Catalyst Performance · Youth Athlete · Injury-Risk & Performance Report

Beckam Underwood — Performance Profile

Soccer · Force-plate screen · Benchmarked vs same-age (9–10U) boys

Screen date: Jan 29, 2024

Age at test 9

Bodyweight 39.8 kg (88 lb)

Platform: VALD ForceDecks (CMJ + Squat Jump)

The one-line read

At 9, Beckam was a solid-to-strong jumper for his age with beautifully symmetrical push-off — the engine and the takeoff were genuinely good. The one thing to refine was on the way down: he absorbed noticeably more landing force on the right than the left. Push is even; landing is not — and uneven landing is exactly where youth knee/ACL risk hides. Easy to train, especially at his age.

Performance signature — best of 5 jump trials · Jan 2024

19.8 cm

Countermovement Jump

Good for a 9-yr-old

36.7 W/kg

Relative Peak Power

Strong engine for age

1,459 W

Peak Power

Explosive

~4%

Push-off Asymmetry (L/R)

Excellent — balanced

+23%

Landing Force Asymmetry

Priority · right loads more

~0.21

Reactive Strength (RSImod)

Developing — normal at 9

Athlete profile

Name / sportBeckam Underwood · Soccer

Age / DOBNow 12 · tested at 9 · DOB Jun 10, 2014

ScreenVALD ForceDecks — CMJ (5 trials) + Squat Jump

Bodyweight at test39.8 kg (≈88 lb)

CapturedJump power, push-off & landing symmetry

Not captured (do on re-test)Single-leg symmetry · drop jump · hip/hamstring strength

The three findings

Even out the landing — the one real flag
Push-off is symmetric (~4%), but on landing the right leg absorbs ~18–23% more force than the left. It's a deceleration/control pattern, not a power gap — and it's the most valuable thing to train because uneven landing is a leading, modifiable youth ACL risk factor.

Build reactive (elastic) strength
His ground-contact time was long (~1.0 s) and reactive-strength index modest (~0.21) — completely normal at 9. Simple, fun plyometric progressions turn his good raw power into quick, springy, resilient movement.

Protect what's already good
Real strengths to keep: jump height and power above age-typical, and symmetric force production through the drive. Keep loading the engine while the landing catches up.

Page 1 of 5 — Injury-Risk & Performance Report for Beckam Underwood. Confidential (minor). A performance & movement evaluation, not a medical diagnosis. Captured on VALD ForceDecks by the Catalyst Performance team · The Studio by Catalyst.

Power & Force — what the plates measured

Beckam stood on dual force plates sampling 1,000×/second through a jump battery. Here's how, at 9, he produced and absorbed force. Values are the best of 5 maximal countermovement-jump trials.

A real engine for his age. His countermovement jump (19.8 cm) and relative power (36.7 W/kg) sit at the upper end of typical for a 9-year-old boy, with a peak power of ~1,460 W. The raw athletic ingredients — strength to drive off the ground — were clearly there.

Jump battery

Metric	Result (best)	What it tells us
Jump Height (CMJ)	19.8 cm · 7.8″	Explosive lower-body power with a counter-movement
Peak Power	1,459 W	Total power produced on the drive up
Relative Peak Power	36.7 W/kg	Power per kg — the fairest cross-athlete comparison
Concentric Mean Power	19.5 W/kg	Sustained power through the push, not just the peak
Counter-movement Depth	~33 cm	A deep, full dip into the jump
Squat Jump	captured	Push from a dead stop (force/power recorded)

Reactive (elastic) power — his clearest upside

Reactive Strength (RSI-modified)~0.21 — developing

RSImod = how much height he gets per unit of time on the ground. ~0.21 with a long ground-contact (~1.0 s) means he's powerful but not yet springy — completely age-appropriate at 9, and the single most trainable quality through plyometrics.

Ground-contact / contraction time~1.0 s

A long, deliberate jump action. As he matures, shortening this (faster, reactive contacts) is where a big chunk of athletic "pop" comes from.

How to read these. A 9-year-old's force-plate numbers move fast with growth and aren't yet locked in. We treat them as a snapshot of a developing athlete — strong raw power, reactive qualities still to come — not a fixed verdict.

Page 2 of 5. Each value is the best of multiple maximal trials. VALD ForceDecks, Jan 2024. © Catalyst Performance.

Symmetry & injury risk — left vs right

How evenly the two legs shared the work. Target gap is under 10%; 10–15% is worth watching; over 15% is a priority. This is where his one flag lives.

Push-off force — driving up (CMJ)~4% — balanced

Through the powerful, bilateral drive of the jump the legs were well matched (concentric force 4.7%, takeoff peak force 4.1%). His force production is symmetric — a genuine strength.

Landing force — impact absorption+23% (right absorbs more)

Coming down, the right leg took ~23% more peak force and ~19% more landing impulse than the left — he quietly off-loads the left on landing. This is the headline finding.

Braking (eccentric) force — slowing the dip~10–12% (right does more)

The same side-bias shows up, milder, in braking (eccentric mean force 10%). The pattern is consistent: push is even, deceleration is right-dominant.

The headline. Beckam's symmetry is good where he produces force (push-off ~4%) but breaks down where he absorbs it — landing is ~19–23% right-dominant, with the left leg off-loaded. Uneven landing & deceleration is one of the most established modifiable risk factors for non-contact knee/ACL injury. At 9 (and now 12) it's highly trainable with landing & single-leg work — catching it early is exactly the point of screening.

Where he sits vs the thresholds

Marker	Target	Beckam (2024)	Read
Push-off asymmetry	< 10%	~4%	On target
Landing asymmetry	< 10%	~19–23%	Priority
Braking asymmetry	< 10%	~10–12%	Monitor
Single-leg symmetry (LSI)	> 90%	not tested	capture on re-test
Hamstring / groin strength	balanced	not tested	add DynaMo

Landing rate-of-force-development asymmetries were higher still (~25–35%) but are noisy in young athletes, so we lead with the stable force & impulse measures above.

EVIDENCE BASE Inter-limb asymmetry & injury/performance (Bishop et al.; Read et al., youth) · limb-symmetry & return-to-sport (Grindem et al., 2016) · dynamic knee valgus & landing mechanics in non-contact ACL (Hewett et al.) · youth physical development model (Lloyd & Oliver). Reference research applied to Beckam's data — not individual medical advice.

Page 3 of 5. Asymmetries averaged across trials. A performance & movement evaluation, not a medical diagnosis. © Catalyst Performance.

Benchmarks — Beckam (age 9) vs same-age boys

His 2024 numbers against reference bands for a ~9–10U male athlete — Developing → On-track for age → Strong for age. The marker (▲) is Beckam at 9. Bands are youth reference ranges, not pass/fail lines.

Countermovement Jump — explosive power19.8 cm · strong for age

Developing <16 cmOn-track 16–21Strong 21+ cm

Relative Peak Power — power per kg36.7 W/kg · on-track

Developing <30On-track 30–40Strong 40+ W/kg

Reactive Strength (RSImod) — elastic / spring~0.21 · developing

Developing <0.25On-track 0.25–0.40Strong 0.40+

Push-off Asymmetry (L vs R) — lower is better~4% · on target

On target <10%Monitor 10–15Priority 15%+

Landing Asymmetry (L vs R) — lower is better~19–23% · priority

On target <10%Monitor 10–15Priority 15%+

Where he ranked. At 9, Beckam was on-track to strong for his age on the power metrics with excellent push-off balance — a good athletic base. The two levers to move him up are reactive strength and, above all, landing symmetry — and the second one is also his injury-risk priority. The same training fixes both.

Body focus map

1 · Landing / deceleration chain Primary

Found: right leg absorbs ~19–23% more landing force; left off-loaded; push-off itself is even. Why: uneven landing concentrates impact and is tied to non-contact knee/ACL risk; the off-loaded side often hides a control or confidence deficit. Train: double- & single-leg landing mechanics, eccentric/decel control, hop symmetry, glute/quad control on the left.

2 · Reactive strength (both) Secondary

Found: long ground contact (~1.0 s), modest RSImod (~0.21). Why: springy, quick contacts protect joints and add speed — and they're age-appropriate to build now. Train: fun plyometric progression — pogos → hops → low bounds.

+ Not yet tested re-test

Add at his next screen: single-leg jump (true per-leg LSI), drop jump (reactive strength), and DynaMo strength (hip/groin adductors + hamstring:quad) — the pieces that complete a soccer ACL/groin picture.

Page 4 of 5. Benchmarks vs ~9–10U male reference bands (his age at test) + body focus map. Reference ranges, not pass/fail lines. © Catalyst Performance.

The plan — and what to do next

A phased, age-appropriate plan built around his one flag (landing) and his upside (reactive strength) — plus the re-screen that turns this baseline into a live progress track.

Phase 1 — Land it (weeks 1–4)

Symmetry & control

Landing mechanics — soft, symmetrical two-foot landings; teach even weight through both legs (cue the left to "take its share").
Single-leg control — balance & single-leg landings, slightly biased to the left to even out the off-loading.
Glute & quad control — bodyweight strength so the left can confidently absorb load.

Phase 2 — Build & balance (weeks 4–10)

Strength & spring

Age-appropriate strength — split squats, step-ups, hinge patterns; keep the engine growing.
Plyometric progression — pogos → hops → low bounds to shorten ground contact and lift reactive strength.
Re-test landing symmetry at week 8.

Phase 3 — Express it (weeks 10–12+)

Soccer-specific

Cutting & deceleration — apply even landings to change-of-direction.
Full re-screen — CMJ + single-leg + drop jump (+ DynaMo) vs this baseline.

Growth & load

Now 12, he may be in or near a growth spurt — watch training/match volume and any knee or heel soreness, and keep calves & quads mobile. Strength scales to him.

Recovery basics

Sleep is the #1 lever at his age (9–11 hrs). Simple post-play mobility, hydration & fuel; the recovery lounge keeps him fresh through a busy season.

Next step — re-screen Beckam. This report is his age-9 baseline. A ~15-minute force-plate re-screen (adding single-leg, drop jump and DynaMo strength) shows where the 12-year-old version stands today, whether the landing asymmetry has resolved, and gives him a true side-by-side progress story. His data syncs automatically and this report updates.

Measure the change

2024

Baseline (age 9) — this report

Now

Re-screen at 12 — current status

+10–12 wk

Re-test landing & symmetry

Page 5 of 5 — Performance Report for Beckam Underwood. Prepared by the Catalyst Performance team · The Studio by Catalyst, Rancho Bernardo · catalystperformancesd.com. A performance & movement evaluation, not a medical diagnosis.