Page 41 - JSOM Summer 2022

Special Operator’s body fat percentage has little significance Case Presentation 2
until it is associated with desired physical performance out- Full ISAK profile was completed by a level 3 anthropometrist
comes, low incidence of injury and illness, and sustainable on a male Air Force Explosive Ordnance Disposal (EOD): aged
1
lifestyle factors.” In the next section, we present a case series 31 years, body mass 69 kg, height 175 cm, and BMI 22.6kg/
demonstrating application of the ISAK profile in a SOF Hu- m . The Operator competed as a Wounded Warrior following
2
man Performance facility. multiple surgeries on both knees due to combat injuries. He has
medaled in sprint track and field events and earned an invita-
tion to the Invictus Games. Sum of six skinfolds totaled 47.6
Case Series
mm, body fat was calculated as 11.0% using the Yuhasz for-
Case Presentation 1 mula, and muscle:bone ratio was 4.6. A lower muscle:bone
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Full ISAK profile was completed by a level 3 anthropometrist ratio with lean physique is better suited for sprinting events
on a male Air Force Joint Terminal Attack Controller: aged 33 than the high (>5) muscle:bone ratio found in many Operators,
2
years, body mass 110 kg, height 176 cm, and BMI 35.6kg/m . because carrying excess mass would slow his speed. In another
BMI would suggest obesity; but the ISAK profile shows that sport characterized by shorts bursts speed, elite rugby players
adipose mass was below average, and the Operator carries high have similar average muscle:bone ratios ranging from 4.5 to
muscle mass not evident from the standard waist:neck ratio cal- 4.7. Although little data have been published on muscle:bone
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culated by military body fat standards. His muscle:bone ratio ratios in sprinters, the mean somatotype found in internation-
of 6.1 was well above average, showing he carries maximum ally competitive 100-m sprinters is ectomorphic mesomorph
muscle for his frame. His sum of six skinfolds totaled 91.2 mm, category. The Operator presented in the case study has a sim-
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and his body fat was calculated as 17.7% using the Yuhasz ilar somatotype, indicating a lean muscular physique is advan-
formula. The Operator complained of loss of mobility and tageous for short sprints (Figure 2).
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agility, likely related to a muscular imbalance at the hips. His
high muscularity around the hips (wide gluteal girth, low skin-
fold thickness) compared to average bone length and breadths FIGURE 2 Somatotype of an Air
Force EOD Wounded Warrior
at the hip joint stress the bones and joints beyond their func- athlete who has medaled track
tional capacity and contributes to loss of agility (Figure 1). The and field events.
Operator had begun yoga training to improve flexibility, but
without altering his muscle:bone ratio at the hip joint, he will His somatotype (1.8–5.7–2.6)
fit the ectomorphic mesomorph
likely continue to experience his described symptoms. category, similar to competitive
international 100-m sprinters. 19
FIGURE 1 Five-way fractionation of Air Force JTAC.

Authors observe the average somatotype for men within Spe-
cial Operations to be predominantly mesomorphy, which is
very similar to elite rugby somatotype data. Interestingly, the
muscle:bone ratios in elite rugby tend to be slightly lower
than the average muscle:bone ratios observed in Special Op-
erations, which could be attributed to overall bone mass and
(A) Muscle mass contributed more than half of Operator total body height differences between the populations. This indicates a
mass. (B) Hip girth was 3 standard deviations above phantom human greater load derived from muscle mass within Special Oper-
reference, yet pelvis width and femur length were much smaller. Low ations. Due to the quantification of somatotyping, with ap-
front thigh skinfold thickness indicates wide hip girth is due to muscle propriate military task specific measures, there is a potential
rather than adipose. This extreme muscularity compared to the bones capability for comparing performance and/or physique charac-
at the joint may have led to a muscular imbalance that contributed to
Operator loss of mobility and agility. teristics of Soldiers at various deployment cycles and/or injury
frequency. The use of somatotyping is limited to general de-
Within male combat Operators, authors observe an average scriptors, meaning more precise measurements with the ISAK
muscle:bone ratio range of 4.8–5.3. Contingent on their occu- protocol are necessary to provide individual and/or periodized
pation, lower muscle:bone ratios may require greater strength adjustments.
for their role. For example, a Green Beret needs to be able
to complete endurance ruck movements under 75–80 lb load Case Presentation 3
carriage, with short bursts of sprints at any given point. An- Full ISAK profile was completed by a level 3 anthropometrist
ecdotally, Soldiers who maintain muscle:bone ratios between on a male Navy Explosive Ordinance Disposal (EOD): aged
4.8 and 5.0 report more functional range of motion, fewer 29 years, body mass 88 kg, height 177 cm, and BMI 28.1kg/
injuries, less frequent reactive maintenance with physical m . The Operator’s goal was to reduce body fat; therefore,
2
therapy, and negligible degradation in strength. When the ra- he worked with a Human Performance Dietitian to follow an
tio increases to 5.0–5.2, Soldiers report feelings of heaviness individualized nutrition protocol. Longitudinal progress was
on joints during running, although they maintain optimal tracked using the ISAK profile, showing that the Operator lost
strength without chronic pain. Soldiers who exceeding ratio of 6 kg over 5 months while maintaining muscle mass. Table 1
5.3 generally want the aesthetic appearance of larger mass size shows changes in body composition using ISAK assessed five-
for their occupation, yet they also report increased joint pain, way fractionation. The Operator’s body mass decreased from
decreased mobility, more frequent reactive maintenance visits 88.1 to 82.2 kg while his body fat decreased from 15.7%
with physical therapy, and/or more frequent musculoskeletal to 12.3% (Yuhasz formula), yet he maintained muscle:bone
injuries. ratio of 5.4. This case demonstrates the utility of the ISAK
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Assessing Body Composition Using Kinanthropometry | 39