Single Leg Hop Test: Lower Limb Assessment Protocol & Norms

The single leg hop test (SLH) is a widely used functional performance test for assessing lower limb strength, power, and neuromuscular control. Originally developed as part of post-ACL reconstruction return-to-sport protocols, the single leg hop test has since been validated across a broad spectrum of clinical and athletic populations — from ACL rehabilitation to general athletic screening and age-related decline monitoring.

The test is deceptively simple: hop as far as possible on one leg and land on the same leg. Yet the distance achieved integrates quadriceps strength, hip stability, reactive strength, balance, and confidence — making it a remarkably information-dense metric. When compared bilaterally (comparing the injured to the non-injured limb, or dominant to non-dominant), it provides the limb symmetry index (LSI), which is a cornerstone criterion for return-to-sport clearance after lower limb injuries.

The single leg hop test measures the maximum horizontal distance an athlete can cover in a single hop from one foot, landing and stabilizing on the same foot. It was first described as part of a battery of functional hop tests by Noyes et al. in 1991, and has since become one of the most cited functional performance tests in sports medicine literature.

What the Test Measures

While it appears to test pure horizontal power, the single leg hop test is actually a multi-dimensional assessment. Research shows it correlates significantly with:

• Quadriceps strength as measured by isokinetic dynamometry (r = 0.65–0.82)
• Hip abductor strength and pelvic stability during landing
• Reactive strength and stretch-shortening cycle efficiency on landing
• Psychological readiness and fear of re-injury (measured by tools like the ACL-RSI scale)
• Kinematic control during single-leg loading (measured by motion capture)

Clinical Relevance

The SLH test is so embedded in return-to-sport protocols because asymmetry persists even when subjective symptoms resolve. Athletes who feel "ready" often still show meaningful limb asymmetry on hop testing, and athletes returned to sport with LSI below 90% have significantly higher re-injury rates. This makes the SLH test a uniquely objective gatekeeper for return-to-play decisions.

Equipment Needed

• Tape measure or pre-marked landing zones on the floor
• Tape for marking starting position
• Flat, non-slip surface
• Optional: video camera for kinematic screening

Warm-Up

Allow 5–10 minutes of general warm-up (light jogging, leg swings, bodyweight squats) before testing. Do not fatigue athletes with extensive warm-up — a brief targeted preparation is ideal.

Step-by-Step Protocol

1. Mark a starting line on the floor. Athlete stands on the test leg with the toe at the starting line; the non-test foot is elevated (can be held up or placed on the opposite ankle).
2. Athlete may use arm swing — encourage a natural countermovement preparation.
3. On the command "go," the athlete hops forward as far as possible on the test leg.
4. The athlete must stick the landing and hold it for 2 seconds to count as a valid trial. If the athlete touches down with the other foot, hops forward on landing, or falls, the trial is void.
5. Measure from the starting line to the heel of the landing foot.
6. Conduct 3 trials per leg with 60–90 seconds rest between trials. Record the best of 3.
7. Always test the uninjured/dominant leg first in clinical populations to establish a reference, then test the injured/non-dominant leg.

Common Errors

• Inadequate landing hold: Insist on a full 2-second stable hold — a controlled landing is as informative as the distance
• Contralateral foot touch: Any touchdown with the opposite foot voids the trial
• Toe-to-toe vs. toe-to-heel measurement: Standardize measurement to the heel of the landing foot for consistency
• Testing injured leg first: Always test uninjured leg first in clinical populations to prevent fear-based inhibition affecting the reference measurement

Calculating LSI

The Limb Symmetry Index is calculated as:

LSI (%) = (Involved Limb Score ÷ Uninvolved Limb Score) × 100

For example, if the right (involved) leg hops 145 cm and the left (uninvolved) leg hops 165 cm: LSI = (145 ÷ 165) × 100 = 87.9%.

Interpreting LSI

• ≥ 90% LSI: Commonly used as the minimum criterion for return to sport. Note that 90% LSI alone is insufficient — it should be combined with strength testing and psychological readiness.
• ≥ 95% LSI: Recommended by more conservative protocols and recent meta-analyses as the appropriate threshold.
• < 85% LSI: Indicates significant asymmetry requiring targeted rehabilitation before return-to-sport consideration.

Limitations of LSI

LSI assumes the uninvolved limb is "normal" — which is not always the case. Athletes with bilateral deficits (common in multi-sport athletes or after contralateral injuries) may show artificially favorable LSI. This is why population-based normative data is used alongside LSI. Additionally, some research shows that even athletes with >90% LSI demonstrate meaningful kinematic differences during landing tasks — suggesting that LSI alone does not fully capture neuromuscular readiness.

General Population — Males

• Below Average: < 130 cm
• Average: 130–160 cm
• Above Average: 160–180 cm
• Good: 180–200 cm
• Excellent: > 200 cm

General Population — Females

• Below Average: < 110 cm
• Average: 110–135 cm
• Above Average: 135–155 cm
• Good: 155–175 cm
• Excellent: > 175 cm

Sport-Specific Norms

• Soccer (professional males): 175–210 cm
• Basketball (college males): 175–205 cm
• Gymnastics / dance (females): 130–160 cm

Post-ACL Return-to-Sport Criteria (Multi-Criteria Model)

Current evidence recommends using the single leg hop test as one component of a multi-criteria return-to-sport decision:

1. ≥ 90% LSI on all four hop tests in the battery
2. ≥ 90% quadriceps and hamstring strength symmetry on isokinetic dynamometry
3. Psychological readiness (ACL-RSI ≥ 60)
4. Minimum time post-surgery (typically ≥ 9 months)

Athletes meeting all four criteria have substantially lower re-injury risk compared to those returned on any single criterion alone.

The SLH test is often administered as part of a four-test battery, each emphasizing slightly different qualities:

1. Single Leg Hop for Distance (SLH)

As described above — single maximum-distance hop. Emphasizes horizontal power and landing stability.

2. Triple Hop for Distance

Three consecutive hops on one leg — measures cumulative horizontal power and ability to maintain force output across repeated loading cycles. Protocol: 3 trials per leg, best of 3, measure from starting line to heel of final landing.

3. Crossover Hop for Distance

Three consecutive hops alternating across a 15 cm line — adds a mediolateral challenge, targeting hip abductor control and frontal-plane stability. More sensitive to ACL-specific deficits than the standard SLH.

4. 6-Meter Timed Hop

Timed single-leg hops over 6 meters — tests reactive strength and rate of force development over repeated shorter hops. Faster is better; typical performance for recreational athletes is 2.0–2.6 seconds per leg.

Battery vs. Single Test

Using all four tests improves sensitivity and specificity for detecting limb asymmetry compared to any single test alone. If time allows only one test, the triple hop for distance is often recommended as it has the highest reliability (ICC 0.92–0.97) and correlation with functional performance.

Improving Single Leg Hop Distance

Performance on the SLH test improves in response to both strength and plyometric training. The key targets:

• Quadriceps strength: Leg press (single-leg), Bulgarian split squat, step-up with progressive loading. Target ≥ 2x bodyweight leg press on involved side.
• Glute and hip strength: Single-leg hip thrust (3x10), Copenhagen adduction exercise (3x8), lateral band walks
• Reactive strength: Single-leg box drops (step off 15–20cm box, stick landing), single-leg bounds, single-leg pogo hops
• Landing mechanics: Video-feedback training for knee alignment during landing; focus on controlled, soft landing with hip and knee flexion (not stiff-knee/valgus collapse)

Progressive Plyometric Protocol

1. Phase 1: Two-leg to one-leg landings (jump off two feet, land on one) — develops landing mechanics under lower load
2. Phase 2: Single-leg box drops — static start, land and hold 2 seconds
3. Phase 3: Single-leg hops for distance — submaximal effort with emphasis on landing quality
4. Phase 4: Maximum effort single-leg hops — testing conditions, full effort

Using PoinT GO for Monitoring Progress

PoinT GO's jump tracking features allow you to monitor single-leg reactive strength index (RSI) over time — providing a more sensitive metric of neuromuscular development than distance alone. Tracking RSI trends helps identify when an athlete is ready to progress through the plyometric phases above.