No red flags. Item to monitor — lower-limb asymmetry: a 13% left/right difference in the jump, above the 10–15% reference — one leg is doing measurably more of the work. Addressable within normal programming; re-test to confirm it resolves.
Where Krish stands — and where we take him next
Watching · Lower-Limb Asymmetry — a 13% left/right difference in the jump, above the 10–15% reference — one leg is doing measurably more of the work.Where to go: single-leg strength & unilateral loading on the weaker leg, then re-test.
Developing · Vertical Jump — 14.9", at the Age-Group reference; the priority quality to build.Where to go: HS Varsity (20") — via explosive strength.
Holding well — leg power ≥HS-varsity, reactive strength ≥HS-varsity, throwing-shoulder ER, landing control within/above reference.Where to go: maintain through the block; monitor for fatigue-driven drops.
Athlete Map — Flags by Region
ShoulderBalanced
Throwing-arm external rotation is 7% above the non-throwing arm — normal thrower adaptation, not a concern. ER:IR is the number to watch here.
LegsAsymmetry
Interlimb jump asymmetry 13% — exceeds the 15% flag threshold. Single-leg strengthening priority.
How to read it: each spoke is one quality, scored from developing (center) to elite (outer edge). The bigger and more even the shape, the better — a spoke pulled toward the center is a focus area. Toward the edge = stronger
Read for his position · Pitcher
On the mound, velocity is built from the ground up — leg drive and hip rotation generate the pitch, and the arm only finishes it. So we weight lower-half power (velocity), landing / deceleration and lower-limb symmetry (the braking that protects a high-volume throwing arm), and the throwing-shoulder ER:IR (the arm's own brakes) most heavily. Every number below is read through that lens.
Throw Harder — The Velocity Engine
What we measured: how much power, explosiveness and spring the legs and body produce on a force plate. Why it matters: up to half of throwing velocity comes from the lower half — stronger legs mean more velocity and less strain on the arm.
Why we test the legs: the lower half is the fastest, safest place to add on-field performance — power here becomes velocity and bat speed without ever loading the arm. The three tests below are performance markers; each one has a target for his age, and we care most about the trend line over the season. The injury screens follow in the next section.
Leg Power — mound velocity & bat speedPerformance
Peak force the legs drive into the ground.
53.5W/kg Strong
Assessment: Above the HS-varsity reference. Force production is a strength. Directive: maintain strength, shift emphasis to rate-of-force-development (speed-strength).
Reference range: 52+ W/kg is a strong mid-teen, 60+ is elite; under 45 is still developing. The exact number matters less than the slope — we want it climbing every screen as he gets stronger.
Performance role: This is the engine room. Up to half of pitch velocity and much of bat speed come from the legs driving into the ground — so it's a performance marker first, and because strong legs spare the arm, an injury lever too.
Explosive Jump — total-body popPerformance
How high he moves his whole body — raw explosiveness.
14.9" Solid
Assessment: At the age-group reference, below HS-varsity (20″). Directive: progress explosive/ballistic strength (jump squats, med-ball throws).
Reference range: 12–15″ is solid at this age, 15–18″ strong, 18″+ elite. It rises fast through the growth years, so we track the trend more than any single reading.
Performance role: Vertical pop is total-body explosiveness — the same fast force behind a first step, a crossover, and jumping on a fastball. A pure athleticism marker.
Reactive Spring — quick first step & stridePerformance + durability
How fast he stores & returns energy off the ground.
2.19 Strong
Assessment: RSI above the HS-varsity reference. Strong reactive capacity. Directive: maintain, progress amplitude/intensity.
Reference range: An RSI of 2.0+ is strong; under 1.5 is still developing. It reflects how stiff and efficient his tendons are — something that responds well to simple plyometric work.
Performance role: Spring is quick re-use of force — first-step burst, stealing bases, exploding out of the box. It also flags tendon durability, so it reads as both performance and resilience.
Durability Screens — Symmetry, Cuff & Load
Durability Screen · Arm Health
Throwing Shoulder — Rotator-Cuff
What we measured: external- and (where captured) internal-rotation strength of the throwing shoulder via handheld dynamometry, with the non-throwing arm as a baseline. Why it matters: a low throwing-arm ER:IR ratio, or a throwing-arm ER deficit versus baseline, means the decelerators are underpowered relative to the throwing muscles — a strength imbalance worth correcting for arm durability, and one we track over time.
How to read the shoulder: on the throwing arm, the external rotators (posterior cuff) decelerate the arm after release. The most-studied shoulder number is the throwing-arm ER:IR ratio — decelerators (ER) vs accelerators (IR); a low ratio has been associated with elbow injury in throwers, though thresholds aren't firmly settled. The non-throwing arm is only a baseline. A throwing arm that's stronger is normal, expected adaptation, not a concern (the glove-side arm doesn't brake the throw — its job is trunk blocking to get on top of the ball). Bilateral strength difference on its own is a weak injury signal, so we treat a throwing-arm deficit as a strength target worth correcting and track it over time — not a prediction.
★ Throwing-Arm ER : IR Ratio — the key number
Not yet computed — internal rotation wasn't captured this session. Add an IR test next visit to complete the ratio, which is the primary throwing-shoulder metric.
Assessment: Throwing-arm external rotation is 7% above the non-throwing arm — expected thrower adaptation, not a deficit. (ER:IR pending — capture IR next visit.) No shoulder corrective indicated.
Reference range: throwing-arm ER:IR ≥0.70; throwing-arm ER at or above the non-throwing baseline (a >10–15% deficit flags).
Durability Screen · Asymmetry
Lower-Limb Symmetry
What we measured: left-vs-right balance across the three phases of the countermovement jump — take-off, loading, and landing. Why it matters: each phase loads the body differently, so we assess all three. A large asymmetry is first a performance leak (one side doing more work = less total output) and a plausible durability concern; as a standalone injury predictor the evidence is mixed, so we treat it as a training target and watch the trend.
Working thresholds: under 10% = balanced; 10–15% = monitor with unilateral work; over 15% = prioritise single-leg training. These bands are a common convention, not a hard rule — the more useful signal is how an athlete's own symmetry changes over time. We report all three phases every session, in range or not.
Propulsion (Take-Off) Durability
2%Balanced
The phase: The push-off / drive phase — how much force each leg produces to accelerate the body upward. In baseball this is the back-leg drive down the mound and the push through a rotational swing.
Why asymmetry in this phase raises injury risk: When one leg out-produces the other, the stronger side is chronically overloaded while the weaker side stays under-built — driving overuse on the dominant leg and compensations up the kinetic chain that alter throwing and hitting mechanics. Even push-off is also a standard clearance criterion after any lower-body injury.
Assessment: 2% difference — within the <10% reference. This phase is symmetrical; no corrective action indicated. Shown to confirm it was reviewed.
Braking (Loading) Durability
16%Flag
The phase: The loading / deceleration phase — each leg lengthens under load to absorb and store energy (coiling the spring) before reversing to drive up. In baseball it's the same eccentric load a pitcher's front leg takes as it blocks and the hips fire, and the load a hitter's back leg absorbs before it rotates into the ball.
Why asymmetry in this phase raises injury risk: This is the phase of highest tissue load — the muscle produces force while lengthening (eccentric), which is where many soft-tissue strains occur. A sizeable imbalance means one leg carries more of that eccentric load; evening it out is sensible for durability and total output, even though asymmetry on its own isn't a reliable injury predictor.
Assessment: 16% difference, left leg lower — exceeds the 15% flag threshold. Prescribe targeted single-leg strengthening on the left side; re-test to confirm it closes.
Landing (Absorption) Durability
13%Monitor
The phase: The impact-absorption phase — how each leg accepts ground-reaction force on the way down. It mirrors the deceleration a pitcher's body absorbs after ball release and the landing off a stolen-base slide or a jump.
Why asymmetry in this phase raises injury risk: Landing symmetry is a standard return-to-sport screen after knee injury — the favoured leg is spared while the loaded leg absorbs more impact. Of the three phases it has the clearest injury link, though prediction in healthy athletes is still debated. We flag large gaps, correct them, and re-check over time.
Assessment: 13% difference, left leg lower (10–15% monitor band). Add unilateral / single-leg loading and re-test to prevent it widening.
Durability Screen
Landing & Deceleration
What we measured: how much force his body absorbs when he lands off a jump. Why it matters: every throw ends in a violent deceleration — if the legs can't brake it, that load travels up into the elbow and shoulder.
Why we test landing: the body decelerates a throw with much the same system it uses to absorb a landing, so how well he brakes a landing is a window into how well his legs offload the arm. We read it as a durability marker and, like the rest, track how it changes over time.
Landing Load — the arm protectorDurability
Peak force absorbed on impact, in body weights.
7.3× BW Moderate
Assessment: Moderate landing load (7–8× BW). Directive: monitor; include eccentric and landing-mechanics drills in warm-ups.
Reference range: Under ~7× body weight is well-controlled; 8× is stiff, 9×+ is high. Here lower is better — it means muscle, not joint, is absorbing the force.
Performance role: The body decelerates a throw much like it absorbs a landing, so better lower-body braking keeps load off the joints and, by extension, the arm. A durability marker more than a performance one — and one we track for change over time.
Performance Benchmarks — Rank vs. Level
Performance measures (distinct from the injury screens above). These are the qualities that translate to on-field tools — mound velocity, bat speed, first-step quickness, base-running burst — so we plot each against the level he's chasing, not just his own prior results.
How to read it: the teal marker is the current value; the ticks are typical Age-Group (13–15), High-School Varsity, College and Elite/Pro reference levels (internal ranges informed by published normative data).
Vertical Jump14.9"
▸ 5.1" from HS Varsity level — his next rung.
Leg Power53.5 W/kg
▸ 6.5 W/kg from College level — his next rung.
Reactive Spring2.19
▸ 0.31 from College level — his next rung.
Priority performance quality — Vertical Jump
Ranks lowest of the three performance measures relative to its benchmark; largest gap to the HS Varsity reference (20"). Primary development target: explosive strength — trap-bar jumps, med-ball throws and heavy-but-fast lifts build the vertical that shows up as bat speed and first-step quickness.
Training Directives — Krish Nair
Prioritised actions for the current training block, drawn directly from the data above — spanning injury correction, performance development, and monitoring.
Protect
Injury targets (1) — correct the 13% interlimb jump asymmetry with single-leg strength and unilateral loading.
Build
Priority quality — vertical jump, 14.9" (toward the HS Varsity reference (20")): explosive strength — trap-bar jumps, med-ball throws and heavy-but-fast lifts build the vertical that shows up as bat speed and first-step quickness.
Sustain
Re-test schedule — frequent, brief re-screens — the model used with professional athletes. Reactive strength and propulsive output are sensitive markers of neuromuscular fatigue; tracking them flags accumulated load before performance or tissue tolerance is compromised, and quantifies training response over time. Add hip/shoulder mobility screening to complete the profile.
Why We Keep Screening
This is Screen #1 — the baseline. What matters most is the direction each number moves over time.
Development: these qualities change fast in young athletes — frequent testing turns training into a measured, improving line instead of guesswork.
Fatigue & load: reactive strength and power dip when an athlete is run down — often before he feels it or gets hurt. Catching that early lets us adjust before it becomes a slump or a strain.
The next level: every screen is a chance to move up the benchmark ladder toward high-school and college standards — the same way pro athletes are monitored year-round.
Supporting Detail — The Finer Numbers
Squat-Jump Power
55.9W/kg
Leg drive with no dip — pure push power.
Ground Contact
0.16s
Time on the ground per hop — shorter is springier.
Peak Power
2,809W
His single most explosive instant.
Jump Efficiency (mRSI)
0.53
Height gained per unit of effort.
What this screen is — and isn't
An objective, repeatable profile of strength, power, symmetry and control. Its most reliable use is tracking an athlete's own numbers over time — development, fatigue/readiness, and return from injury. Strength and symmetry findings here are training targets worth correcting, not a prediction that an injury will happen; the research on asymmetry and injury is genuinely mixed. The largest, best-established levers in youth arm health are workload-related — sensible pitch counts, not throwing while fatigued, and rest from year-round play. This screen complements that; it doesn't replace it.
Methodology. VALD dual force plates (jump power, reactive strength, landing load) + VALD DynaMo handheld dynamometry (shoulder rotator-cuff strength) — the same tools used across MLB, college and Olympic programs. Benchmark bands are internal reference ranges for 13–15-year-old athletes, informed by published normative data; the throwing-arm ER:IR reference (≥0.70) reflects shoulder-injury research in throwers, where thresholds remain an active area of study. Asymmetry thresholds (10–15%) are common working conventions, not validated cut-points. This is a wellness & performance screen, not a medical diagnosis or an injury-prediction tool.
Holistic Baseball × Catalyst Performance · The Studio by Catalyst, Rancho Bernardo.