Navicular Drop Test

Original Editor - Evan Thomas

Top Contributors - Evan Thomas, Manisha Shrestha, Kim Jackson, Kai A. Sigel and Tony Lowe

Purpose

The Navicular Drop Test (NDT) was first described by Brody in 1982 as a means of quantifying the amount of foot pronation in runners.[1] It is the one of the static foot assessment tool and is intended to represent the sagittal plane displacement of the navicular tuberosity from a neutral position i.e. Subtalar joint neutral to a relaxed position in standing (Fig. 1).[2]

Technique

Position the patient in standing so there is full weight-bearing through the lower extremity and ensure the foot is in the subtalar joint neutral position (“talar head congruent”)[3]. Mark the most prominent part of the navicular tuberosity and measure its distance from the supporting surface (floor or step). Ask the patient to relax and then measure the amount of sagittal plane excursion of the navicular with a ruler (Fig. 1).[4] Alternatively, the test can also be performed in reverse, i.e. measuring from relaxed position up to talar neutral in standing postion. Many clinicians also choose to perform this test by marking the start and end position of the navicular on an index card placed along the inside of the foot and then measure the change with a ruler.


Navicular Drop Test


Figure 1. Measurement of navicular drop. The height of the navicular tuberosity is measured in neutral (A) and relaxed (B) stance positions, and the amount of excursion is measured. Image from Menz 1998.[4]

Navicular Drop Test video provided by Clinically Relevant

Evidence

Table 1. NDT Values

Supinated foot Neutral foot Pronated foot
6-8mm[5] ≥10-15mm[1][6]
<5mm[7] 5-9mm >9mm


Table 2. Measurement of navicular height in standing

Study Population Inter-rater reliability (ICC) Intra-rater reliability (ICC)
Sell et al 1994[8] --- 0.87-0.96 0.92-0.95
Shultz et al 2006[9] Healthy 0.56-0.67 0.91-0.97
Deng et al 2010[10] Healthy 0.83-0.95 0.83-0.95
Ben Langley et al 2016[7] Healthy 0.40


Table 3. Performance of the NDT

Study Population Inter-rater reliability (ICC) Intra-rater reliability (ICC) Sensitivity Specificity
Mueller et al 1993[6] Healthy 0.78-0.83 ---
Sell et al 1994[8] --- 0.73 0.83
Shrader et al 2005[5] Rheumatoid Arthritis 0.85-0.97 0.90-0.98
Aboelnasr EA et al 2019[11] 6-12 years School going children 0.98 88.1% 99.5%

 Foot length had a significant influence on the navicular drop in both men (p < 0.001) and women (p = 0.015), whereas no significant effect was found of age (p = 0.27) or BMI (p = 0.88). Per 10 mm increase in foot length, the navicular drop increased by 0.40 mm for males and 0.31 mm for females[12]

Clinical Relevance

The function and structure of the medial longitudinal arch (MLA) of the foot has been proposed as a risk factor for developing injuries which is determined by the navicular position.

Increased navicular drop (ND) leads to the low MLA which has been determined to be a risk factors

  • for sustaining injuries among novice runners exhibiting more knee pain, patellar tendinitis and plantar fasciitis[13] 
  • developing exercise related lower leg pain and patellofemoral pain syndrome.[13]
  • Headlee et al also found a positive NDT as being indicative of plantar intrinsic muscle fatigue.[14]
  • Excessive navicular drop has been reported in patients with a history of ACL tears[15][16] and is thought to predispose individuals to shin splints[17] and medial tibial stress syndrome.[18]

Decreased navicular drop leading high arched reported a greater incidence of ankle injuries, stress fractures of the fifth metatarsal and iliotibialband friction syndrome in runners.

It may also help identify individuals who would benefit from prefabricated orthotics and modified activity in those with patellofemoral pain syndrome.[19] NDT may also be of benefit assessing patients with overuse symptoms of the lower extremity.[2]

It should also be noted that despite its relatively widespread use being simple and quick clinical measure, it lacks normative data from a large cohort of healthy individuals[20][10] and conflicting opinion on the reliability of the measure.[10] As with any clinical test, the results should interpreted with caution and informed clinical decisions should be made in light of the error associated with each technique.[2] The NDT is only one component of an overall lower extremity evaluation and should be used in conjunction with other techniques.[8]

The intricacies with navicular tuberosity and sub-talar joint palpation and percent weight bearing through the lower extremity are some factors for inconsistent reliabilty. So to addresses some of these issues other versions of the test exist, such as one involving a single leg stance relaxed position, the sit-to-stand navicular drop test (SSNDT) and Dynamic navicular drop ( DND).[10]

Deng et al found no correlation between NDT and the sit-to-stand version (SSNDT), suggesting the static measures of navicular height change may not predict dynamic navicular motion during the gait cycle.[10]

Resources

References

  1. 1.0 1.1 Brody TM. Techniques in the evaluation and treatment of the injured runner. Orthop Clin North Am 1982;13:541-58.
  2. 2.0 2.1 2.2 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. 4.0 4.1 Menz HB. Alternative techniques for the clinical assessment of foot pronation. J Am Podiat Med Assn 1998;88:119-29.
  5. 5.0 5.1 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. 6.0 6.1 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. 7.0 7.1 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. 8.0 8.1 8.2 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. 10.0 10.1 10.2 10.3 10.4 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. 13.0 13.1 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.