Videotape Guidelines and Analysis

Video Guidelines for Ergonomic Evaluations

Obtaining good video documentation for ergonomic evaluations can be difficult — as the tasks are often performed in inaccessible areas with poor lighting conditions and a lot of extraneous movement taking place. This guide presents suggestions for capturing effective video documentation of potential ergonomic hazards.

Preparation

Use the OSHA Form 200 logs and 101s (and after January 1, 2002 the OSHA Form 300 series), complaint information, and interviews to help prioritize areas for taping. It is desirable to have at least a two-person team when performing an evaluation. One person can operate the video camera while the other can record task and employee information.

The equipment needed for an ergonomic inspection will generally include:

• Video camera with extra tapes and charged batteries,

• Tape measure,

• Small notebook,

• Fanny pack,

• Small scale (Chattillon or fish scale that can measure pull forces),

• Bungee cord or small piece of rope, and

• Questionnaires for employee interviews concerning ergonomic factors.

Other useful items may include:

• Stop watch,

• Lens cleaning paper,

• Extra batteries for internal clock, and

• Skylight UV filter. This is a must in a dirty environment if you do not have a protective case.

The following are general suggestions on camera usage which, if reviewed prior to going on-site, will provide the best video documentation for the analyst and ensure that all pertinent information is obtained and documented.

• Become familiar with the camera and read the operators manual. Shoot some test footage so you are familiar with all the functions of the camera.

• Always activate the date and time mechanism on the camera so that this information is displayed on the video during the entire taping series. This will provide additional reference points with which to correlate written information with the videotape footage. Be aware of the position of the date and time printout on the video footage to make sure that it is not superimposed over the top of important features of the video documentation.

• For operations with extraneous movement it may be necessary to use the manual focus to avoid the camera refocusing on irrelevant moving objects. Determine where the focus point is for the camera you are using. It may not be in the center of the viewfinder. To make this determination place the camera on auto focus and try to focus on a small item such as a hanging pendant that has nothing else in the same plane. Hang the item from a doorway and try to focus by moving the item back and forth in the field of the viewfinder. You have found the focus point when the camera focuses on the item.

• If the camera has a high speed shutter, turn it off and use the auto shutter. high speed requires too much light for most industrial tasks. If you are taping a worker with dark clothes against a light background (such as a window, or a white wall), activate the "back lit" capability on the camera.

• Practice visual slating of information. This should be done by filming a piece of paper with information clearly written on it just prior to or directly after videotaping the task. Use a marker or dark pen that can be clearly seen. The macro-zoom on your camera will permit use of a small notebook or journal to be used as a slate. A small notebook is easy to carry and any pertinent notes can be recorded on the slate sheet for easy correlation and future reference. Macro-zoom is also helpful for documentation of small informational areas such as labels.

• If visual slating is absolutely not possible, cover the lens with your hand and record the information verbally before the actual job taping begins. Be aware that you will need to speak directly into the camera microphone to be clearly understood. Use of an external microphone can be helpful in audio slating.

• Hold the camera as still as possible or use a tripod if available. Don't walk with the camera unless absolutely necessary to record the task. When you change location, move slowly and minimize camera movement. Use the zoom instead of walking whenever possible. Use the manual focus whenever there is extraneous movement in the frame of action to ensure the focus will be on the items of interest.

Videotaping Tasks

The following items outline the procedures used for obtaining useful video documentation.

• If possible tape the operation in the order of production. Do the beginning of the production process first and proceed through all tasks of interest.

• Visually slate at least the name of the task just prior to or directly after videotaping the task.

• Tape 5–10 minutes for all jobs including approximately 10 cycles. A cycle is considered to be a set of repeated motions during which one part or assembly is processed. Jobs that have relatively long cycle times in excess of 30–60 seconds may require fewer than 10 cycles if all aspects of the job are recorded at least 3–4 times.

• Begin each task with a whole-body view of the worker from the side including the chair and/or the floor. Hold this view for 2–3 cycles and then zoom the camera in for a closer view of the area of principal interest. Tape from a variety of angles to allow a determination of wrist deviation, arm postures, back angles, etc. Tape from both sides and the front if possible. The total footage may be distributed between these different angles.

• Videotape the operation from a distance to give perspective to the analyst about workstation layout.

• Find an entity of known dimension in the frame of the picture and measure it for reference purposes. The employee's forearm from the wrist to the elbow is a convenient landmark since it is in most frames and is measurable on the television screen. If possible place a piece of contrasting tape on the reference points to provide a more distinct and identifiable location point. Record the reference dimensions either by visually slating the information or verbally recording the data. If using a ruler or tape measure as your reference point, ensure that the increments are clearly visible.

• Obtain video footage of tools or machinery that are used on the job. Videotape labels from hand tools, machinery, weight from boxes, etc.

Additionally, the following information should be visually slated at the beginning of each individual task or recorded in a written supplemental factors checklist.

• The name of the task and employee.

• Anthropometry (height) of the employee.

• Ambient conditions when working in extreme areas (freezers, furnaces, etc.).

• Clothing and PPE (materials, etc.).

• The period of time in which the task is performed including work-rest schedules.

• The nature of injuries as determined from the 200's, 101's, 300's, or interviews.

• Weight and dimension of loads lifted.

• Dimensions of the work items seen in the shot (i.e., pallets, tables, shelving units, etc.).

• Vertical distance between origin and destination of lift. Horizontal distance the load is held from the body at the beginning and end of the lift. These distances can be estimated directly from the video documentation if measuring will significantly interfere with the operation. To do this there must be a clear view of the entire body and the work space, preferably in profile. Provide dimensional information on as many work items seen in the footage as possible.

• Distance loads must be carried.

• Production data to aid in determining if the video segment is representative of normal activity.

• Conditions that might affect grip or traction (ie., sand on the floor, ice on boxes being lifted, etc.).