Relative Grip Strength: Calculation, Interpretation, and Improvement

How do you calculate relative grip strength?

Relative grip strength is calculated by dividing your absolute grip strength (measured in kilograms or pounds) by your body weight (in kilograms or pounds), providing a normalized measure of strength proportionate to your body size.

Understanding Grip Strength: A Vital Biomarker

Grip strength, often overlooked in standard fitness assessments, is a powerful indicator of overall muscular strength, upper body function, and even general health. It reflects the strength of the muscles in the forearm and hand responsible for crushing, pinching, and supporting. While absolute grip strength simply measures the maximum force you can exert, relative grip strength normalizes this measure against your body weight, offering a more nuanced perspective on your functional strength and capacity, especially relevant for activities where body weight support or manipulation is key.

What is Relative Grip Strength?

Relative grip strength provides context to your raw grip strength score. A very strong individual might have a high absolute grip strength, but if they are also very heavy, their relative grip strength might not be as impressive compared to a lighter individual with a similar absolute score. This metric is particularly useful for:

• Athletes: Comparing strength across weight classes or sports where strength-to-weight ratio is critical (e.g., gymnastics, climbing, wrestling).
• Fitness Enthusiasts: Tracking functional strength improvements independent of body weight fluctuations.
• Health Assessments: Research suggests relative grip strength can be a better predictor of certain health outcomes, such as sarcopenia risk and functional independence in older adults, than absolute grip strength alone.

Essential Equipment

To accurately calculate relative grip strength, you will need:

• Hand Dynamometer: This is the standard tool for measuring absolute grip strength. Various models exist, from hydraulic to electronic, but ensure it's calibrated and capable of measuring in kilograms (kg) or pounds (lbs).
• Body Weight Scale: A reliable scale to accurately measure your current body weight in kilograms (kg) or pounds (lbs).

Measuring Absolute Grip Strength: The Foundation

Before calculating relative grip strength, you must first obtain an accurate measurement of your absolute grip strength. Consistency in technique is paramount for reliable results.

Procedure for Measuring Absolute Grip Strength:

• Positioning: Stand upright with your feet shoulder-width apart. Hold the hand dynamometer in one hand, with your arm straight down at your side, elbow slightly flexed (around 15-30 degrees), and not touching your body. The dynamometer should be positioned so that the base rests on the first metacarpal (thumb side) and the handle rests on your four fingers.
• Setting: Ensure the dynamometer's handle is adjusted to comfortably fit your hand, allowing for maximal grip.
• Execution: Take a deep breath, and on the exhale, squeeze the dynamometer as hard as possible for 3-5 seconds. Ensure a maximal, sustained effort. Avoid using other body parts (e.g., leaning, swinging) to assist the squeeze.
• Trials: Perform at least two to three trials with each hand, allowing for 30-60 seconds of rest between attempts. Record the highest reading for each hand.
• Dominant Hand: For most assessments, the score from your dominant hand is typically used for the relative grip strength calculation, as it usually represents your peak capacity. However, recording both can be insightful.

Key Considerations for Accurate Measurement:

• Warm-up: A brief warm-up (e.g., light forearm stretches, gentle squeezes) can help improve performance and reduce injury risk.
• Time of Day: Grip strength can fluctuate throughout the day. For consistency, try to measure at the same time for subsequent assessments.
• Hydration and Fatigue: Ensure you are well-hydrated and not overly fatigued from recent training.

The Relative Grip Strength Calculation

Once you have your absolute grip strength (in kg or lbs) and your body weight (in kg or lbs), the calculation is straightforward. Ensure both measurements are in the same unit system (e.g., both kilograms or both pounds).

Formula:

Relative Grip Strength = Absolute Grip Strength (kg or lbs) / Body Weight (kg or lbs)

Example:

Let's say an individual's:

• Absolute Grip Strength (dominant hand) = 55 kg
• Body Weight = 75 kg

Relative Grip Strength = 55 kg / 75 kg = 0.73

If using pounds:

• Absolute Grip Strength (dominant hand) = 121 lbs (approx. 55 kg)
• Body Weight = 165 lbs (approx. 75 kg)

Relative Grip Strength = 121 lbs / 165 lbs = 0.73

The ratio remains the same regardless of the unit system, as long as both numerator and denominator are consistent.

Interpreting Your Relative Grip Strength Score

Interpreting your relative grip strength score requires comparing it to normative data, which can vary significantly based on age, sex, and population. While definitive universal standards are still evolving, general benchmarks can provide a useful guide.

General Benchmarks (Approximate Ratios):

• Excellent: 0.75 and above
• Good: 0.65 - 0.74
• Average: 0.55 - 0.64
• Below Average: 0.45 - 0.54
• Poor: Below 0.45

Note: These are general guidelines. For more precise interpretation, consult studies specific to your demographic (age group, sex, athletic background).

Significance of Your Score:

• High Relative Grip Strength: Often associated with better overall health, lower risk of chronic diseases, greater longevity, and superior athletic performance in sports requiring high strength-to-weight ratios.
• Low Relative Grip Strength: Can indicate general weakness, increased risk of sarcopenia (age-related muscle loss), frailty, and impaired functional independence, particularly in older adults. It may also point to a need for targeted strength training.

Factors Influencing Grip Strength

Several factors can influence your grip strength, both absolute and relative:

• Age: Grip strength typically peaks in the 20s and 30s and gradually declines with age.
• Sex: Men generally have higher absolute grip strength than women, though relative grip strength differences can be less pronounced.
• Training Status: Individuals engaged in regular strength training, especially exercises targeting the forearms and back (e.g., deadlifts, pull-ups), tend to have stronger grips.
• Hand Dominance: The dominant hand is typically stronger, though bilateral training can reduce this discrepancy.
• Body Composition: While the relative calculation accounts for body weight, a higher proportion of lean muscle mass can contribute to better grip strength.
• Fatigue and Injury: Acute fatigue or previous injuries to the hand, wrist, or arm can temporarily or permanently reduce grip strength.

Enhancing Your Grip Strength

If your relative grip strength score indicates room for improvement, incorporating specific exercises can be highly effective:

• Deadlifts: A foundational exercise that heavily taxes grip strength, especially with heavier loads.
• Farmer's Carries: Walking while holding heavy dumbbells or kettlebells significantly improves crushing and support grip.
• Pull-ups/Chin-ups: Excellent for developing endurance and static grip strength. Variations with thicker bars or towels increase the challenge.
• Plate Pinches: Holding weight plates together with your fingers strengthens pinch grip.
• Bar Hangs: Simply hanging from a pull-up bar for time builds endurance and static grip.
• Hand Grippers: Devices specifically designed to improve crushing grip.

Conclusion

Calculating relative grip strength provides a valuable, normalized metric that goes beyond raw power. By understanding this calculation and its interpretation, you gain a deeper insight into your functional strength, overall health, and athletic potential. Regular measurement and targeted training can help you improve this crucial aspect of your physical fitness, contributing to a stronger, healthier, and more capable you.