Suitable for submersion (up to 1 metre)
Activity Level 2

AvalonK2 is a hydraulic ankle that has been designed specifically for the complex needs of limited community ambulators. Through a combination of award-winning hydraulic ankle technology and a unique optimised keel, Blatchford has created a prosthesis that works with the user to enhance confidence, independence and safety.

Enhancing walking confidence by hydraulically adjusting to inclines and self-aligning to secure the knee joint, AvalonK2 encourages good posture and joint position. This improves stability, helping to prevent falls and increases balanced limb loading to provide the best performance for limited community ambulators.

Key Features

  • Hydraulic ankle technology designed to replicate natural motion
  • Optimised keel shape enhances walking stability
  • Plantarflexion compliance when descending slopes
  • Increased range of motion to enable greater sit-stand transfer safety
  • Increased shock absorption, reduction in interface pressures
  • Remains dorsiflexed for increased toe clearance in swing phase
  • Waterproof
  • Sandal toe foot shell

Foot shell and glide sock included.

AvalonK2 Unique Design

The main driving force behind advancing lower limb prosthetic technology in the 21st century is biomimetic design; reproducing the biomechanical performance of natural limbs. Inherent in this is recognising that different demographics of the amputee population have different biomechanical requirements, and that the engineering principles behind different devices must accommodate for this. With over 128 years of innovation and expertise in lower limb prosthetic technology our award-winning prosthetic products are designed with the patient in mind.

Hydraulic Ankle Technology

Hydraulic ankles help align the body interface with the ground interface, allowing for more natural movement and posture. By continuously adjusting to absorb energy, our hydraulic ankles allow for an efficient roll-over, remaining in a dorsiflexed position, increasing clearance to help reduce the risk of falls. This technology has been proven to provide a number of benefits to limited community ambulators optimising posture and comfort.

AvalonK2 Range of MotionRange of Motion

An important design consideration of AvalonK2 was to enable the user to stand from a seated position in a safe and comfortable way. In addition to the keel and shape, the 6° of dorsiflexion allows the base of support to be moved closer to the body’s centre-of mass making it easier to sit-stand.

Purpose Designed Keel

Limited community ambulators tend to walk more slowly, with a shorter step and stride length. Providing a foot keel that is designed to accommodate natural changes in gait can provide a smoother rollover for such users. The optimised keel shape of AvalonK2 considers such requirements and encourages a consistent, stable, and comfortable rollover so the user can walk more easily and move around confidently

Scientifically Proven


Clinical Compendium

Clinical Compendium

Blatchford Biomimetic Hydraulic Technology mimics the dynamic and adaptive qualities of muscle actuation to encourage more natural gait. Multiple independent scientific studies, comparing Blatchford hydraulic ankle-feet to non-hydraulic feet, have shown:

  • Greater comfort, reduced socket pressures
  • Improved safety, reduced risk of trips and falls
  • Smoother, easier and more natural gait
  • More evenly balanced inter-limb loading
  • Greater satisfaction

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Clinical Evidence

Download the AvalonK2 Whitepaper

White Paper: A Study of AvalonK2

To take a more in-depth look into AvalonK2, discover our White Paper ‘A Study of AvalonK2’ where the biomechanics of the limited community ambulators gait are considered along with the latest clinical evidence for biomimetic hydraulic technology. Then uncover how the biomechanical performance of AvalonK2 can improve mobility and independence.

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Download the AvalonK2 Whitepaper

White Paper: A Study of Hydraulic Ankles

Over a decade after challenging conventional wisdom, new scientific evidence continues to be published on the medical advantages of hydraulic ankles. Discover our White Paper ‘A Study of Hydraulic Ankles’. 

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AvalonK2 Clinical Evidence Reference

Improvements in Clinical Outcomes using Avalon compared to non-hydraulic feet

  • Improved gait performance
    • Faster self-selected walking speed1
    • Smoother centre-of-pressure progression1
  • Keel and ankle designed for Activities of Daily Living
    • Easier sit-to-stand2
  • Mean 34% reduction in stance phase timing asymmetry3
  • Maximum 86% reduction in stance phase timing asymmetry3
  • More symmetrical inter-limb loading1
  • Patient reported outcome measures indicate improvements
    • Mean improvement across all Prosthesis Evaluation Questionnaire domains4

Clinical Outcomes using the Avalon/Navigator keel design

  • Shorter keel allows for more consistent rollover radius of curvature, regardless of changing footwear5
  • The most energy efficient radius of curvature for a rollover shape has been identified as 30% of the walker’s leg length. For a person of a typical adult height between 1.5m and 1.8m, this equates to approximately 245-290mm. The Avalon keel design has a rollover shape of ~250mm5.


1. Barnett CT, Brown OH, Bisele M, et al. Individuals with Unilateral Transtibial Amputation and Lower Activity Levels Walk More Quickly when Using a Hydraulically Articulating Versus Rigidly Attached Prosthetic Ankle-Foot Device. JPO J Prosthet Orthot 2018; 30: 158–64.
2. McGrath M, Moser D, Baier A. Anforderungen an eine geeignete Prosthesentechnologie für ältere, dysvaskuläre Amputierte - Requirements of a suitable prosthesis technology for elderly, dysvascular amputees. Orthop-Tech; 11. Download
3. Moore R. Effect on Stance Phase Timing Asymmetry in Individuals with Amputation Using Hydraulic Ankle Units. JPO J Prosthet Orthot 2016; 28: 44–48. Download
4. Moore R. Patient Evaluation of a Novel Prosthetic Foot with Hydraulic Ankle Aimed at Persons with Amputation with Lower Activity Levels. JPO J Prosthet Orthot 2017; 29: 44–47. Download
5. Curtze C, Hof AL, van Keeken HG, et al. Comparative roll-over analysis of prosthetic feet. J Biomech 2009; 42: 1746–1753.

See all the Clinical Evidence for every Blatchford product in our Clinical Evidence Finder Tool.

AvalonK2 Technical Data

Max. User Weight:


Activity Level:


Size Range:


Component Weight:


Build Height:


Heel Height:


†Component weight shown is for a size 26cm without foot shell.


Alignment Wedge 940093


AV 25 L
  Size Side

For dark tone add suffix D. 
Foot example: AvalonK2 size 25 left.