FlexAbility - Limb motion, lameness, ease of movement, muscle tone
QUESTION: Does feeding an oral joint supplement improve equine limb motion, and orthopedic, physiotherapy and handler evaluation scores?
This study has been published: Murray et al. (2017) A Randomised, Blinded, Crossover Clinical Trial to Determine the Effect of an Oral Joint Supplement on Equine Limb Kinematics, Orthopaedic, Physiotherapy, and Handler Evaluation Scores. Journal of Equine Veterinary Science 50 121–128.
Note: This study was conducted on the original formulation of FlexAbility. FlexAbility PLUS also contains hyaluronic acid.
- Blinded, placebo-controlled crossover study to determine effect of joint supplement.
- Horse limb kinematics, clinical orthopedic, physiotherapy, and handler evaluation.
- Supplement S (FlexAbility, Science Supplements) or placebo was fed to 24 horses for 21 days each.
- S associated with improved kinematics, orthopedic, physiotherapy, and handler grade.
- Potential benefit to use of supplement S in clinical patients during rehabilitation.
Despite the range of oral joint supplements available, there has been very limited research into their efficacy. The study aimed to determine the effect of an oral joint supplement on limb kinematics, orthopedic, physiotherapy, and handler evaluation in horses. Supplement S or placebo P was fed to 24 horses for 21 days each in a random order. Horses were evaluated at days 0 (baseline), 21 (after first treatment), and 42 (after second treatment). Assessments included the following: clinical orthopedic evaluation for straight line/lunging circle in walk and trot; high-speed motion capture determined hind limb kinematics for straight-line trotting; grading of limb range of motion (ROM) and muscle tone based on standardized physiotherapy criteria; handler grading of specific criteria during pasture, groundwork, and ridden exercise. Effect of treatment, sequence, limb, and interactions were investigated using linear-mixed models. S was associated with significantly lower lameness grade in a straight line (P = .001) and circle (P = .010), with individual horses improving up to 2/10 grades over P/baseline. S was associated with significantly improved ROM and muscle tone. Ridden/groundwork scores were significantly higher with S compared to P/baseline. With S, horses were graded significantly higher for “ease of movement” at pasture compared with P/baseline. For horses with hind limb lameness, S was associated with significantly greater tarsal flexion than baseline (4.2% greater, P < .020) or P (2.7% greater, P < .037). S was associated with less lameness and improved physiotherapy scores, ridden/groundwork scores, and pasture “ease of movement.” Increased mid-stance tarsal flexion of lame limbs may indicate improved mobility/comfort during peak loading, supporting a positive effect of S.
Keywords: Horse, Lameness, Nutraceutical, Physiotherapy, Oral joint supplement
- Despite the broad range of equine oral joint supplements available, there has been very limited research into their efficacy.
Aim of Study
To determine the effect of an oral joint supplement on limb motion, and orthopedic, physiotherapy and handler evaluation in horses.
- Placebo-controlled = some horses received the joint supplement and some received a supplement with no active ingredients (placebo). Use of a placebo helps reduce bias (seeing a false positive result) and allows for the fact that an improvement might be observed from horses spontaneously improving.
- Randomized = which horses were given placebo first was pre-determined by a random system rather than a person deciding at the time of seeing a horse. This removes bias in the results caused by selecting only certain horses (e.g. less lame horses) to have a particular treatment.
- Blinded = none of the people assessing the horses knew which horses received the joint supplement and which received the placebo supplement. Blinding removes bias caused by people wanting to see a positive effect with the joint supplement e.g. by giving it to the least lame horses or grading these horses less harshly.
- Crossover = all horses received both the joint supplement and the placebo which allows the response of a horse to the real supplement to be compared with the same horse's response to the placebo supplement. Removing horse to horse variation in this way makes crossover trials potentially more efficient than similar sized, parallel group trials in which each horse is exposed to only one treatment.
Seventeen mares and seven geldings completed the study, with an average age of 8 years. No horse had received any medication for at least 7 days prior to the study or was on any ongoing treatment that could have had an effect on performance/locomotion, as per International Equestrian Federation guidelines. The joint supplement (FlexAbility, Science Supplements) or placebo was given to horses in their feed, twice daily, for 21 days each, following manufacturer’s recommendations. FlexAbility contained chondroitin sulfate, glucosamine, vitamin C, methyl sulfonyl methane, docosahexaenoic acid, eicosapentaenoic acid in a rice flour carrier with a vanilla flavor. Placebo contained only the inert rice flour carrier and vanilla flavor and was indistinguishable from FlexAbility. All horses received FlexAbility and placebo in a crossover design. All staff involved in feeding and handling the horses, and all people evaluating the horses were blinded to treatment. Horses were evaluated at day 0 (baseline), 21 (after first treatment) and 42 (after second treatment). Assessments included: clinical orthopedic evaluation for straight line/lunging circle in walk and trot; high-speed motion-capture determined hind limb motion for straight line trotting; grading of limb range-of-motion and muscle tone based on standardized physiotherapy criteria; handler grading of specific criteria during pasture, groundwork and ridden exercise. Effect of treatment, sequence, limb and interactions were analyzed using statistics.
- Horses fed FlexAbility had significantly lower grade lameness scores in a straight line and circle, with individual horses improving up to 2/10 grades over placebo/baseline (Table 1). For horses with hind limb lameness, FlexAbility was associated with significantly greater hock flexion than baseline (4.2% greater) or placebo (2.7% greater) (Table 2).
- FlexAbility was also associated with significantly improved limb range-of-motion and muscle tone and ridden/groundwork scores were significantly higher with FlexAbility compared to placebo/baseline.
- Horses fed FlexAbility were graded significantly higher for ‘ease-of-movement’ at pasture compared with placebo/baseline.
Take Home Message
- Feeding FlexAbility at the manufacturer recommended level was associated with less lameness, and improved physiotherapy scores, ridden/groundwork scores and pasture ‘ease-of-movement’.
- Increased mid-stance hock flexion of lame limbs may indicate improved mobility/comfort during peak loading, supporting a positive effect of the supplement.