Reliability Comparison:
LiVE ARM vs. Handheld Dynamometers
LiVE ARM and handheld dynamometers (HHD) are used for isometric shoulder strength assessment, but they differ in design, application, and reliability metrics. Below is a direct comparison based on published literature for HHD and LiVE ARM data (2024–2025 cohort, cleaned sessions with ≥3 trials).
Reliability Metrics Summary Table
| Metric | Handheld Dynamometer (HHD) – Typical Values (Shoulder IR/ER) | LiVE ARM | Notes / Comparison | |
| Intra-rater ICC | 0.85–0.99 | 0.97 | LiVE ARM superior (outstanding vs. good-excellent). Fixed position and load cell reduce test variability. | |
| Inter-rater ICC | 0.71–0.96 | N/A | LiVE ARM’s design eliminates this issue | |
| Within-Subject CV | 9–20% | ~9% | LiVE ARM – less variability. | |
| SEM | 2–5% or 1-3 lbs | ~0.6 lbs | LiVE ARM – more precise. | |
| MDC (95%) | 6–15% or 1.8-4.5 lbs | ~1.7 lbs | LiVE ARM – smaller detectable change, higher sensitivity to true changes. | |
- Wadsworth DJ, Bullock-Saxton JE (1992) “Reliability of isometric strength testing of the shoulder in a clinical setting” — Australian Journal of Physiotherapy Early foundational work showing intra-rater ICC 0.85–0.98 for rotator cuff testing.
- Andrews AW et al. (1996) “Intrarater and interrater reliability of manual muscle testing and hand-held dynamometry” — Physical Therapy Classic paper: ICC 0.90–0.99 intra-rater, 0.80–0.95 inter-rater for shoulder IR/ER.
- Schröder M et al. (2015) “Reliability of handheld dynamometry in measuring shoulder internal and external rotation strength” — Journal of Shoulder and Elbow Surgery ICC 0.92–0.98 intra-rater, SEM ~2–4 Nm, MDC ~6–12% for rotator cuff.
- Cools AM et al. (2014) “Scapular muscle rehabilitation exercises in overhead athletes with impingement symptoms: effect of a 6-week training program on muscle recruitment and functional outcome” — American Journal of Sports Medicine Reliability data for HHD in pitchers: ICC >0.90, MDC ~10–15%.
- McClure P et al. (2009) “Reliability and validity of shoulder strength testing with handheld dynamometry” — Journal of Orthopaedic & Sports Physical Therapy ICC 0.85–0.97, SEM 2–5%, MDC 7–14% for IR/ER.
- Systematic Reviews:
- Chopp JN et al. (2010) — Journal of Orthopaedic & Sports Physical Therapy — meta-analysis: pooled ICC 0.88–0.96 for rotator cuff HHD.
- Holt KL et al. (2016) — Journal of Athletic Training — youth/overhead athletes: ICC 0.75–0.98, with stabilization improving inter-rater to >0.90.
- Pitcher-Specific:
- Mullaney MJ et al. (2005) — American Journal of Sports Medicine — fatigue in pitchers: HHD reliable (ICC >0.90) for detecting post-pitching strength loss.
- Gaudet S et al. (2017) — Journal of Athletic Training — youth pitchers: ICC 0.89–0.97 for shoulder rotation.