Sprinting:
Sprinting involves creating forces to project the body horizontally, that can reach speeds over 10m/s, and can reach up to 7-9 times body weight in just 90-110ms. To handle these forces, athletes need to adopt efficient techniques to redirect these outputs. Muscular strength and stiff tendons are qualities we must improve to handle the demands of the sprinting. A high-level of neuromuscular control is also required to maintain optimal technique and positions.
Because of these demands, sprint related injuries occur due to deficits in tissue capacity, poor running technique, or discrepancies in strength from left to right.
Two common injuries amongst sprinters are Achilles tendinopathy (AT) and hamstring injuries (HSI).
After injury, returning too quickly (or without a structured plan), significantly increases the risk of
reinjury. This blog outlines considerations for a safe return to maximal velocity-sprinting following these injuries.
Achilles Tendinopathy:
Achilles Tendinopathy is an overuse injury characterised by pain and thickening along the achilles tendon (AT), Typically developed by repeated loading that exceeds the tendon’s capacity.
During sprinting, the AT functions as a high-speed spring:
- Storing and releasing energy during ground contact
- Needs to tolerate and transfer large forces in 90-100ms
- Plays a major role in both the acceleration phase in maintaining a stiff ankle and maximal velocity mechanics.
A well-designed progressive loading plan is essential in rehabilitation.
Return to Sprinting Considerations:
- Restoring ankle stiffness and compliance through prescribed plyometrics and heavy resistance training.
- Develop calf capacity with variations of seated and standing calf exercises and progressions.
- Track and scale intensity by monitoring the number of ground contacts in sessions and gradually increasing intensities as tolerated.
- Use criteria based progressions that reflect force outputs, reactive strength metrics, symptom response, movement quality and athlete confidence.
Hamstring Injuries:
Hamstring injuries (HSI) are another common sprinting injury. Contributing factors include
- Insufficient eccentric strength
- Poor lumbopelvic (hip/core) control
- Low ankle stiffness
- Suboptimal sprint mechanics.
Most hamstring injuries occur during late swing phase at maximal velocity, where the hamstring contracts eccentrically to decelerate the leg and prepare for ground contact. This combination of hip flexion and knee extension at maximal velocity places the hamstring in a vulnerable lengthened position.
Return to Sprinting Considerations
- Rebuild maximal hamstring isometric strength.
- Progressing to heavy eccentric loading through knee flexion and hip extension exercises.
- Introduce Rate of Force (RFD) and velocity-based work, such as band-resisted movements or fast eccentrics.
- Address lumbopelvic control, as excess anterior pelvic tilt increases hamstring length and strain during sprinting.
- Use sprint programming to gradually expose the hamstring to maximal velocity in a controlled progression.
Criteria and Benchmarks:
Objective testing helps determine the athletes readiness for progressions. Eliminating guesswork and reducing reinjury risk. Below address the common assessments that we perform here at The Injury Clinic and normative values provided by VALDHub in Elite Track and Field Athletes.
Achilles:
| Assessment type | Male | Female |
| Single Leg Seated Calf Isometric Test | 1.8-2 x Body Weight
Force at 100ms >80% of Max Force |
1.8-2 x Body Weight
Force at 100ms >80% of Max Force |
| Run-Specific Ankle Isometric Push | >4 x Body Weight
Force at 100ms >80% of Max Force |
>3.5 x BW
Force at 100ms >80% of Max Force |
| Single Leg Hop Test | RSI = >1.0m/s
GCT = <200ms |
RSI = >1.0m/s
GCT = <200ms |
| 30cm Drop Jump | RSI = >3.8m/s
GCT = >140ms |
RSI = >3.0m/s
GCT = >140ms |
RSI = Reactive Strength Index
GCT = Ground Contact Time
Hamstring:
| Assessment type | Male | Female |
| Run-Specific Hip Isometric Push | 2.2 – 2.3 x System Weight | 1.95 – 2.0 x System Weight |
| Handheld Dyno 45deg Supine Knee Flexion | 248 – 304N | 248 – 304N |
| Handheld Dyno 90deg Supine Knee Flexion | 174 – 200N | 174 – 200N |
System Weight = Weighing position prior to testing.
THE INJURY CLINIC OFFERS SERVICES INCLUSIVE OF:
PHYSIOTHERAPY: Sports Physiotherapy; Musculoskeletal Physiotherapy; Women’s Health Physiotherapy; Running Analysis; Return to Run Programs
STRENGTH TRAINING: Injury Management; Performance Enhancement; Online Coaching; Return to Sprint Programs
DIETETICS: Sports Dietetics; Race Nutrition and Hydration plans
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