Kaya Johnson

1 · Executive Summary

This is Kaya's second-ever VALD session, tested 3.5 months after her February 2026 baseline. The 20 May 2026 session was her most comprehensive battery yet (7 jump types: CMJ, CMRJ, SJ, LSJ, ABCMJ, SLJ, SLHAR) — an excellent dataset to characterize her movement profile.

The good news — power output is genuinely impressive for her age:

• CMJ jump height 26.0 cm at age 14.3 is well above the 14U female norm (~22 cm). Held steady from Feb (25.9 cm) while bodyweight grew +2.1 kg.
• Peak power /BM 43.7 W/kg, up 6% — power production is growing faster than bodyweight, which is the ideal trajectory.
• RSI-Modified up 11% (0.44 → 0.49) — reactive strength is developing well.
• Contraction time tightened (0.73 → 0.61 s) — she is now generating output 16% faster.

An unusual movement signal — SJ exceeds CMJ:

• Squat Jump (29.3 cm) is HIGHER than CMJ (26.0 cm). This is the opposite of the typical pattern — CMJ should benefit from the stretch-shortening cycle and exceed SJ by 2–4 cm.
• Loaded Squat Jump (with ~4.5 kg) hit 30.5 cm — even with added load, the static-start jump beats her bilateral CMJ. Concentric strength is excellent.
• Interpretation: Kaya has strong concentric/explosive output but is not yet leveraging the eccentric phase of the countermovement. She is likely "dropping into" the countermovement (CM depth was -21 cm — fairly shallow) and losing elastic energy storage. With proper coaching and plyometric work, the CMJ should overtake the SJ — and when it does, jump height could climb significantly.

What needs work — asymmetry trending the wrong direction:

• Peak Landing Force asymmetry: 14.6 → 23.3% — was inside the safe zone in Feb, now well outside it. The pattern of higher load on one side during landings is worth a coaching look.
• Peak Takeoff Force asymmetry: 10.9 → 15.9% — also moving away from the <10% target.
• SLJ height dropped 2 cm (17.0 → 15.0 cm) despite bilateral progress. Same dominant-side compensation pattern visible in other athletes — bilateral output is masking a unilateral gap.

Bottom line: Kaya is a genuinely strong young athlete with excellent concentric power. The two priorities for the next 8 weeks are: (1) develop SSC utilization so CMJ exceeds SJ — this alone could add 3–5 cm to her jump, and (2) close the unilateral / asymmetry gap before it becomes a movement habit.

2 · Session Timeline

3 · CMJ Bilateral Trends

One line per metric, one dot per session, oldest on the left. Net % is from baseline to current.

CMJ — Bilateral Jump

Counter-movement jump headline metrics across all sessions. Higher is better for jump, power, and RSI; contraction time and asymmetry are the metrics where lower is better.

4 · Bilateral Asymmetry

Bilateral Asymmetry

% asymmetry between left and right legs. The shaded green band is the <10% safe zone.

5 · Single-Leg Trends

Single-Leg Power

Best-trial single-leg jump metrics. Compares against bilateral progression to identify side-asymmetry trends.

5b · 20 May 2026 — Expanded Battery (Snapshot)

Five tests added to this session for the first time. Together they characterize Kaya's complete jump profile.

The diagnostic story this battery tells: Kaya's concentric strength (SJ, LSJ) is well-developed, but her stretch-shortening cycle is under-utilized. In healthy mechanics, CMJ should exceed SJ by 2–4 cm because the rapid countermovement stores elastic energy in tendons. Kaya's pattern (SJ > CMJ) suggests she is either pausing at the bottom of the countermovement (losing elastic energy) or descending too slowly. This is highly trainable with depth jumps, jump intent cueing, and reactive plyometrics.

6 · Programming Priorities

7 · Retest Schedule

8 · Reference Notes

All values pulled directly from the VALD ForceDecks API on 22 May 2026. Best-trial values shown unless noted. Asymmetry values reported as magnitude (worst-case across trials). RSI-Modified scaled to 0–1 range. Reference ranges drawn from age- and sex-matched normative data plus Catalyst's athlete pool. Sessions where a metric was not captured are excluded from that metric's chart.