Defining Athletic Archetypes in Fast Bowling: Hip- and Knee-Dominant Bowlers and ISA Angle

Due to the incredible interest and application of the Pacelab Classification system this article will provide an insight into an aspect of the hip and knee dominance system based on their Infrasternal Angle (ISA). This is an aspect I only cover for those affiliated coaches but as the system grows I'm keen for all the right information to be in the hands of all coaches. There are too many players, academies and coaches using the system that I designed 8 years ago incorrectly. Correct application does not require interpretation. Simply follow the guidelines and the exact system that has changed the fast bowling landscape.

So what is ISA?

Fast bowlers exhibit diverse athletic profiles shaped by biomechanics, training, and genetic predispositions. One valuable way to categorise these archetypes is through their Infrasternal Angle (ISA), a biomechanical marker that correlates with distinct physical attributes and movement patterns. By aligning ISA with the archetypes of hip- and knee-dominant bowlers, coaches can tailor training to optimise performance.

1. Wide Infrasternal Angle (ISA)

Characteristics

A wide ISA, greater than 90 degrees, is often associated with a broad ribcage and robust chest structure.

Attributes in Fast Bowling

Wide ISA bowlers often lean towards knee-dominant mechanics, relying heavily on quadriceps-driven force production. Their natural build supports high force application into the ground, enabling powerful delivery strides and strong follow-throughs.

Strengths

? Power/Strength-Driven Mechanics: These bowlers excel in generating high ball speeds through brute force and strong ground interaction.

? Efficient Breathing Mechanics: The broad ribcage supports better lung expansion, enabling prolonged performance under fatigue.

Training Focus

Wide ISA bowlers benefit from lower-body strength work emphasising knee-dominant patterns (e.g., squats) alongside rotational strength and thoracic mobility drills to optimise their delivery mechanics.

2. Neutral Infrasternal Angle (ISA)

Characteristics

A neutral ISA, around 90 degrees, reflects a balanced build without pronounced leanings towards narrow or wide archetypes.

Attributes in Fast Bowling

Neutral ISA bowlers often exhibit a hybrid of hip- and knee-dominant mechanics. The 'in-betweener' in the PaceLab classification system. They demonstrate adaptability in movement patterns and can adjust their technique to meet the demands of various bowling surfaces and match conditions.

Strengths

? Versatility: These bowlers balance speed and power, excelling across diverse playing conditions.

? Balanced Kinetic Chain: They display harmony in strength, mobility, and coordination, contributing to consistent performance.

Training Focus

Neutral ISA bowlers should focus on general physical preparation (GPP), enhancing both hip- and knee-dominant mechanics with exercises like Bulgarian split squats and deadlifts while maintaining mobility through dynamic stretching and plyometric drills.

3. Narrow Infrasternal Angle (ISA)

Characteristics

A narrow ISA, less than 90 degrees, is associated with a tapered ribcage and lean upper body.

Attributes in Fast Bowling

Narrow ISA bowlers often exhibit hip-dominant mechanics, leveraging the posterior chain for explosive speed and rotational power. They typically generate rapid arm speed and efficient force transfer, crucial for delivering the ball at high velocities.

Strengths

? Speed and Agility: Narrow ISA bowlers excel in sprint-like movements and fast arm actions, critical for rapid bowling actions.

? Efficient Force Transfer: Their build enhances elastic energy storage and transfer, optimising ball release velocity.

Training Focus

Narrow ISA bowlers thrive on exercises targeting the posterior chain (e.g., Romanian deadlifts, hip thrusts) and reactive drills for improving elastic energy utilisation. Thoracic extension and rotational drills are essential to maintain balance and prevent overuse injuries.

Conclusion

ISA-based archetypes offer a biomechanical lens through which coaches can refine training for fast bowlers. Whether hip- or knee-dominant, understanding an athlete’s ISA informs tailored programming that leverages their unique strengths.

By aligning ISA insights with individualised plans, fast bowlers can optimise their mechanics, minimise injury risk, and unlock their full potential on the cricket field.

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