Graduate from 'Just Measuring'! A Summary of Essential Physical Function Assessments and Cut-off Values in Cardiac Rehabilitation (Grip Strength, SPPB, 6MWT)
Hello, this is Yu-ki.
Before starting a patient's rehabilitation, I believe you perform 'physical function assessments' as a routine. However, have you ever felt like this?
✅ “I’m just measuring walking speed and grip strength for now”
✅ “I’m satisfied just by writing the measured values in the medical record”
✅ “I’m not sure which tests to prioritize...”
In the midst of busy clinical practice, it tends to become just a 'task of measuring'.
However, assessments in cardiac rehabilitation are
👉 “super important” data that predicts a patient's return to society and lifespan (prognosis).
This time, I will explain the 'standard physical function assessments' that you absolutely must master in cardiac rehabilitation, along with the cut-off values (reference values) that indicate 'below this is dangerous!'
1. Is being thin more dangerous? 'Obesity Paradox'
First, let's look at the basic assessments such as height, weight, and skeletal muscle mass.
Here, there is an important point unique to heart failure patients.
💡 Yu-ki's Quick Note: Obesity Paradox
Generally, obesity is considered a health risk, but in heart failure patients, “those who are slightly obese (chubby) have a better prognosis than those who are thin” is a phenomenon that has been reported.
Conversely, “thinness (underweight/muscle loss)” is a strong factor for poor prognosis. Unintentional weight loss (such as cachexia) requires special attention.
2. A mirror reflecting prognosis: 'Sarcopenia Assessment'
Muscle strength is a mirror that reflects 'prognosis'. Be sure to measure the following two.
① Grip strength (indicator of whole-body muscle strength)
In heart failure patients, decreased grip strength increases the risk of cardiac events by 'about 4 times'.
🚨 Sarcopenia Diagnostic Criteria (AWGS 2019)
👨 Men: Less than 28kg
👩 Women: Less than 18kg 👉 If it is below this, it is judged as 'muscle weakness present'.
② Isometric knee extension strength (measured with HHD) This is important for walking ability and achieving 'activities of daily living independence level (4METs)'.
🎯 Target value
50% of body weight (0.50 kgf/kg) or more (*For elderly patients with heart disease)
3. 'Fall Risk Assessment' to Prevent Bedridden States
Falls and fractures in heart failure patients significantly increase the risk of becoming bedridden, so early detection is key.
① SPPB (Short Physical Performance Battery) A globally used assessment that combines three elements: 'balance,' 'gait,' and 'chair stand.'
🚨 Cut-off value
8 points or less (out of 12 points) 👉 Judged as having a high possibility of sarcopenia or frailty.
② TUG (Timed Up and Go test)
Measures the time to 'sit down → stand up → walk 3m → turn → return and sit down.'
🚨 Cut-off value
13.5 seconds or more (High risk of falls for community-dwelling elderly)
③ One-leg standing test (static balance) 🎯 Reference standards
Independence in indoor walking: 5 seconds or more
Putting on/taking off socks: 20 seconds or more
4. 'Exercise Tolerance' to Quantify Physical Strength
① 6-Minute Walk Test (6MWT)
Measures 'how far one can walk in 6 minutes,' which has a high correlation with Peak VO2.
🚨 Sign of poor prognosis
Less than 300m
⚠️ Absolute rule during implementation
The global rule is to only inform the patient of the remaining time every minute (e.g., '〇 minutes remaining') and do not offer encouragement such as 'Keep it up!'.
5. Summary
The purpose of physical function assessment is not simply to collect data.
Low grip strength 👉 'Is nutritional guidance (protein intake) also necessary?'
If TUG is slow 👉 'I need to adjust the home environment (handrails, etc.) before discharge.'
In this way, it is a tool (compass) for connecting to concrete support.
Please make sure to note the cut-off values introduced this time in the corner of your chart board and use your daily assessments for 'prognostic prediction'!
👉 For detailed 'measurement protocols,' visit the blog
'What is the difference between the Jamar and Smedley types of grip strength meters?' 'How do you prevent compensatory movements when measuring knee extension strength?'
For those people, the blog explains the correct measurement methods (posture and angles) for each test in detail with illustrations.
If the measurement method (protocol) is off, the data cannot be compared, so please be sure to check it at least once!
▼ [Archived Version] Standard Physical Function Assessment Manual for Cardiac Rehabilitation | Cut-off Values and Practical Methods https://rehaheartlab.com/physical_assessment/
(Click here for more precise physical fitness assessment 'CPX')
▼ Interpretation and Practice of Key CPX Indicators https://rehaheartlab.com/heartreha_cpx/