Functionality assessment Indices and Scales


  1. Body Mass  Index
  2. ASA Physical status assessment 
  3. Calculator of Free testosterone
  4. Bladder capacity calculation
  5. Pelvic floor muscle assessment scale
  6. POP-Q Quantification System
  7. ASIA Spinal cord impairment classification
  8. Assessment of testicular volume  and penis length


Body Mass Index

The Body Mass index (BMI) is a widely used diagnostic tool for assessing body weight. Its was invented by Adolphe Quetelet (1832).

BMI is calculated as shown below:

BMI = weight (kg) / height(m)



Table 1: Body volume  index categorization
<18.5 Underweight
18.5-24.9 Normal
25.0-29.9 Overweight
>30 Obese
>40 Morbidly obese

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ASA Physical Status Assessment

The physical status classification system of the American Anaesthesiologist Society was created in 1941, aiming at assissing the physical condition of a patient prior to selecting the type of anaesthesia to be used or the performance of a surgical procedure.

The description of a patient’s pre-op physical status is used so as to improve data recording and facilitate communication amongst physicians; it also helps as a uniform statistical analysis system. The classification is not intended for the prediction of intraoperative risk.

Modern classification comprises six categories, as described below:

ASA Category 

Pre-op health status

Comments / Examples

Table 2: ASA Assessment Table according to physical status


Healthy patient

Without physical, physiological or mental disorders. Extremely young and old ages are exempted. Healthy individuals tolerating physical exercise well


Patients with mild systemic disease

Withoutactivity limitation. Well- controlled condition of one of the body's systems. Controlled hypertension or diabetes without systemic complications, smoking without chronic obstructive pulmonary disease (COPD), mild obesity, pregnancy


Patients with serious systemic disease

There is activity limitation. Controlled condition of one or more systems. There is no immediate danger of death. Congestive Heart Failure (CHF), stable angina, past heart episode, uncontrolled hypertension, morbid obesity, chronic renal failure, bronchial asthma with periodic symptoms


Patient with a serious systemic disease under constant threat of death


There is at least one serious illness that is not sufficiently controlled or is at its final stages. There is risk of death. Unstable angina, symptomatic COPD, symptomatic CHF, liver and kidney failure



Patients who are not expected to survive without the operation

They are not expected to survive without surgery for more than 24 hours. There is immediate risk of death. Multiple organ failure, septic syndrome with hemodynamic instability, hypothermia, uncontrolled coagulation dysfunctions


Brain dead patient who is to become an organ donor


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Calculator of Free Testosterone


Free testosterone cannot be reliably measured in a direct manner.

This is why lab measurements of albumin, SHBG and testosterone are taken, and then a formula is used to calculate free testosterone; the formula can be found at the following link:

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Bladder Capacity Calculation

Calculation of normal maximum expected urinary bladder capacity during childhood


  • 1. The commonest mathematical formula was based on the observation that the capacity of a child's bladder increases by approximately 30ml per year up to the age of 8.

    According to this formula, the expected capacity of a child's bladder is Y = 30 +30X, where Y is bladder capacity in ml and X is age in years. (Picture 1)

  • 2. A second mathematical formula was based on the discovery that the relationship of age and capacity is not linear.

    Thus, for infants aged <2 the following equation was proposed: Y = (SX + 2)28.35ml, while for children aged >2 the following equation was proposed: Y = (X/2 +6)28.35ml, where Y is bladder capacity in ml and X is age in years. (Picture 2)


Kirk J, Rasmussen PV, Rittig S and Djurhuus JC. Micturition habits and bladder capacity in normal children and in patients with desmopressin-resistant enuresis. In: Nørgaard JP, Djurhuus JC, Hjälmås K, Hellström A.-L and Jørgensen TM (eds.). Proceedings, Second International Workshop, International Enuresis Research Center, Aarhus. Scand J Urol Nephrol 1995; 173: 49-50.

Akbal C, Genc Y, Burgu B, Ozden E, Tekgul S. Dysfunctional voiding and incontinence scoring system: quantitative evaluation of incontinence symptoms in pediatric population. J Urol. 2005; 173: 969-73.

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Pelvic Floor Muscle Assessment cale


Pelvic floor muscles are assessed and ranked on the Oxford Table, like all skeletal muscles.

The Guideline Task Force of the Physiotherapy Association in England proposed the Oxford System as a standard method for assessing incontinence. The system has proved to offer trial-countercheck credibility.

This vaginal assessment of pelvic floor muscles allows for the planning of exercise regimens and is now a standard “international tool” for health professional communication and comparative study reports. The method describes the strength of the pelvic floor muscles on a scale from 0 to 5

Often, specialist pelvic floor physical therapists add the symbols +/-, in order to indicate intermediate conditions.



Proposed physical therapy

Table 3: Assessment scale of pelvic floor muscles


none electric stimulation or biofeedback


very weak (slight movement felt by examiner's finger) electric stimulation or biofeedback


weak (mild feeling of tension on examiner's finger) electric stimulation or biofeedback


moderate (the posterior vaginal wall elevates) pelvic floor muscle regimen


good (the posterior vaginal wall elevates, despite the resistance of the examiner's finger) pelvic floor muscle regimen


strong (the examiner's finger is squeezed) pelvic floor muscle regimen (preventively)

The scale used for the assessment of pelvic floor muscles in the overall assessment system proposed by Laycock and Jerwood is internationally known as “The PERFECT Scheme”. It is a reliable method that records the strength, stamina, repetitions and number of quick contractions that the patient can perform before muscular fatigue.


Power (pressure)

Strength (according to  the Oxford Scale)

Table 4: Pelvic floor muscle assessment scale


Endurance Stamina (time before strength decreases by 35%)


Repetitions Contraction repetitions with 4 second rest intervals (maximum of 10)


Fast Fast contractions after 1 minute's rest (maximum of 10)


Every Contraction Timed Reminder: record both the number of contractions and the duration of each contraction

For every patient, the complete assessment includes 4 numbers, reflecting power/duration/repetitions/quick contractions. Thus, the assessment of the pelvic floor muscles can be reported as follows: 4/6/5//9

This assessment is analysed as follows:

  • 4 = good contraction(power according to the Oxford Scale)
  • 6 = 6 second duration (contraction duration)
  • 5 = number of repetitions
  • 9 = quick contractions (following one minute's rest)


Literature References

Laycock, J., Jerwood, D. (2001) Pelvic floor assessment the PERFECT scheme. Physiotherapy. 87: 12: 631-642.

Konstantinidou, E. The Role of Training Pelvic Floor Muscles in Stress Incontinence Treatment. Physical Therapy, 8(4), 213-220, 2005.


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POP-Q Quantification System

Cystocele, rectocele and uterine prolapse often concern Urologists and Gynaecologists. Prolapse quantification is important for the prognosis of post-operative outcomes, as well as for research purposes.

Many classifications have been proposed over the years and have been presented quite successfully in Mouritsen's article (Mouritsen L. Best Pract & Res Clin Obstet Gynaecol. 2005; 6: 1-17).

The International Continence Society has proposed the following classification (Bump et al, Am J Obstet Gynecol 1996; 75:1)

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ASIA Spinal cord impairment classification

ASIA impairment Scale

Injuries to the spinal cord are classified based on the scale of the  American Spinal Injury Association - ASIA





Neurological picture
Table  5: ASIA Scale of Spinal impairment classification 


Full (there is no function)

Lack of morot or sensory function at the S4-S5 spinal 


Imperfect: only motory function preserved

Lack of motor function as well as imperfect sensory function below the level of spinal cord damage.


Imperfect: partial motor and sensory function preserved

Presence of motor function below the level of spinal cord damage, with at least half of the key muscles below the damage retaining muscle power lower than level 3.


Imperfect: basic motor functions preserved

Presence of motor function below the level of spinal cord damage with at least half of the key muscles below the damage retaining muscle power of at least level 3.


Normal functionality

Normal motor and sensory function below the level of damage.

Click here to find a special neurological assessment form

You can also find instructions on neurological assessment.

  • In patients with spinal a cord injury InSTeP

  • In children with spinal cord injury WeeSTeP

  • In patients with autonomous neuropathy ASTeP

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Assessment of testicle volume and penis length


Testicle volume in adult life ranges between 15-25ml.

Average penis length during erection is 13cm.

Growth is completed at 14 years of age. Therefore, any hormonal intervention must be made early on.




Tanner Staging

Table 6: Tanner Stage Scale

Tanner I: Prepubescent (volume smaller than 1.5ml, small penis length 3cm or less) [typical of ages 9 and younger].

Tanner II: Volume of testicles between 1.6 and 6ml. The skin of the scrotum grows thinner, takes on a red shade and grows. Penis length unchanged [ages 9-11]

Tanner III:  Testicle volume between 6 and 12ml. Further enlargement of scrotum. Penis length approximately 6cm [ages11-12.5]

Tanner IV:  Testicle volume between 12 and 20ml. Further enlargement of scrotum, which takes on a darker colour.  Penis length approximately 10cm and girth increase [ages 12,5-14].

Tanner V: Testicle volume greater than 20ml. Adult scrotum. Penis length 15cm [ages 14+]

Penis length in children


Penis length (in cm)

(mean value ± standard deviation)

Table 7: Table by Feldmann and Smith on Microphallus (Micropenis)


0-5 months


6-12 months


1-2 years


2-3 years


3-4 years


4-5 years


5-6 years


6-7 years


7-8 years


8-9 years


9-10 years


10-11 years




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