Lay Of The Land
Football (soccer) continued to be a growing sport around the world and in Canada. In 2024 and in Calgary alone, Calgary Minor Soccer Association has registered 31,319 athletes within 2,027 teams; a 15% increase in registration numbers over the last 3 years. RAMP, the popular soccer registration app, registered 82,000 players and the Alberta soccer annual report totaled 38,722 players registered for indoor, 82,454 players registered for outdoor, and 7,765 staff members. With an increase in participation many questions arise when it comes to safety. Injury prevention initiatives focus on factors at the levels of organizations (eg. game/practices times, rules, policy, etc), athlete and team level (warm ups, training sessions, strength and conditioning, etc), and the equipment level (eg. cleats, shin pads, etc.).
A frequent question has been posed to us and many soccer store owners, which I remember as a young athlete asking myself. What boot should I get? With my primary concern being what stud pattern is best? The bigger more aggressive the better right?
Cleat selection is primarily based on playing surface and stud pattern for performance, but does the stud pattern actually change performance and more importantly how does it affect injury risk and why?
Lower extremity injuries are the most frequent injuries experienced in soccer, making up 70% of all soccer related injuries. The Injury Consensus Group established the injury rates of soccer related injuries are 5.8/1,000hr in training, 30.5/1,000h in matches, and raising to 60/1,000h in higher competition. Half of these injuries are considered severe, meaning the injury is significant enough to sideline athletes for more than 4 weeks. Non-contact injuries prevail over contact injuries, making up 59% of all lower extremity injuries.
Stud Patterns in Football Boots: Purpose, Biomechanics and Injury Risk
What Is the Current Overarching Purpose of Different Stud Patterns and Football Boots?
The essential function of football boots is to support players during complex maneuvers such as acceleration, deceleration, and sharp changes in direction. The studs that cover the sole are designed to provide extra traction on the pitch surface, enhance stability, and prevent slipping. Beyond performance enhancement, footwear is also vital in load transmission and protecting the foot from potential injuries.
Historically, stud designs have evolved to match playing surfaces:
- Soft-Ground (SG) Boots: Feature longer, occasionally screw-in studs designed for deeper penetration into the grass, which increases traction in wetter conditions by locking into the grass root zone.
- Firm-Ground Circular-Shaped (FGC) Boots (Rounded/Ovoid): Utilize studs that are shorter and more numerous.
- Firm-Ground Blade-Shaped (FGB) Boots (Bladed/Knife/Elongated): Introduced to increase the contact area for linear movements, thereby increasing linear traction.
- Artificial Grass (AG) Boots: Tend to have a larger number of smaller studs placed across the outsole.
What Are the Key Forces Important in Football Boots?
The interaction between the boot and the ground is defined by the forces transmitted, which affect both performance and injury susceptibility.
Traction Force (TF) is the force generated on the shoe-surface interface. This force is important for stability during stance and is considered the most important characteristic of a boot, second to comfort.
Translational Traction Coefficient (TC) is the ratio of horizontal force. Moderate levels of TC are important for acceleration, and change of direction. Excessive force lead to foot fixation which can lead to increased injury risk.
Rotational Resistance is the resistance to twisting movements. Excessive rotation resistance is associated with non-contact torsional injuries seen in anterior cruciate ligament (ACL) tears. Stud shape can influence this force.
Plantar Pressure (PP) is the force the foot experiences within the boot. Cleat outsoles increase ground reaction forces (GRF) at ground contact, which creates zones of localized pressure on the foot. Poor plantar distribution from stud arrangement can lead to overload of the foot bones and can cause stress fractures.
The Propulsion Force (PF) is the component of force from thrust and greater PF results in enhanced forward acceleration.
How Does the Interaction between Boot and Surface Change?
The playing surface has the largest impact on translational traction (TC). Artificial Grass (AG) generally provides higher TC and moment of force (rotational stiffness) compared to Natural Grass (NG). This is due to the tearing mechanism of NG compared to AG. A boot may either hold its position, slide, or tear through the playing surface. Due to the nature of AG, AG rarely tears, while NG under high TC disrupts the root zone acting as a potential injury mitigation mechanism. Boots with only six studs should not be used on AG because they generate considerable impact peaks in traction tests and without surface tearing mechanism, pose increased risk for athletes.
What type of studs improve performance in straight line and cutting on NG and AG surfaces?
When considering only performance, triangle studs generate more Propulsion Force (PF) than Knife Studs (KS) or Blade Studs (BS). This may be an important consideration depending on the position of the athletes if high bursts of acceleration are required. Round studs produce the lowest ground reaction force (GRF), leading to potential loss of traction with acceleration. Blade studs produce the highest Translation Traction Coefficient (TC) force on AG. While round studs appear to have good capability for directional change without excessive force. Blade studs show greater TC forces and contact time, suggesting lower performance in change of direction but more stability. Blade studs on NG show greater TC during medial translation (cross over movements). It is important to note that cross over movements are infrequent and may not provide a benefit in the grand scheme of the game.
Stud Shape Summary
Elliptical Stud- Generate greater peak pressure in the forefoot upper lateral and forefoot center medial, and heel. Risk: increased heel pressure
Knife Studs- Higher peak pressure in the lateral forefoot during cutting movements than triangle studs. Risk: May precipitate more lateral metatarsal injuries.
Rounded Studs- Higher more distributed peak force over forefoot region(Medial and Central forefoot) during running and cutting movements. Risk: calluses, forefoot pain, or metatarsal stress fractures.
Triangle Studs- Smaller peak pressure over the forefoot than rounded studs. Good explosive force and capability for direction change with less risk of medial metatarsal injury compared to rounded studs. Risk: Medial and central forefoot stress.
How do studs effect Biomechanics and Pressure change with different stud patterns?
Stud shapes dictate how force is transmitted in the foot, ankle and knee. Knife stud or bladed studs have higher peak pressure on the lateral foot during cutting and change of direction compared to rounded and triangle studs. Rounded studs have higher peak pressure in the medial and central forefoot and higher heel pressure, leading to lower mid foot pressures and improved distribution of force. This may be important for reducing bone stress injuries; particularly in those athletes that may have history of bone stress injuries.
Cleats with greater rotation traction like bladed stud patterns lead to reduced knee valgus position but increase shear forces, especially in female athletes.
What Is the Difference Between Male and Females with Different Boots?
There is a mechanical disparity between sexes, particularly regarding injury risk and footwear design. Female athletes tear ACL’s at 3x higher rates than males. This link may be associated with neuromuscular control, joint laxity, and anatomical alignment. Soccer footwear is designed based on male users. Females may have a lower sensitivity threshold to traction compared to males. This means high traction footwear may exacerbate female susceptibility to torsional injuries if rotational resistance exceeds ligament capacity. Additionally, females exhibit 19% longer contact time during cutting than males and have a tendency towards posterior lateral loading patterns than males. The center of pressure was 4-14% more posterior and 5-10% more lateral than males. Males tend to generate 40% more peak pressure at the center and medial forefoot during initial cutting compared to females. It appears female athletes have greater knee valgus when wearing elliptical stud shapes, where knee valgus has been considered a strong risk factor for knee injuries.
Additionally, systemic fatigue exacerbates biomechanical differences which increases the injury risk in females. Females under fatigue experience greater medial to lateral center of pressure excursion indicating greater instability during cutting. Fatigue also increases posterolateral peak pressure shift. It appears that systemic fatigue has a greater detrimental effect on female mechanics, than males, seen through increase peak knee valgus, ankle and knee extensor moment, and was more pronounced with bladed cleats. Male athletes on the other hand show decreased knee extensor moment after fatigue, independent of cleat pattern. The increased posterolateral pressure shift and greater mediolateral excursion with bladed cleats produced in females athletes may adversely effect females when fatigued.
What Stud Patterns Result in Increased Risk for Different Types of Injuries?
Injury risk is heavily influenced by the balance between traction needed for performance and excessive resistance that causes foot fixation.
Very aggressive stud patterns like Bladed/Chevron type in the forefoot and hind foot was significantly associated with higher odds of total lower limb injury. This pattern is thought to increase rotational torque raising the risk of lower limb injury via resistance to rotation and foot fixation.
Mildly Aggressive stud patterns on only one end of the boot showed lower odds of total lower extremity injury.
Non-aggressive stud patterns such as Conical/Rounded Studs were not significantly associated with total injury odds.
In the case of overload injuries, increase in medial and rearfoot studs combined with decrease in lateral rearfoot studs was associated with foot overload injuries. This pattern leads to overloading the lateral structure due to supinated rearfoot position. Elongated studs and knife studs showed higher peak pressure on the lateral foot during cutting, which may precipitate lateral metatarsal injuries. Ankle joint make up 43% of all registered injuries. A higher number of studs over the toes was a positive predictor of ankle overload injuries possibly due to excessive traction during maximal plantar flexion. The probability of lower limb injuries significantly increases for players who have been practicing football for 18 years or more. Players aged 23-30 years had a significantly higher incidence of injury compared with those aged 18-22 years.
Stud Pattern Category Pros Cons/Risks
Very Aggressive (VA) / Bladed / Knife Stud (KS) Higher traction generally observed. Stronger stable support. Significantly better grip during medial movement on NG. Potential for explosive takeoff on AG. Significantly higher odds of total injury. Higher peak pressure on the lateral forefoot (LFF), risking lateral metatarsal injury. May adversely affect females when fatigued.
Mildly Aggressive (MA) Significantly lower odds of total overall injury. Lower injury risk for attackers, forwards, goalies Higher injury risk for Defenders
Nonaggressive (NA) / Round Stud (RS) RS provides good directional change ability. RS produces the minimum peak vGRF. No specific performance benefits
Triangle Stud (TS) Shows good explosive force and good direction changing ability. Generated significantly more PF during straight running. N/A
Aggression Category Stud Shape Boot Model Mentioned in Sources
Very Aggressive (VA) / High Traction Bladed / Knife Studs (FGB) 1.Adidas Predator Edge .2 (Bladed cleat, associated with greater rotational traction)
Bladed / Knife Studs (FGB) 2.Nike Mercurial Vapor 14 Elite boot (Firm-Ground Blade-Shaped [FGB])
Soft-Ground (SG) 3.Nike Tiempo Legend 9 Elite boot (SG variant) (Uses longer studs, associated with higher traction)
Mildly Aggressive (MA) / Medium Traction Triangle Studs (TS) 3.Adidas X 15.4 FG
Mildly Aggressive FG
Nonaggressive (NA) FGElliptical Studs 4.Adidas Copa Sense .3 (Elliptical cleat, associated with lower available traction)
Rounded/Circular Studs (FGC) 5.Nike Hypervenom I FG (Round Stud [RS])
Rounded/Circular Studs (FGC/AG) 6.Nike Tiempo Legend 9 Elite boot (FGC and AG variants) (FGC is typically circular)
Nonaggressive (NA) TF Turf (TF) 7.Nike Phantom GT2 Pro TF
Recommendations for Stud Selection
- Avoid Very Aggressive (VA) Patterns for Injury Mitigation: EPL data strongly suggests that VA stud patterns should be avoided due to significantly increased injury odds. Mildly Aggressive (MA) patterns are associated with significantly lower injury odds.
- Match Boot to Surface: Boots with longer or irregularly shaped studs often result in larger levels of traction on both NG and AG. Boots with only six studs are contraindicated for AG.
- Consider Female Biomechanics and Fatigue: Footwear products for female athletes should address female-specific mechanics. High rotational traction cleats (bladed) may detrimentally affect female knee mechanics under fatigue. There is a suggested need to improve lateral and posterior stud arrangement for female-informed designs.
- Age and Practice History: Players with 18 years or more of practice have a higher probability of injury. Older players prone to ankle overuse injuries should be cautious of boots with a high number of studs under the toes.
- Forefoot and Rearfoot Load Balancing: To mitigate foot overload injuries, players should avoid combinations where the number of medial rearfoot studs is higher than the number of lateral rearfoot studs
My Professional Opinion
Performance optimization is of high concern for athletes. However, injuries can influence an athlete’s ability to participate, develop skills, and progress in the sport. Ultimately, the question becomes, would you rather slip on a defensive or offensive maneuver, or would you rather maintain traction and risk injury? With the growing high stakes athletes face, and the increased exposure to playing surfaces that have little to no give, there appears to be an unnecessary focus on aggressive cleats. In writing this blog, I’ve revisited my own cleats, and lean towards a less aggressive, balanced, rounded or triangular studded cleat pattern which strikes a balance between performance and reduced injury risk. More specifically, I would purchase an FG non-aggressive cleat for both NG and AG surfaces, as there appears to be a benefit compared to AG-specific boots. An athlete’s weight may also alter the type of cleat that would be the most beneficial for them. Heavier athletes may have greater penetration in NG but also greater NG tearing under forceful or explosive movements. Stronger athletes may require greater NG traction forces to avoid slipping, especially if they are lighter and their cleat penetration into NG is less than their heavier counterparts. When it comes to AG, foot fixation is BAD. AG does not give or tear, so a less aggressive cleat would reduce injury risk with hard cutting and twisting. In this case, heavier athletes may benefit from a less aggressive stud pattern. Stronger, more explosive athletes on AG may also benefit from a less aggressive stud pattern, as there is sufficient traction with most rounded and triangle stud patterns, with less foot fixation compared to knife and bladed stud patterns. If you find yourself slipping on NG or AG frequently, a more aggressive stud pattern may be warranted; however, rarely do most athletes slip, especially on AG with FG boots. The cost of injury, in my opinion, is not worth the minimal performance benefit and street cred of excessively aggressive knife or bladed cleats. When selecting cleats, consider your injury history. I recommend sipping into a less aggressive, rounded or triangular stud pattern. This will give you the peace of mind that you’ll maintain traction and minimize foot fixation so you can focus on skill development and soccer IQ.
Author:
Radek Wiechecki, MScPT, BScKin, BScBiol
If you have any questions, comments, or concerns, we’d love to hear from you. Email us at: info@thelabrehabandperformance.com.
References:
- Castillo-Domínguez, A., Torrontegui-Duarte, M., Páez-Moguer, J., Gómez-del-Pino, Á., Cervera-Garvi, P., Mainer-Pardos, E., … & García-Romero, J. (2022). The influence of stud characteristics of football boots regarding player injuries. International Journal of Environmental Research and Public Health, 20(1), 720.
- Pescatore, S. M., DeShazo, S. J., & Weiss, W. M. (2025). Effects of Soccer Cleat Stud Patterns Worn Versus Lower Extremity Injuries in the English Premier League. Orthopaedic Journal of Sports Medicine, 13(7), 23259671251353762.
- Karolidis, E., & Hahn, M. E. (2023). Changes in knee mechanics with systemic fatigue and soccer cleat stud shape appear to differ by sex. Footwear Science, 15(sup1), S199-S200.
- Karolidis, E., Denton, A., & Hahn, M. (2025). Effect of football cleat stud shape, sex and fatigue state on plantar loading during lateral cutting. BMJ Open Sport & Exercise Medicine, 11(2)
- Lv, X., He, Y., Sun, D., Baker, J. S., Xuan, R., & Gu, Y. (2020). Effect of stud shape on lower limb kinetics during football-related movements. Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, 234(1), 3-10..
- Loud, D., Grimshaw, P., Kelso, R., & Robertson, W. S. (2024). Effect of soccer boot outsole configuration on translational traction across both natural and artificial playing surfaces. Orthopaedic Journal of Sports Medicine, 12(8), 23259671241259823