Jordan Hale

Rugby · 9/4/2026 · KRS-27 phantom scaled

Legacy Z25 teaching reference. The KRS-27 values have not been independently sourced or validated. Bands and indices below are illustrative, not muscle diagnoses, clinical thresholds or treatment recommendations.

Illustrative index

63/100

Symmetry SI

1.8%

Phantom index

BMI (descriptive)

26.6kg/m²

Cartography

Sage fill scales with stature-adjusted z versus KRS-27.

Regional development

Bilateral symmetry

Deltoid

2.0%

Upper arm

2.5%

Forearm

2.4%

Thigh

0.9%

Calf

1.3%

Rear deltoid

2.1%

Latissimus

2.4%

Triceps

2.6%

Gluteal

0.8%

Hamstring

1.1%

Zone table

Zone	cm	Scaled	z	Band
Chest Width	35.1	32.8	0.10	Near demo reference
L Deltoid	41.2	38.5	0.76	Upper demo band
R Deltoid	40.4	37.8	0.49	Near demo reference
L Upper Arm	36.8	34.4	1.23	Upper demo band
R Upper Arm	35.9	33.6	0.91	Upper demo band
L Forearm	30.1	28.1	0.79	Upper demo band
R Forearm	29.4	27.5	0.41	Near demo reference
Waist	86.2	80.6	0.68	Upper demo band
Chest Circ.	108.4	101.4	0.56	Near demo reference
L Thigh	64.2	60.0	0.55	Near demo reference
R Thigh	63.6	59.5	0.42	Near demo reference
L Calf	40.1	37.5	0.28	Near demo reference
R Calf	39.6	37.0	0.09	Near demo reference
Upper Traps	46.8	43.8	1.19	Upper demo band
L Rear Delt	39.4	36.8	0.67	Upper demo band
R Rear Delt	38.6	36.1	0.38	Near demo reference
L Lat Width	34.2	32.0	0.99	Upper demo band
R Lat Width	33.4	31.2	0.70	Upper demo band
L Tricep	35.1	32.8	0.97	Upper demo band
R Tricep	34.2	32.0	0.63	Upper demo band
Lower Back	88.4	82.7	0.37	Near demo reference
L Glute	102.2	95.6	0.14	Near demo reference
R Glute	101.4	94.8	0.00	Near demo reference
L Hamstring	61.8	57.8	0.47	Near demo reference
R Hamstring	61.1	57.1	0.32	Near demo reference

Proportionality ratios

Waist : chest0.80
Descriptive girth ratio. No validated target or performance inference.
Thigh : calf1.60
Descriptive girth ratio. No validated target or performance inference.
Quad girth : ham girth1.04
Descriptive girth ratio. No validated target or performance inference.
Arm : chest0.34
Descriptive girth ratio. No validated target or performance inference.
Gluteal : waist1.18
Descriptive girth ratio. No validated target or performance inference.

Interpretation boundary

Automated exercise prescriptions are disabled. Girth measurements do not establish muscle strength, activation, injury risk or a need for treatment.

Methods note

Measured girths are retained in centimetres. Scaled values use a stature reference of 170.18 cm. The legacy KRS-27 comparison table is unverified; use it only to demonstrate calculations, not as a normative population.