Navicular drop test

The Navicular Drop Test (NDT), first described by Brody in 1982, is a clinical tool designed to quantify the degree of foot pronation, especially in runners [1]. The test measures the sagittal plane displacement of the navicular tuberosity from a subtalar neutral position to a relaxed standing position [2].

Test Procedure

Patient position

• Patient stands with full weight-bearing.

• Examiner positions the foot in subtalar neutral (palpating the talar head symmetrically) [3].

Measurement

1. Identify and mark the navicular tuberosity.

2. Measure the vertical distance from the navicular tuberosity to the ground.

3. Ask the patient to relax into their natural standing posture.

4. Measure again and calculate the difference in navicular height [4].

Alternative method

• Mark start and end positions on a card placed along the medial foot border, then measure displacement.

Interpretation

• Supinated foot: < 5 mm navicular drop [7]

• Neutral foot: 5–9 mm navicular drop

• Pronated foot: > 9 mm navicular drop [1][6]

• Severe arch collapse / injury risk: ≥ 10–15 mm navicular drop [5]

Evidence and Reliability

Reliability of NDT

Study	Population	Inter-rater ICC	Intra-rater ICC
Sell et al., 1994 [8]	—	0.87–0.96	0.92–0.95
Shultz et al., 2006 [9]	Healthy adults	0.56–0.67	0.91–0.97
Deng et al., 2010 [10]	Healthy adults	0.83–0.95	0.83–0.95
Langley et al., 2016 [7]	Healthy adults	—	0.40

Clinical Relevance

Increased navicular drop is associated with:

• Patellofemoral pain, patellar tendinopathy, and plantar fasciitis in runners [13].

• Medial tibial stress syndrome (MTSS) and exertional shin pain [18].

• Higher risk of ACL injuries [15][16].

• Fatigue of intrinsic foot muscles [14].

Reduced navicular drop (high arch) is associated with:

• Increased risk of ankle sprains and metatarsal stress fractures [17].

• Higher incidence of iliotibial band friction syndrome in runners [19].

Other factors:

• Foot length and sex influence results.

• Age and BMI show no significant effect [12].

Limitations and Alternatives

• NDT lacks large-scale normative data.

• Conflicting evidence exists on test reliability [10].

• Static measures do not always predict dynamic foot function.

Dynamic alternatives:

• Sit-to-Stand Navicular Drop Test (SSNDT).

• Dynamic Navicular Drop (DND).

• Deng et al. found no correlation between NDT and SSNDT, suggesting that static and dynamic assessments evaluate different aspects of foot biomechanics [10].

Conclusion

The Navicular Drop Test is a quick, simple clinical test to assess medial arch function and foot pronation. It shows moderate to high intra- and inter-rater reliability but should not be used in isolation. For accurate diagnosis, NDT is best combined with dynamic foot tests and comprehensive clinical examination.

Sources

1. Brody TM. Techniques in the evaluation and treatment of the injured runner. Orthop Clin North Am 1982;13:541-58.

2. Vinicombe A, Raspovic A, Menz HB. Reliability of navicular displacement measurement as a clinical indicator of foot posture. J Am Podiat Med Assn 2001;91:262-8.

3. Biomechanical Assessment of Foot and Ankle

4. Menz HB. Alternative techniques for the clinical assessment of foot pronation. J Am Podiat Med Assn 1998;88:119-29.

5. Shrader JA, Popovich JM Jr, Gracey GC, Danoff JV. Navicular drop measurement in people with rheumatoid arthritis: Interrater and intrarater reliability. Phys Ther 2005;85:656-64.

6. Mueller MJ, Host JV, Norton BJ. Navicular drop as a composite measure of excessive pronation. J Am Podiatr Med Assoc 1993;83:198-202.

7.  Langley B, Cramp M, Morrison SC. Clinical measures of static foot posture do not agree. Journal of foot and ankle research. 2016 Dec;9(1):45.

8. Sell KE, Verity TM, Worrell TW, Pease BJ, Wigglesworth J. Two measurement techniques for assessing subtalar joint position: a reliability study. J Orthop Sports Phys Ther 1994;19:162-8.

9. Shultz SJ, Nguyen AD, Windley TC, Kulas AS, Botic TL, Beynnon BD. Intratester and intertester reliability of clinical measures of lower extremity anatomic characteristics: Implications for multicenter studies. IClin J Sport Med 2006;16:155-61.

10. Deng J, Joseph R, Wong CK. Reliability and validity of the sit-to-stand navicular drop test: Do static measures of navicular height relate to the dynamic navicular motion during gait? Journal of Student Physical Therapy Research 2010;2:21-8.

11. Hegazy FA, Aboelnasr EA, El-Talawy HA, Abdelazim FH. Reliability of normalised truncated navicular height in assessment of static foot posture in children (6–12 years). European Journal of Physiotherapy. 2018 Apr 3;20(2):122-5.

12. Nielsen RG, Rathleff MS, Simonsen OH, Langberg H. Determination of normal values for navicular drop during walking: a new model correcting for foot length and gender. Journal of foot and ankle research. 2009 Dec;2(1):12.

13.  Spörndly-Nees S, Dåsberg B, Nielsen RO, Boesen MI, Langberg H. The navicular position test–a reliable measure of the navicular bone position during rest and loading. International journal of sports physical therapy. 2011 Sep;6(3):199.

14. Headlee DL, Leonard JL, Hart JM, Ingersoll CD, Hertel J. Fatigue of the plantar intrinsic foot muscles increases navicular drop. J Electromyogr Kines 2008;18:420-5.

15. Beckett ME, Massie DL, Bowers KD, Stoll DA. Incidence of hyperpronation in the ACL injured knee: A clinical perspective. J Athlet Train 1992;27:58-62.

16. Loudon JK, Jenkins W, Loudon KL. The relationship between static posture and ACL injury in female athletes. J Orthop Sports Phys Ther 1996;24:91-7.

17. Delacerda FG. A study of anatomical factors involved in shin splints. J Orthop Sports Phys Ther 1980;2:55-9.

18. Moen MH, Bongers T, Bakker EW, Zimmermann WO, Weir A, Tol JL, Backx FJG. Risk factors and prognostic indicators for medial tibial stress syndrome. Scand J Med Sci Sports 2012;22:34-9.

19. Glynn PE, Weisbach PC. Clinical prediction rules: A physical therapy reference manual. Boston: Jones & Bartlett, 2011.

20. Cornwall MW, McPoil TG. Relationship between static foot posture and foot mobility. J Foot Ankle Res 2011;4:1-9.

21. Kris Porter DPT. Navicular Drop and Navicular Drift. Available from: https://www.youtube.com/watch?v=nmbiabuTj2A [last accessed 30/09/2022]