Catalyst Physical Therapy & Wellness · Force-Plate Screen

Ewelina Rogoz — Return-to-Sport Screen

Female · Age 32 (DOB 04 Feb 1994) · Tested 10 Sep 2026 · Bodyweight 65.3 kg (144 lb)
VALD ForceDecks battery · Focus: recurrent calf strain — running & volleyball

Confidential — prepared for Kyle & Brian Wilson, MPT

Why she's here. Ewelina keeps re-straining her calves with running and volleyball. This force-plate screen looks past raw jump numbers to the reactive (spring-like) and landing qualities that a calf actually has to deliver in those two sports. The headline: her power base is good and her legs are symmetric in a basic jump — but the specific calf qualities that running and volleyball punish are underdeveloped. That gap is a plausible mechanism for why the injury keeps returning, and it points to clear, trainable targets rather than "rest and hope."

Screen snapshot — six domains that matter for her calves

Power base

✓ Good

CMJ 26.0 cm, 42.8 W/kg — solid for a recreational woman her age.

Limb symmetry (push)

✓ Passes

Single-leg jump 98% symmetric — clears the standard ≥90% return-to-sport bar.

Reactive calf spring

● Develop

Low reactive strength & long ground contact — the calf-Achilles isn't springing.

Reactive symmetry

▲ Monitor

Left calf ~12% slower on the reactive hop — asymmetry hides in quality, not height.

Landing / deceleration

● Develop

Landing load 19–27% lopsided and inconsistent — key for volleyball.

Direct calf strength

◦ Not measured

Plantarflexor strength/endurance wasn't isolated this session — recommend adding it.

Body map — where the flags land

✓ Green good / passes ! Amber monitor ! Red develop ? Grey not measured

The calf story — what the numbers converge on

Three independent measures all point the same way: her calf-Achilles unit behaves like a soft spring, not a stiff one.

Signal	Ewelina	Working reference	Read
Elastic contributionCountermovement vs squat jump (EUR)	+3%26.0 vs 25.4 cm	> +10%	A healthy stretch-shortening cycle "free-lifts" the jump ~10–20%. Hers adds almost nothing — the tendon spring isn't contributing, so muscle does the work.
Reactive strength (RSI)Drop jump	0.81contact 0.33 s	≈ 1.0–1.5+	Low, with a long ground contact (>0.30 s = compliant). She lands and "sinks" rather than rebounding — more time under load for the calf.
Rebound RSIRepeat countermovement jump	1.32contact 0.32 s	higher w/ shorter contact	Same pattern on a second reactive test — modest spring, slow contact.

Why this drives recurrent calf strain. Running is thousands of fast calf loading cycles; volleyball is repeated jump-landings. When the tendon isn't sharing the load as an efficient spring, the calf muscle absorbs and returns more energy on every stride and landing. Over a run or a match that's a large cumulative overload on tissue whose capacity hasn't been built to match — exactly the setup for a strain that clears with rest, then returns when volume climbs again. The fix is capacity, not just recovery: make the spring stiffer and the calf stronger.

Return to sport · Running — what we look at to call a runner good

🏃 Running readiness

Not yet — build reactive capacity first

What we check & why	Target	Ewelina	Status
Reactive strength (RSI)Running is a repetitive spring — this is the #1 quality	≈1.0–1.5+	0.81	Develop
Elastic contribution (EUR)Tendon doing its share of the work	>+10%	+3%	Develop
Ground contact timeStiff, fast calf vs soft/slow	<0.25 s	0.33 s	Monitor
Single-leg reactive symmetryBoth calves spring equally (hop contact time)	L≈R (<10%)	L 12% slower	Monitor
Single-leg push symmetryNo side is skipping propulsion	LSI ≥90%	98%	Pass
Plantarflexor capacity / enduranceCan the calf itself last the mileage	direct test	—	Add test

Bottom line for running: her legs are even and she has power — but the reactive/elastic engine that protects a runner's calf is under target, and her calf endurance wasn't directly tested. Return should ride behind a reactive-strength and calf-capacity build, with running volume progressed against symptoms rather than pushed on feel.

Return to sport · Volleyball — what we look at to clear a jumper/lander

🏐 Volleyball readiness

Not yet — landing control is the gap

What we check & why	Target	Ewelina	Status
Jump height / powerApproach & block ceiling	age-solid	26–28 cm	Good
Landing-force symmetryRepeated landings must share load — top calf/ankle risk	<10–15%	19–27%	Develop
Landing consistencySame control every rep, not just once	stable	varies to 40%	Develop
Reactive / repeat jump (RSI)Block-jump, jump again — quick re-jump	higher, short contact	1.32 / 0.32 s	Monitor
Landing stabilisation (single leg)Control on one leg after a hop	quick & even	R slower to settle	Monitor
Single-leg push symmetryEven off either leg for approach	LSI ≥90%	98%	Pass

Bottom line for volleyball: the power to play is there, but she lands lopsided and inconsistently — one leg (and calf) takes an outsized, unpredictable share of each landing. In a sport built on repeated jump-landings that's both a re-injury risk and a performance leak. Landing/deceleration retraining is the priority before full volleyball load.

Symmetry & landing detail

Measure	Left	Right	Asymmetry	Read
Single-leg jump heightpropulsion	12.6 cm	12.9 cm	2–3%	Even — passes ≥90% LSI
Reactive hop — contact timecalf spring speed (lower=better)	0.298 s	0.261 s	L 12% slower	Left calf lags
Single-leg landing stabilisationtime to settle (lower=better)	0.56 s	0.85 s	R slower	Right control
Two-leg landing force (CMJ)load sharing on landing	mean 27% lopsided (up to 40%)		>15%	Uneven & variable
Two-leg landing force (drop jump)load sharing, higher speed	19% lopsided		>15%	Uneven
Push-off impulse (CMJ)load sharing on takeoff	10%		~10%	Borderline

The pattern that matters: she is symmetric when pushing off (jump height even) but asymmetric and inconsistent when absorbing (landing). Calf and Achilles injuries are overwhelmingly loading/deceleration injuries — so a screen that only looked at jump height would call her "even" and miss the real issue. The absorbing side of her movement is where the work is.

Full battery — 10 Sep 2026

Test	Key result	Reference (recreational ♀)	Note
CMJ countermovement jump	26.0 cm · 42.8 W/kg · mRSI 0.30	~20–27 cm · 40–50 W/kg	Solid power base
SJ squat jump	25.4 cm	—	vs CMJ → elastic gain only +3%
ABCMJ arm-swing jump	27.9 cm	+10–20% over CMJ	Arm-swing adds only +7%
DJ drop jump	RSI 0.81 · contact 0.33 s	RSI ~1.0–1.5+	Low reactive strength
CMRJ repeat rebound jump	RSI 1.32 · contact 0.32 s	higher, shorter contact	Modest spring
SQT isometric squat	peak 809 N (~1.26× BW)	—	Max lower-limb force modest
SLJ single-leg jump	L 12.6 / R 12.9 cm · LSI 98%	LSI ≥90%	Propulsion symmetric
SLHAR single-leg hop & return	contact L 0.30 / R 0.26 s	L≈R	Left calf reactively slower

Talking points for Kyle

✓ Good to go / strengths — lead with these

Real power base. Her jump height and relative power are solid for a recreational woman her age — you're not chasing raw strength or "getting stronger" as the headline.
Symmetric push-off. Single-leg jump is 98% even — she clears the classic ≥90% limb-symmetry bar for propulsion. Neither leg is avoiding work when driving off the ground.
No red-flag weakness or gross deficit — this is a quality-and-capacity problem, not a "can't produce force" problem, which is an encouraging starting point.

● Priorities — what to actually train (in order)

Build the calf spring (reactive strength). Low RSI, minimal elastic contribution, long ground contacts all say the same thing. Progress pogos → line/box hops → skips, cueing short, quiet ground contact; pair with heavy-slow & isometric calf-raise work for tendon stiffness. This is the central lever against recurrence.
Retrain landing / deceleration. Landing load is 19–27% lopsided and inconsistent. Drop-landings, single-leg landing holds, decelerate-and-stick drills — build even, repeatable absorption. Highest priority for the volleyball side.
Even up the reactive sides. Left calf is ~12% slower to spring and the right is slower to stabilise a landing. Unilateral reactive and landing work to close both gaps.
Raise calf strength & endurance ceiling. Max lower-limb force is modest and endurance is untested — a stronger, more fatigue-resistant calf simply tolerates more running/jumping before it fails.
Progress load against symptoms. Recurrent strain = demand outran capacity. Step running mileage and jump volume up gradually and watch symptoms, rather than returning at prior volume on how she feels day-of.

◦ What we couldn't measure — recommend before full clearance

Direct calf strength & endurance. The force-plate battery measures the calf indirectly through jumps. A single-leg calf-raise-to-fatigue test (reps L vs R) and/or DynaMo plantarflexion would put a real number on the injured tissue itself — strongly recommended for a recurrent calf.
No prior VALD session = no trend yet. This is her baseline. A short-interval re-test (like the pros do — test often, not on a fixed calendar) would show whether reactive strength and landing symmetry are actually moving, and is the cleanest objective green-light to progress.

Prepared by Catalyst PerformanceData: VALD ForceDecksTest 10 Sep 2026

What this screen is — and isn't. This is a movement/performance screen to guide training and rehab decisions and give the treating clinician objective talking points — it is not a medical diagnosis or a guarantee against injury. The reference ranges and symmetry/reactive thresholds shown are working clinical conventions and training targets, not validated injury predictors; the evidence linking any single force-plate cutoff to injury is mixed. Numbers here explain a plausible mechanism and point to trainable targets — they should be read alongside Kyle's hands-on assessment, her symptom history, and clinical judgement, not in place of them. Confidential — intended only for Ewelina's care team.