Kraus-Weber Abdominal Strength Test 2 Calculator

About the Kraus-Weber Abdominal Strength Test 2

This abdominal test assesses the strength of the abdominal muscles with minimizing the use of the psoas muscles. Participants perform one situp with legs raised, knees bent. This test is part of the Kraus-Weber fitness test protocols, a series of six medical fitness test measures the strength and flexibility of key postural (core) muscles.

Test purpose: To assess the strength of the abdominal muscles while minimizing psoas involvement.

Equipment required: Flat surface (mat or floor)

Pre-test: Explain the test procedures to the subject. Perform screening of health risks and obtain informed consent. Prepare forms and record basic information such as age, height, body weight, gender, test conditions. Ensure that the participants are adequately warmed-up. See more details of pre-test procedures.

Procedure: The lying position for this test is the same as the first K-W test — the subject lies down in a supine position flat on his back and hands behind his neck, except that this time the knees are bent. The examiner holds the feet to keep them on the ground. The subject is required to perform one sit-up. If he is able to perform a full sit-up, he passes this test. If he is unable to raise his shoulders from the table or ground, the score is zero.

Scoring: This test is graded on a pass-fail basis. The Kraus-Weber test comprises 6 exercises - being unable to perform even one of the six exercises results in failing the test.

Advantages: This is a very simple test to conduct, which can be performed quickly with minimal equipment.

Comments: The difference between this test and the first Kraus-Weber Abdominal Strength Test is that in this case the knees are held in a bent position, which minimizes the involvement of the psoas muscles and isolates the abdominal muscles more effectively.

Understanding the Kraus-Weber Fitness Test

The Kraus-Weber Minimum Test, developed by Dr. Hans Kraus and Dr. Sonja Weber at New York Presbyterian Hospital in the 1950s, represents a landmark assessment in sports medicine and fitness testing. According to research by Robert J. Wood, PhD in Exercise Physiology from the University of Western Australia and founder of Topend Sports, this six-item medical fitness test measures minimum muscular fitness - the baseline strength and flexibility required for postural health and athletic function.

The test gained national attention when Bonnie Prudden's research revealed that 56.6% of American children failed the test compared to only 8% of European children. This alarming disparity led to President Eisenhower establishing the President's Council on Physical Fitness and Sports in 1956, fundamentally changing physical education in America.

Why Test 2 Is Critical for Athletes

Test 2 - the bent-knee sit-up - specifically isolates the abdominal muscles by reducing psoas contribution. For athletes, strong abdominal muscles are essential for:

• Core stabilization: Maintains spinal alignment during explosive movements
• Force transfer: Connects upper and lower body power in throwing, jumping, kicking
• Injury prevention: Protects spine during high-impact activities
• Postural control: Supports proper athletic positioning and technique
• Breathing mechanics: Assists in controlled breathing under exertion

Research by Robert Wood shows that athletes who fail this test have significantly higher rates of lower back complaints and reduced performance in rotational sports movements.

Sport-Specific Applications

Different sports place varying demands on the abdominal muscles tested in Kraus-Weber Test 2:

Rotation-Heavy Sports (Baseball, Golf, Tennis)

Athletes in these sports require exceptional abdominal strength for rotational power. Professional baseball pitchers and tennis players typically perform this test with ease, as their sports demand constant eccentric and concentric abdominal contractions. A failure on Test 2 indicates potential vulnerability to oblique strains during serving or throwing motions.

Endurance Sports (Running, Cycling, Triathlon)

While endurance athletes develop strong leg muscles, abdominal weakness is common. According to research, approximately 30-40% of recreational runners fail Test 2 despite good cardiovascular fitness. Strong abdominals prevent excessive anterior pelvic tilt and maintain running economy during fatigue.

Team Sports (Soccer, Basketball, Football)

Team sport athletes benefit from passing all 6 Kraus-Weber tests, with Test 2 being particularly important for change-of-direction movements. Strong abdominals allow rapid deceleration and re-acceleration without excessive spinal stress. Elite soccer players consistently pass all tests and typically hold plank positions for 3+ minutes.

Strength Sports (Weightlifting, Powerlifting, CrossFit)

Ironically, some strength athletes fail Test 2 despite lifting heavy weights. This occurs when training focuses exclusively on loaded movements without bodyweight core control. Passing the Kraus-Weber tests ensures athletes have fundamental movement patterns before progressing to heavy loaded exercises.

The Science Behind Test 2

The bent-knee position in Test 2 serves a specific biomechanical purpose. It was found that bending the knees reduces psoas activation by approximately 60-70%, placing primary demand on the rectus abdominis and obliques.

When comparing Test 1 (straight legs) and Test 2 (bent knees):

• Test 1 with straight legs: Requires combined abdominal and psoas strength (hip flexors)
• Test 2 with bent knees: Isolates abdominal muscles by mechanical disadvantage to psoas

Athletes who pass Test 1 but fail Test 2 typically have strong hip flexors masking weak abdominals. This pattern is common in sprinters and jumpers. Conversely, passing Test 2 but failing Test 1 suggests adequate abdominal strength but weak hip flexors, often seen in upper-body dominant athletes.

Modified Scoring System

While the standard Kraus-Weber test uses pass/fail scoring, a modified system scores each test from 0-10 points based on movement quality and hold duration. This allows for more nuanced assessment:

• 10 points: Complete movement with perfect form
• 5-9 points: Partial movement or form breakdown
• 0-4 points: Minimal movement or unable to initiate

For athletic populations, sports science expert Robert Wood recommends scoring all 6 tests to identify subtle weaknesses that could impact performance or increase injury risk.

Training to Improve Test 2 Performance

If you failed Test 2, focus on progressive abdominal strengthening:

Week 1-2: Foundation Phase

• Dead bugs: 3 sets of 10 reps - Lie on back, arms extended up, alternate lowering opposite arm and leg
• Hollow body holds: 3 sets of 20 seconds - Maintain lower back flat against floor
• Curl-ups: 3 sets of 15 reps - Hands under lower back, curl up 30 degrees

Week 3-4: Strength Development

• Bicycle crunches: 3 sets of 20 reps - Focus on rotation and full range
• V-sits: 3 sets of 10 reps - Progress toward full range
• Plank variations: 3 sets of 30-45 seconds - Front and side planks

Week 5-6: Test-Specific Training

• Assisted sit-ups: 3 sets of 8-10 reps - Use minimal assistance to complete full range
• Eccentric sit-ups: 3 sets of 5 reps - Slowly lower from seated to supine position (5 second count)
• Retest Kraus-Weber: Assess progress and adjust training

Data compiled by Robert Wood shows that 85% of athletes who failed Test 2 initially could pass within 6-8 weeks of focused abdominal training.

Common Mistakes and How to Avoid Them

Mistake 1: Using momentum - The sit-up must be a controlled muscular contraction, not a ballistic swing. Perform the movement slowly (2 second up, 1 second pause, 2 second down) during training.

Mistake 2: Pulling with hands - Hands behind neck should provide light support only. Pulling the head forward with hands invalidates the test and can strain the neck. Keep elbows wide.

Mistake 3: Inadequate warm-up - Cold muscles perform poorly. Complete 5-10 minutes of light movement and dynamic stretching before testing. Include cat-cow stretches and torso rotations.

Mistake 4: Testing too frequently - Allow 4+ weeks between retests to see meaningful strength adaptations. Weekly testing provides no benefit and may cause overtraining.

Mistake 5: Ignoring Test 1-6 context - Test 2 is one component of comprehensive core assessment. Athletes should pass all 6 tests for complete postural fitness.