Position Group | Mean Con Power (W/kg) | Mean Ecc Power (W/kg) | Mean Con RFD (100ms) | Mean Ecc RFD |
|---|---|---|---|---|
Attacker | 27.7 | 7.9 | 3,901 | 5,421 |
Defender | 25.2 | 6.9 | 1,997 | 5,386 |
Goalkeeper | 21.6 | 6.9 | 3,668 | 6,370 |
Midfield | 23.2 | 8.0 | 3,259 | 5,097 |
UO Womens Soccer Power Profiles
Zak Kindl, MS, CPSS
Introduction & Selected Metrics
The athletic demands of women’s soccer represent a unique challenge to the athlete and sport science unit. Specifically the lower body power demands which requires the ability to produce and absorb high forces over a short period. The female athlete may be especially susceptible to injury, specifically when a mismatch or overload of these demands occurs. The goal of this case study is to identify metrics that could provide insight into the lower body power characteristics of different players and position groups using, validated, reliable and repeatable measures from the CMJ test. These metrics will be used to provide strength and conditioning staff with suggested interventions (Bishop et al. 2022),(Merrigan et al. 2021).
The selected metrics are as follows
- Relative Peak Power (W/kg)
Peak power represents the optimal combination of force and velocity (P = F × v) during the concentric (propulsion) phase of the CMJ, typically occurring at approximately 60-70% of the push-off phase (Philpott et al. 2021). Normalizing to body mass (W/kg) allows comparison across athletes of different sizes and positions. Peak power is correlated with sprint performance, jump height, and change of direction ability in soccer players.
- Peak Relative Eccentric Power (W/kg)
Eccentric peak power during the braking phase reflects an athlete’s capacity to absorb and control forces during deceleration (Nishiumi et al. 2023). This metric is crucial for landing mechanics, change of direction ability, deceleration from high-speed running, and absorbing contact during physical play. (Philpott et al. 2021)
- Concentric RFD 100m/s
Rate of Force Development during the first 100 milliseconds of the concentric phase quantifies early-phase explosive strength (Martinopoulou et al. 2022). Since most sport actions occur in under 250ms, RFD at short time windows better reflects functional explosive capacity than peak force alone (Merrigan et al. 2021). High RFD is essential for rapid accelerations, first-step quickness, and reactive movements common in soccer.
- Eccentric RFD
Eccentric RFD quantifies how rapidly an athlete can develop braking forces during the deceleration phase of the CMJ (Nishiumi et al. 2023). This metric reflects reactive stiffness and neuromuscular control during the stretch-shortening cycle. High eccentric RFD is associated with superior change of direction performance, effective landing mechanics, and reduced injury risk during high-velocity deceleration tasks that can commonly result in injury.
Figure 1: CMJ force-time curve showing the temporal location of key performance metrics highlighted
NSCA, Essentials of Sport Science, 2021
Summary Values
Position Groups Comparisson
Values are scaled to a Z-score value
A value of 0 represents the average values by position group, +/- values represent standard deviations above or below the average.
The trend line indicates the direction the group is trending relative to the linear relationship between RFD and relative peak power (ex. a position group is trending towards high power and slow RFD)
Concentric RFD to Relative Power
Eccentric RFD to Relative Power
Individual Player Values
Athlete | Position | Con Power | Ecc Power | Con RFD | Ecc RFD |
|---|---|---|---|---|---|
13 | Attacker | 23.4 | 7.6 | 4,023 | 3,905 |
8 | Attacker | 29.0 | 6.6 | 2,490 | 5,421 |
4 | Attacker | 28.6 | 8.9 | 3,743 | 5,634 |
6 | Attacker | 29.7 | 8.4 | 5,347 | 6,722 |
5 | Defender | 22.3 | 7.2 | 500 | 4,937 |
16 | Defender | 23.2 | 7.8 | 847 | 3,271 |
1 | Defender | 23.3 | 5.1 | 1,460 | 3,597 |
18 | Defender | 24.7 | 7.7 | 3,207 | 7,429 |
17 | Defender | 30.5 | 6.2 | 1,520 | 6,944 |
9 | Defender | 27.2 | 7.5 | 4,447 | 6,138 |
7 | Goalkeeper | 21.4 | 5.9 | 1,277 | 7,819 |
2 | Goalkeeper | 21.9 | 7.8 | 4,000 | 4,009 |
12 | Goalkeeper | 20.9 | 6.7 | 4,740 | 7,405 |
11 | Goalkeeper | 22.3 | 7.3 | 4,653 | 6,246 |
14 | Midfield | 21.5 | 7.0 | 2,577 | 6,666 |
15 | Midfield | 21.0 | 9.2 | 2,917 | 3,922 |
10 | Midfield | 23.4 | 7.8 | 3,520 | 4,070 |
3 | Midfield | 25.0 | 8.3 | 3,407 | 5,210 |
19 | Midfield | 25.3 | 7.8 | 3,877 | 5,621 |
Exercise Recommendations
Common Deficiencies:
Low Eccentric Power Capability
Low Breaking Force Capability
Low Power Production in Defensive Groups
Recommendations:
Work on concentric eccentric imbalance with both fast and slow eccentric work while continuing to improve concentric RFD and peak power with weighted jumps and near 1RM lifts complimented with plyometric components for reactivity.
Strength:
Eccentric barbell back squat with high load > 1RM
Single leg dumbbell squat with emphasis on eccentric tempo
Nordic curls with emphasis on control through full ROM, utilize variations if needed
Loaded barbell jumps with light to moderate load with cues to move bar fast
Plyo:
Depth drop jumps with cues to reduce ground contact time
Band assisted jumps double or single leg to emphasis over-speed familiarity
Future Analysis
With added data, performance testing and repeat testing future analysis options could include:
Further exploration of other jump tests to create detail eccentric concentric power and force ratios.
Exploration of L/R asymmetries and determination of threshold of asymetry concern.
Analysis of raw force time data to identify different jumping strategies win force time curve profiles.
Detailed force velocity profile measuring force across various velocities to determine peak force velocity relationship.
References
Bishop, Chris, Anthony Turner, Matt Jordan, John Harry, Irineu Loturco, Jason Lake, and Paul Comfort. 2022. “A Framework to Guide Practitioners for Selecting Metrics During the Countermovement and Drop Jump Tests.” Strength & Conditioning Journal 44 (4): 95–103. https://doi.org/10.1519/SSC.0000000000000677.
Martinopoulou, Klimentini, Olyvia Donti, William A. Sands, Gerasimos Terzis, and Gregory C. Bogdanis. 2022. “Evaluation of the Isometric and Dynamic Rates of Force Development in Multi-Joint Muscle Actions.” Journal of Human Kinetics 81: 135–48. https://doi.org/10.2478/hukin-2021-0130.
Merrigan, Justin J., Jason D. Stone, W. Guy Hornsby, and Joshua A. Hagen. 2021. “Identifying Reliable and Relatable Force–Time Metrics in Athletes—Considerations for the Isometric Mid-Thigh Pull and Countermovement Jump.” Sports 9 (1): 4. https://doi.org/10.3390/sports9010004.
Nishiumi, Daichi, Takuya Nishioka, Hiromi Saito, Takanori Kurokawa, and Norikazu Hirose. 2023. “Associations of Eccentric Force Variables During Jumping and Eccentric Lower-Limb Strength with Vertical Jump Performance: A Systematic Review.” PLOS ONE 18 (8): e0289631. https://doi.org/10.1371/journal.pone.0289631.
Philpott, Lydia Kate, Stephanie E. Forrester, Katherine Aj Van Lopik, Steven Hayward, Paul P. Conway, and Andrew A. West. 2021. “Countermovement Jump Performance in Elite Male and Female Sprinters and High Jumpers.” Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 235 (2): 131–38. https://doi.org/10.1177/1754337120971436.