Which of the following physical fitness test assesses that endurance of the abdominal muscles?

Many physical fitness tests have been designed to evaluate the physical fitness of schoolchildren, armed services personnel, athletic teams, and countless others engaged in health and fitness programs.

In spite of long-standing and widespread use, three tests in particular need to be re-evaluated:

1. Bent knee sit ups test.
2. Push ups test.
3. Sit and reach test.

The usefulness of these tests depends on their accuracy and their ability to detect deficiencies. Unfortunately, Physical Fitness Tests have become an evaluation of the performance rather than a measure of the physical fitness of the performer. Emphasis is on excesses speed of performance, number of repetitions, and extent of stretching rather than on quality and specificity of movement.

Bent knee sit ups test

The Bent knee sit ups test requires that a person perform as many sit-ups as possible in a period of 60 seconds.

The stated purpose of the test is to measure endurance and strength of the abdominal muscles. The test does not fulfill that purpose, however. Instead, it measures strength and endurance of the hip flexor muscles, aided in their performance by stabilization of the feet.

The sit-up movement requires flexion of the hip joints, and this movement can be performed only by hip flexors. Abdominal muscles do not cross the hip joint, so they cannot assist in the hip flexion movement. Abdominal muscles flex the spine (curl the trunk), and to test the strength of these muscles, the trunk must be curled. If these muscles can hold the trunk curled as the movement of hip flexion is performed, this indicates good upper abdominal muscle strength.

The problem with using the sit-up movement as a test or an exercise lies in the failure to differentiate between a “curled trunk sit-up” and an “arched back sit-up.” The former involves strong contraction of the abdominal muscles to hold the trunk curled; the latter puts a stretch on the abdominal muscles and a strain on the low back. This strain may be felt by both children and adults when they are required to perform as many sit-ups as possible in the time allotted.

Many will start the sit-up with the trunk curled. The endurance of the abdominal muscles will not be sufficient to maintain the curl, however, and as the test progresses, the back will arch increasingly. Some will not have the strength even to curl the trunk initially, and the test will be done with the back arched for the entire 60 seconds.

The problem is that those with weak abdominal muscles can pass this so-called “abdominal muscle test” with a high score. The test, as advocated, requires speed of performance. For accurate testing of abdominal muscle strength, however, the test must be done slowly, making sure that the trunk curls before hip flexion starts and that the curl is maintained both when hip flexion starts and while moving to the sitting position.

To have validity, the test should require that credit be given only for the number of sit-ups that can be performed with the trunk curled. Currently, the test has no such requirement. Furthermore, the test cannot be done rapidly if the position of the trunk is to be observed closely.

The people most in danger of being adversely affected by repeated sit-ups with the knees bent are children and youths because they start with more flexibility than adults. Those adults who have low back pain associated with excessive low back flexibility also may be adversely affected by this exercise.

An interesting phenomenon in some subjects who have done a great number of Bent knee sit ups is that they show excessive flexion in sitting or in forward bending but a lordosis in standing.

It is unfortunate that the ability to do a certain number of sit-ups, regardless of how they are performed, is used as a measure of physical fitness.

Along with pushups, these two exercises probably are stressed more than any others in fitness programs. Done to excess, however, these exercises tend to increase—or even produce—postural faults.

Push Ups Test

When a push-up is performed properly, the scapulae abduct as the trunk is pushed upward. The scapulae move forward to a position that is comparable to that of reaching the arms directly forward.

When the serratus anterior muscle is weak, the push-up movement still can be performed, but the scapulae do not move into the abducted position as in a properly performed push-up.

If the primary purpose of the push-ups is to test strength and endurance of the arm muscles, it accomplishes that purpose, but in the presence of serratus weakness, it does so at the expense of the serratus muscle.

Evidence for this is seen in the winging of the scapulae and in the inability to complete the range of
scapular motion in the direction of abduction.

When push-ups are done at the expense of the serratus muscle, the activity can no longer be considered an index for the physical fitness of the person being tested.

Sit and Reach Test

Sitting with knees extended, this test is done by reaching forward to touch fingertips to toes. For young children and most adults, touching the toes in this position may be considered a normal accomplishment. Reaching beyond the toes usually denotes excessive flexibility of the back, excessive length of the hamstrings, or both.

The stated purpose of the sit and reach test is to evaluate the flexibility of the low back and hamstrings.

Scoring is based on how many inches beyond the toes the individual can reach. Ostensibly, the distance beyond equates with good, better, or best flexibility of the back and hamstrings, with emphasis on “the more, the better.”

This test fails to address important variables that affect test results. Variations in “normal” occur according to age group, and limitations result from imbalances between the length of back and hamstring muscles.

This inability to touch toes, much less to reach beyond them, is normal for many youths between the ages of 10 and 14 years. These children are at a stage of growth when the legs are long in relation to the trunk,
and they should not be forced to touch their toes.

Limited back flexibility can go undetected if the hamstrings are stretched. Individuals with this imbalance may “pass” the test, whereas many children with normal flexibility for their age will “fail.” It would be more accurate to say that the test has failed these children than to say that these children have failed the test.

In addition to being told that they have “failed,” many young people are then given exercises to increase flexibility of the spine and/or stretch the hamstrings when such exercises are unnecessary or even contraindicated.

Adults will demonstrate numerous variations in length of the hamstrings and back muscles. Like adolescents, those adults whose legs are long in relation to the trunk may have normal flexibility of the back and hamstrings yet be unable to touch their toes.

The extensive use of physical fitness tests and the importance placed on their results make it imperative that these tests be carefully scrutinized.

In one study the sit and reach tests had a moderate mean criterion-related validity for estimating hamstring extensibility (rp = 0.46-0.67), but they had a low mean for estimating lumbar extensibility (rp = 0.16-0.35). 

References

1. Mayorga-Vega D, Merino-Marban R, Viciana J. Criterion-related validity of sit-and-reach tests for estimating hamstring and lumbar extensibility: A meta-analysis. Journal of sports science & medicine. 2014 Jan;13(1):1. Link
2. Muscles: Testing and Function with Posture and Pain. Book by F. P. Kendall, 5th Edition.

Which physical fitness test measures your abdominal strength and endurance?

How do you test abdominal muscular endurance?