Learn about the anatomy of the human hand as well as what hobbies, activities, and careers may damage your hands over time.
The hand is an extremely dexterous and complex part of the body. Each hand contains a total of 27 bones. Combined, this is a total of 54 bones. When you consider that the entire human body only has a total of 206 bones, you can further appreciate the importance of the hands, because the hands contain 25% of all skeletal bones.
The bones of the fingers are long and slender. The bottom of the hand contains several irregularly shaped bones: the scaphoid, capitate, trapezium, trapezoid, lunate, triquetral, hamate, and pisiform. These small, uniquely shaped bones are collectively known as the “carpal” bones. The carpal bones glide and slide against one another providing an incredible range of motion that allows the hand to bend, flex, twist, and move in many different angles and directions.
The thumb joint is amazingly designed to move and bend in such a way that the top of the thumb can touch the tips of all 4 adjoining fingers. This special ability of the thumb to move cross the palm and fingertips is known as “opposability.” It makes the human hand unique among the animal kingdom.
The special arrangement of bones, joints, ligaments, and tendons of the hand enable humans to grasp and manipulate objects with strength and precision. The thumb and tip of the first finger are able to contact one another, creating a pincher grip that can selectively be gentle, exact, firm, or powerful.
The nerve supply to the hand actually begins farther up the body, at the level of the neck. A group of nerve roots exit the spine in the bottom region of the neck, branching outward and twisting downward to form a network known as the brachial (arm) plexus of nerves. These nerves are in some ways similar to electrical wires, conducting signals which convey information to and from the brain. Three of these branches extend down the arm, forming a group of important nerves: the radial nerve, median nerve and ulnar nerve.
Our hands perform thousands of small but important actions during each day that allow us to carry out important activities. The hundreds of ligaments and tendons deep inside the hand must be kept healthy in order to execute these activities efficiently, without clumsiness or dropping objects. Normal daily activities that require the use of our hands include: driving a vehicle, washing dishes, eating a meal, getting dressed, typing on the computer, vacuuming the carpet, writing a note, personal grooming, playing sports, painting, chopping vegetables, using the TV remote, and preparing a cup of tea or coffee.
We often take the use of our hands for granted. However, if we over-use our hands for an extended period of time, without providing enough time for our hands to rest, we risk injuring and damaging them. Certain activities, if done repetitively (over and over for many hours during the week) increase the risk of damage to one or both hands.
Excessive use of the computer keyboard and mouse. If you use the computer for both work and recreation, and are spending many hours a day using a computer mouse, you are at risk for Carpel Tunnel Syndrome as well as sprain / strain type injuries. This risk is compounded if your mouse isn’t comfortable or you are using poor ergonomics while at your workstation.
Carpentry. Repetitive use of carpentry tools for long period can cause damage to the hands, shoulders, and arms. Hammering, sawing, and turning a screwdriver can cause wear-and-tear on the hands.
Gaming (PC and console games). Rapid and prolonged clicking of the mouse buttons and computer keys can cause injury to the small tendons of the hands. Holding the wrists at an uncomfortable angle, or using “sloppy” posture after hours of gaming can put pressure on the important nerves to the hands.
Gardening and yard work. Digging in the soil, pulling weeds, trimming hedges, pruning plants, raking leaves, moving wheelbarrows, hoisting bags of fertilizer, cutting tree limbs, and lifting potted plants – all these activities can place a lot of mileage on the hands.
Tablet / Mobile devices. Extended use of an electronic tablet, phone, or other mobile device can cause inflammation and damage to the joints, tendons, and ligaments of the hands. In addition, when a person’s head is angled too far forward while looking at the mobile device, the important nerves that extend from the neck to the hand can become irritated. This can cause complications with the hands, as well as slow the healing process.
A person uses their hands while working in every career. However, certain jobs require extended use of the hands with an increased risk of hand injury. Activities where the hands must work continually, with the wrist at an unusual angle tend to cause the most problems over time.
Here are examples of 10 careers that increase the risk of hand injury due to over-using the hands:
Electrician. Electricians are often forced to work in unusual positions that put strain on the shoulders, arms, and wrists.
Dentist/Dental Hygienist. These individuals usually work with their neck rotated to the same side for many hours during the day. This can irritate the nerves which extend from the neck to the arms and hands.
Medical Biller/Coder. Members of this profession must pay close attention to having correct ergonomics due to extensive time involved in transferring data from files to their workstation. If they reach too far for their computer mouse or type with their wrist at an uncomfortable angle, they risk damaging their hands.
Hair Stylist / Barber. Hair care professionals are more likely to injure their hands and arms if their client’s chair does not raise or lower the correct amount. This forces the stylist to reach up or down and engage in poor biomechanics.
Sign Language Interpreter. Members of this profession are most likely to injure themselves if their posture isn’t relaxed while signing. They also risk damaging their hands if they don’t give themselves sufficient time to rest their hands and arms between sessions.
Mechanic (auto / machinery). Mechanics often work in uncomfortable positions, sometimes on their back or leaning far forward. They require tremendous hand strength to add and remove parts from vehicles.
Musician. Musicians should be mindful of their posture while playing. Professional musicians should stretch and prepare their shoulders, neck, arms, and hands before performances.
Lawn care. Certain activities such as trimming, hedging, and weeding should not all be done on the same day. These and other activities that can irritate the hands should be alternated with mower riding actives to break up the day and give the hands a rest.
Artist. Some artistic mediums such as working with metal, or clay require more hand strength. Graphic artists require their work station / electronic stylus / keypad setup to have correct ergonomics. Artists who utilize paints and brushes should give themselves enough of a break between painting sessions. Tattoo artists need to keep their hands and shoulders relaxed, as well as making sure they don’t remain in the same position for too long.
HVAC. Residential, commercial, and industrial HVAC technicians work in positions that can put strain on the hands as well as the rest of the skeleton. They need precision as well as strength in their fingers to perform daily tasks.
Types of injuries to the hands include: wrist strains, trigger finger, Carpal Tunnel Syndrome, “Texter’s thumb” (De Quervain’s Tenosynovitis), and inflamed tendons. Care should be taken to protect the hands while at work and participating in daily activities. If you are spending many hours a week engaging in activities that over-work the hands, consider seeing a chiropractor who has experience with manipulating the bones of the hand and wrist. This will keep the bones of the hand in a more correct position. Chiropractic treatment can also reduce inflammation and improve fine motor skills.