INDH 5335-Ergonomic Methods & Analysis Techniques Masonry & Stonework JOSE K XAVIER Instructor: Dr. Magdy Akladios

ERGONOMIC EXPOSURE Masonry construction is one of the specialty trades with high risk of work related injuries. In the masonry trade, conditions that carry a high risk of work-related musculoskeletal injuries were identified through site observations and ergonomic analysis. The ergonomic analysis of work activities among bricklayers and mason tenders focused on working in awkward postures, lifting, and wrist and arm movements in trowelling.

POTENTIAL SYNDROMES Carpal Tunnel Syndrome Problem of the nerve in the hand and wrist, caused by repeated bending of the wrist, holding tools or materials tightly, constantly pressing the wrist against a hard object.  Raynaud’s Syndrome or White Finger Disease Problem of the nerves and blood vessels in the hands often caused by use of vibrating hand tools.

Thoracic Outlet Syndrome Problem caused by reduced blood flow in the shoulder and arm caused by overhead work or carrying heavy items in the hands with the arms straight down. Tendinitis An inflammation and soreness in tendons, caused by repeated movement of a joint. 

BODY PARTS AFFECTED Upper arm Back Shoulder Forearm/hand muscles Wrist Upper Limb Ear

CAUSES OF THE SYNDROME Heavy Work Manual Materials Handling (MMH) Pushing Twisting Frequent Lifting (over 25 pounds) Stooped Postures Awkward Postures (i.e., twisting while stooped) Prolonged Overhead Work Recoil Impact Vibrations

RISK FACTORS Workers often perform more than 1000 forward bending tasks per shift and are therefore at risk of developing low-back disorders. Workers who have to lay brick and block above shoulder height increase their risk of developing shoulder, arm, and wrist problems.

Workers generally use large trowels (12-inch) that enable them to lay more mortar per application but also increase the risk of elbow and wrist injuries. Many workers wear gloves when lifting and placing block. Gloves actually reduce grip strength. Mortarboards are typically positioned at or below knee level. This forces workers to bend forward repetitively -- a contributing factor to low-back disorders.

Masonry workers are exposed to environmental factors such as wind and excessive heat and cold. Walking or working on uneven, muddy, or icy surfaces exposes bricklayers and mason tenders to the risk of slips, trips, and falls. Bricklayers often work in restricted spaces where their freedom of movement is limited. As a result they must adopt awkward, twisting movements when lifting and laying brick and block. This increases the risk of musculoskeletal injury.

The stress of maintaining the expected production rate (about 200 blocks or 600 bricks per day) can lead to muscle tension and greater likelihood of injury. Working with stone can lead to upper limb disorders. The most common cause is a vibrating hand tool. These disorders can affect a stonemason’s fingers, arms, shoulders and neck. 

PREVENTION METHODS Develop information and training on trade- specific ergonomic practices, including work pacing. Identify best practices to reduce injuries and increase efficiency for instance, mast-climbing work platforms. Implement a pre-job exercise program and improve work/rest cycles to reduce fatigue and injury. Plan and organize sites to facilitate access, reduce unnecessary materials handling, and avoid work in constricted spaces that force workers into awkward postures and twisting movements.

Use height-adjustable mortarboards to reduce forward bending Use height-adjustable mortarboards to reduce forward bending. Similarly, keep platforms for stocking brick and block no lower than knee-height. Educate workers regarding the importance of using a trowel suited to their individual size and strength. Work with manufacturers to develop more ergonomically favorable bricks and blocks.

FIXES Brick and block carts, large tires Heavy duty, 29" wide, brick and block carts with large tires, capable of moving over rough ground and scaffolding. May reduce lifting, and gripping or pinching of brick and block while stocking. May also reduce carrying. Bucket handle grip, add-on Grip handle fits over existing handle to provide a more comfortable, larger diameter grip. May reduce forceful gripping and pressure from sharp edges.

Concrete bucket, loader attachment Concrete placement bucket attaches to a skid-steer loader and allows small pours in areas where concrete trucks can not reach. Holds half a cubic yard. Reduces the need to use wheelbarrows and shoveling to move concrete. May reduce heavy lifting, forceful gripping and repetitive motions.

Hand truck, dual direction Two-wheeled hand truck with pivoting wheels converts from standard use to use as a panel cart to move large, flat items such as doors, windows, plywood, tables, etc.. This may reduce the need for heavy, awkward lifting and carrying when moving and delivering these materials.

Thank you..