Jack Test

Original Editor - Lauren Heydenrych

Top Contributors - Lauren Heydenrych

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The purpose of the Jack test/ Jack's test (or Hubscher maneuver) is to assess the functionality of the windlass mechanism and stability of the arch of the foot.[1] In this regard it is often used to determine if the presentation of pes planus in an individual is a fixed (rigid) or flexible deformity.[2]It is important to differentiate flexible from fixed as the prognosis and intervention of the two presentations are vastly different. In addition, the presentation of a fixed flatfoot deformity flags possible underlying pathologies which could include cerebral palsy, other tone-influencing pathologies or tarsal coalition[3].

Jack's test was first described in 1953. While not being used as a diagnostic tool all on its own, this simple clinical test can be helpful when considered in context.[4]

Jack's test is often done in conjunction with the Tip Toe Standing test.

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Jack's test is performed in a weight bearing/ standing.[5]

  1. The patient is to stand in a normal, relaxed position,
  2. The clinician then passively flexes the 1st metatarsal joint (big toe).

Result and Interpretation
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In a flexible pes planus, the following is observed:[5]

  • The arch of the foot rises
  • The posterior part of the foot assumes an inverted position.
  • The leg rotates laterally.
  • A tight band is noted in the region of the plantar aponeurosis.
  • In addition to elevation of the MLA (medial longitudinal arch), talonavicular joint congruity can also be observed.

The manual dorsiflexion of the hallux of the first metatarsophalangeal joint tightens the plantar fascia and in turn shortens the distance between metatarsal heads and heel. This ultimately elevates the MLA.[4]

If no arch appears or hallux dorsiflexion is difficult the patient may present with a foot type including: ankle equinus, vertical/oblique talus, tarsal coalition, peroneal spasms, hypotonia, general ligament laxity or apropulsive gait.[4] Apropulsive gait where a patient fails to demonstrate a heel-to-toe gait during the propulsive phase of gait. This is mainly seen in children with delayed milestone development.[6][4]

Resources[edit | edit source]

References[edit | edit source]

  1. Richie Jr DH. Biomechanics and clinical analysis of the adult acquired flatfoot. Clinics in podiatric medicine and surgery. 2007 Oct 1;24(4):617-44.
  2. Lee MS, Vanore JV, Thomas JL, Catanzariti AR, Kogler G, Kravitz SR, Miller SJ, Gassen SC. Diagnosis and treatment of adult flatfoot. The Journal of Foot and Ankle Surgery. 2005 Mar 1;44(2):78-113.
  3. Halabchi F, Mazaheri R, Mirshahi M, Abbasian L. Pediatric flexible flatfoot; clinical aspects and algorithmic approach. Iranian journal of pediatrics. 2013 Jun;23(3):247.
  4. 4.0 4.1 4.2 4.3 Evans E. Jack's Test [Internet]. 2017 [cited 18 August 2022] Available from: https://angelaevanspodiatrists.com.au/evidence-essentials-blog-5-april-2017/
  5. 5.0 5.1 Hicks JH. The mechanics of the foot: II. The plantar aponeurosis and the arch. Journal of anatomy. 1954 Jan;88(Pt 1):25.
  6. Wrobel JS, Crews RT, Connolly JE. Clinical factors associated with a conservative gait pattern in older male veterans with diabetes. Journal of foot and ankle research. 2009 Dec;2(1):1-5.
  7. DOLA Orthotics. DOLA Orthotics - Clinical Tests:: Jacks Test. Available from: https://www.youtube.com/watch?v=4jTKFC8dmtE [last accessed 23/08/2022]
  8. Vince Mosca. Assessing Foot Flexibility: Part 04 (Toe Raise "Jack" Test). Available from: https://www.youtube.com/watch?v=R1AGYMt329k [last accessed 18/08/2022]