Thursday, February 19, 2015

Work Hardening

One of the challenges of bringing a disabled person back into normal jobs is the need to "work harden" them.

Most factory jobs establish the maximum work-content based on some demographic.   There are at least four axis that must be considered:

Plowing was traditionally done by younger men.  Breaking 10 acres of new ground in the spring meant wrestling a breaking plow behind a team of horses after a sedentary winter.  Plowing 10 acres meant the plowman had to walk approximately 40 MILES.  Photo from HERE.


Our maximum ability diminishes with age.  Our ability to gain condition slows.  Our ability to heal from stresses also slows.


In aggregate, men have more physical strength than women.  The difference in strength is particularly pronounced in the upper body.


Some people have larger frames than others.  A woman who is 5th percentile (short) for stature must be in a higher state of condition than a woman who is 90th percentile for stature to lift the same amount of weight.

Initial level of conditioning:

A person who is in moderate condition will gain additional capability more quickly than a person who is already at very high levels of condition.  For example:  A person who can bench-press 80 pounds can be conditioned to bench-press 160 pounds (twice the baseline amount) in a reasonable amount of time.  A person who can bench-press 400 pounds will likely never be able to bench-press 800 pounds regardless of how long and how hard they train.

People of moderate condition are also likely to gain capability more quickly than an absolute couch potato who does not have enough stamina to perform a full workout.

From Cooper's Age/Gender Normed physical fitness standards.  Repetitions of situps chosen as the data charted.  Note:  Situps are body-weight exercises and are not to be confused with "absolute" strength metrics like max bench press.  80th Percentile 25 year old woman arbitrarily assigned value of 100% and other capabilities normalized to that level.

Consider a factory job that is designed to be just within the capabilities of the 50th percentile 25 year old woman.  The thought process might be that the half that are not capable of walking up to the job and performing will gain stamina during the training process.  Even the 20th percentile young woman is capable of performing 67% of the required number of repetitions the day they start work.  They quickly gain capability (i.e. work harden) as they follow their training program.

This method worked pretty well when factories only hired young people and there was little job mobility.  It also worked well when society accepted age discrimination and looked the other way when older workers were fired.  It also worked pretty well when seniority systems allowed older workers (presumably with more seniority) to percolate into less physically demanding jobs.

Today factories are compelled to hire a mix of demographics to avoid the stigma of discrimination.  Society no longer tolerates age discrimination...many older people are working because they must work.  And the nature of work in the factory changed;  there are no "easy" jobs, most work is done by teams that rotate through a variety of jobs to balance out the ergonomic stresses on the body.  Competitive pressures do not allow factories to lard their ranks with large numbers of "light" jobs.

The prospect of success for new, or returning, employees over age thirty appears increasingly dismal.  But is it?

Same chart as above but the biological potential are shown as the purple bar.  Cooper's 25 year old, 95th percentile woman and the degradation rate described in the next paragraph of text used to define biological potential. 

Trainers who specialize in "older" athletes claim that the biological limits to physical strength and stamina remain fairly constant until age forty.  Then, from age forty until age seventy the biological limits diminish approximately 10% per year.  That is shown on the chart with the purple columns.  (To the statistically literate:  I know that 95th percentileis not the ultimate limit of human potential but it is the most readily available, defensible number that goes with the situp data.)

What changed were our societal norms regarding conditioning.  We gain body fat as we age.  We become much more sedentary.  We think we look undignified and pretentious when we stretch.  We become absorbed in supporting our kids...we sit on the sidelines and watch them exercise.  We let ourselves go.

The other thing that changed is the speed with which our bodies heal.  Younger people can be very sloppy in their training and still gain strength and stamina without hurting themselves.  Conditioning is a process of repeatedly stressing (actually hurting) our bodies and then allowing a recovery period for our bodies to adapt to that stress.  Us older folks require longer recovery periods and less aggressive ramping-up of stresses.

Older employees can "get there" but our starting line is much farther back from the finish line than for younger employees and we simply cannot ramp up capability as quickly as younger employees.

The "work hardening" program that is optimum for the traditional, younger worker pushes too hard and ramps up too fast for the older worker.  It puts them at risk of injures. 

The dilemma

A nearly ideal ramp-up for a new or returning older worker would be to work part-time for an extended period.  One example would be to work Monday-and-Friday for several weeks.  That would allow them a three day recovery period and a two day recovery period every week.  A Monday-and-Friday work schedule has logistical advantages as these days are typically the most highly sought after vacation days.

The next logical step in the progression would be to work Monday-Wednesday-Friday.

It is my impression that very few Unions will negotiate this kind of stepped return-to-work.  Their contention is that any employee cleared by Medical should receive 40 hours of pay a week and finding suitable work is Management's problem.

Even in the absences of activist contractual language, many Human Relations departments do not seem to want the additional complexity of non-traditional work schedules.

Personal Responsibility

There is a solution.  It is called personal responsibility.  Even in her mid-sixties a woman who is 80th percentile only need double her capability to meet the job requirements.  By contrast, the 20th percentile woman in her mid-sixties must improve her capability by a factor of TEN to match the 50th percentile 25 year old.  The process of increasing physical capability by a factor of ten is long, difficult and fraught with the possibility of injury.

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