they must cope with the loss of the full capacity of their workers.

References

  1. Schoenmarklin, R W (1989), "Effects of handle angle and work orientation on hammering: II. Muscle fatigue and subjective ratings of body discomfort" (PDF), Human Factors, 31 (4): 413–420, retrieved 24 June 2023
  2. Liao, Kun-Hsi (2016), "Optimal Handle Grip Span for Maximum Hand Grip Strength and Accurate Grip Control Strength Exertion according to Individual Hand Size" (PDF), Osteoporosis & Physical Activity, 4 (2), retrieved 24 June 2023
  3. Wang, Mao-Jiun J. (Winter 2000). "The Effect of Handle Angle on MAWL, Wrist Posture, RPE, and Heart Rate". Human Factors. 42 (4): 553–565. CiteSeerX   10.1.1.1000.7796 . doi:10.1518/001872000779698079. PMID   11324850. S2CID   7243355.
  4. Door Handles Can Spread Germs retrieved November 2016