Locking Stifles – A

Upward Fixation of the Patella

How to help your horse with a locking stifle

Locking stifles, in vet-speak called ‘upward fixation of the patella’ (UFP), is a rather common problem in horses, and one that is often not recognized, misdiagnosed as general hind leg lameness or overlooked altogether. While the causes are not always understood, it’s possible to help your horse overcome a locking stifle with time, patience and exercise.

This article provides a general overview of the problem and some ideas on how to recognize and treat stifle weakness or catching/locking stifles in horses.

The first step is ALWAYS to get your vet’s input. To read an excellent in-depth paper on the topic published by the AAEP with recommended exercises for PT, please click here.

horse stifle

“While the causes are not often well understood, it is possible to help horses overcome a locking stifle with time, patience, and exercise.”

horse stifle

  • What is the age, breed and gender of your horse or pony?
  • In what situations does the stifle lock and to what extent?
  • What does the pony’s body say about compensation patterns? (include images of front, back, side or video)
  • What is the pony’s history? (exercise, injury, illness)
  • How is the pony currently kept? (rough board, stall)
  • Are there any known problems? (feet, teeth, saddle fit)
  • Can he be exercised at least 3 times per week?


Are you looking for advice on how to address your horse’s or pony’s stifle issues? Are you asking yourself “does my horse have a locking stifle”? I get a number of emails every week with questions and will be happy to reply if you do not find an answer in this article.

If you are looking for advice, please email me with answers to the questions on the left. Send your request to stef at reinholdshorsewellness.com — subject “locking stifle”. I will respond to you within 1 week to let you know whether I feel I can help you via email consultation.

Please take your time, read the article and include all of the requested information in any email inquiries. This will save time and is the only way I can find time to respond. Thank you for understanding.

FIRST QUESTION: Does your horse or pony seem to be in pain? If yes –> Call your veterinarian!!! If no –> keep reading.

horse stifle problem

Incorrect riding weakens the stifle.

What does a locking stifle look like?

In severe cases, the horse will be unable to flex the respective hind leg and drag the extended leg behind him. The leg looks ‘locked’ and the horse may have to kick out or move oddly to unlock his leg. In this case, a locking stifle is hard to miss.

In milder cases, however, the problem may not be as obvious. The horse may simply appear slightly lame, have hesitant or short stepping strides, kick out during movement or hop, lose his stride, cross canter or change gaits for no apparent reason or seemingly halfway ‘collapse’ in the hind end, mostly in the canter.

NOTE: The milder cases of ‘catching stifle’ are often overlooked and sometimes interpreted as training or behavior issues.

If neglected or overlooked, secondary – especially behavioral – issues become often more predominant and make discovery of a locking stifle even more difficult.

What makes a stifle lock or catch?

First it’s important to understand the function of the locking patella in unafflicted horses. The patella corresponds to the human knee-cap. In order for a horse to stand and doze off, sleep standing up and taking weight of another leg, it’s important that the weight bearing leg ‘locks’ and becomes a sturdy pillar, such the leg of chair, to support the resting horse. It’s the patella’s job to secure the leg by locking in an upward position (for more detailed explanation of the anatomical elements involved, please see an anatomy book such as Horse Anatomy: A Pictorial Approach to Equine Structure 2 Rev Enl edition by Goody, Peter (2000) Paperback).

Things start going wrong when the the patella does not unlock when the horse wants to flex the leg. Depending on horse and severity, this can lead to panicked attempts to unlock the stifle or to a slight hop or kick.

Stifle problems often surface as ‘behavior’ issues. Rushing, not wanting to canter, panicking, rearing, etc.

Does my horse have a locking stifle? How do I know?

Get your vet involved. Only a vet can make a determination whether any of the following signs point to a locking stifle:

  • horse drags hind feet (maybe even shows wear on toe), reluctant to pick up feet
  • horse resists moving on a circle
  • horse kicks out for no apparent reason or hops (often misunderstood as behavior problems)
  • horse resists cantering or cross canters
  • horse swings hind legs to the outside while moving
  • horse tends to stumble a lot or even fall for no apparent reason

What to do to help your horse overcome a locking stifle:

Once your vet makes the determination that your horse is indeed suffering from an upward fixation of the patella, there are several things you can do to help your horse overcome this problem. I will be happy to work with you in person or via long distance consultation (video, images, skype) to develop a targeted plan for your horse. Please contact me, if you are interested in this option.

Once your vet makes the determination that your horse is indeed suffering from an upward fixation of the patella, there are several things you can do to help your horse overcome this problem. I will be happy to work with you in person or via long distance consultation.

horse with locking stifle

Captain Jack overcame his locking stifle .

“During the past year .., I have been following the guidelines you set out for Captain Jack when we first communicated. I have had marvelous success with Jack’s improved fitness and he has had neither a ‘lock’ nor a ‘click’ for over a year now.” (Nuala G.)

riding on a hill

Here some general tips to start the prevention and treatment of catching stifles:

Create trust and keep your horse supple

This is an important factor. Your horse may already be insecure and confused, you – or a former owner – may have misunderstood his antics for behavior problems and you will want to pave the way for a new way of working together.

A good way to strengthen the trusting bond between you and your horse while creating supple musculature is bodywork for horses. Engage a knowledgeable equine bodywork practitioner or learn some of the basic techniques yourself.

A good resource is the book Beyond Horse Massage: A Breakthrough Interactive Method for Alleviating Soreness, Strain, and Tension.

NOTE: Essentially, the locking stifle is your horse’s problem! Please do not try and micromanage this problem for him or make him feel like there is something ‘wrong’ with him. Instead help him manage and deal with it. This is important: Your goal is not to stop the stifle from locking, but for your horse to become relaxed, supple, and gymnasticized as well as calm enough to optimally manage his own movement and hopefully overcome the condition.
(This in a nutshell, TRUST is a BIG topic…. Contact me for distance consultation, if needed.)

Develop a gymnasticizing program and stop ‘training’ for a while

  • Until your horse is physically completely fit for his job, you are best advised to stop training. For example, while he is still dealing with a catching stifle, he doesn’t need to learn how to sidepass. You can pick this up later, once he’s completely sound. Instead, develop a gymnasticizing program for your horse. T
  • The absolute minimum is 3 x 1 hour per week of targeted gymnastic exercises. I am available for distance consultation (video, images, skype, email) and will help you develop an individualized program for your horse. Contact me to find out more.
  • You may want to use a book to help you along, such as Equine Fitness: A Program of Exercises and Routines for Your Horse or take one of my Path to Performance seminars.
  • NOTE: The trot is your friend! Skip the canter for a while.

Get out of the stall!

If at all possible, get your horse out of the stall and into an outdoor environment 24/7. This will make him move about on his own and every step taken will strengthen his quadriceps and the ligaments around the patella.

Get moving – on a hill!

Incorporate hill work into your gymnasticizing routine. Look for a GENTLE hill or an incline where you can lunge your horse on a very long line (NO small circles) in both directions in a good working trot or simply at a walk to start.

Cavaletti and Co.

Use caveletti and ground poles to get your horse to lift his legs and strengthen the quadriceps. You don’t need proper equestrian equipment. PVC pipe from the hardware store does nicely or one of the old beams that’s sitting in your barn. Anything that’s safe and has the right dimensions will do. A great resource is Ingrid Klimke’s DVD Cavaletti: The Schooling of Horse and Rider over Ground Poles.

NOTE: Start with ground poles! Do not rush into the Cavaletti until your horse is fit!

Create forward movement

Your horse will most likely move slightly on the slow and inhibited side. He may be weary of the fact that his stifle could lock at any moment. He has every right to be worried, but at the same time, he needs to move energetically, if the gymnastic exercises are to have any effect. Encourage forward movement (without rushing) and work at a good working pace. Give the horse a break when he is physically or emotionally strained. Watch for changes in breathing or worried facial expression.

NOTE: Posture is important. You will want to see the horse stretch his head forward/down. Do not proceed in an inverted posture! Create relaxation!

Go water-treading

Yes, this is easier said than done, I’m still looking for a good place to water-tread my horse in South Central Wisconsin… However, if you do have the ocean or an accessible lake or stream nearby, please feel encouraged to explore water-treading with your horse. This is an excellent exercise to strengthen all muscles without impact. Water-treading is not swimming, which is harder on the horse. Simply walk you horse through knee-high water. Most horses find it fun!

Most of all, don’t give up on your horse!

A horse with a tendency to have locking or catching stifles will need constant maintenance to remain sound and fit for riding, but chances for recovery are very good.

Alternative treatments include several forms of surgery, which you may want to discuss with your vet.

If you have a story to share or do you or a friend as yourselves “does my horse have a locking stifle”? Please email me!

Enjoy your horse!

Stefanie Reinhold