by Nadia Kopec, Gillian Tabor and Jane Williams

Introduction

Canine research supports using steps and ramps within therapeutic rehabilitation after orthopaedic or neurological injury and surgery. However, there are gaps in the research to support their effects and application. Ascending steps or ramps increases shoulder, elbow, carpus, hip, stifle and tarsus joint range of movement and strengthens the muscles used to propel the animal forwards and upwards [1,3]. Physics tells us that what goes up must come down, so understanding the biomechanical impact of descending steps or a ramp as part of a canine rehabilitation regime is vital to ensure the exercise prescription is accurate and effective whilst ensuring evidence based practice. As well as increasing joint range of movement, step and ramp exercises also challenge balance and proprioception [4] making them useful for treating different conditions at varying stages of rehabilitation. Step exercises are also functional as many dogs encounter steps as part of daily living and are accessible to owners, making the regime specific to returning to normal function. The biggest benefit of steps as an exercise is that no expensive equipment is required and most people can fit them into their normal daily routine (as long as they have suitable stairs available to use).

Investigation of steps and ramps in canine exercise regimes

Figure 1 – Shoulder extension in the left forelimb when reaching for next step.

Thus far the canine kinematics (the study of motion) whilst ascending steps and a ramp of the forelimb [1] and hind limb [3] have been investigated. Hind limb movement has also been studied whilst descending ramp and steps [2], leaving a gap in the current evidence. To add to the existing research in this area, a study of the forelimb in non-lame dogs descending steps and a ramp was completed. The study used a two-dimensional kinematic motion analysis system to assess canine kinematics in the forelimb of eight dogs, weighing 21-24.7kg (mean 22.3kg +/-1.9kg), aged 3-9 years (mean 5.5 years +/-2.7years). The sample consisted of six bitches and two dogs, seven neutered and one unneutered female of varying breeds. Flexion, extension and total range of movement of the shoulder, elbow and carpus were assessed whilst descending steps, a ramp with a 35° angle and trotting on the flat. The motion during each were compared. The speed and stride lengths of the dogs were also measured during each of these conditions.

Significant increases were found in shoulder and elbow range of movement and elbow flexion when descending steps compared to descending the ramp and trotting on the flat (P<0.016). However, elbow extension was significantly greater when trotting on the flat compared to descending steps and a ramp (P<0.016). Stride length was significantly greater in trot on the flat compared to when dogs descended the ramp (P<0.016). No significant differences were found in speed for any dogs between the three measurement conditions.

Figure 2 – Shoulder flexion in the left forelimb as the right forelimb reaches for the next step which lowers the body towards next step.

Changes in shoulder range of movement when descending steps were attributed to the increased limb length and therefore shoulder extension required to stretch down to the next step (Figure 1). The limb length increases relative to its length in standing, due to the extension of the joints in the upper limb. At this point during the movement, the opposite shoulder has to flex to allow the body to lower to accommodate for the dimensions of the steps to enable descent (Figure 2).

The increase in elbow range of movement and flexion correspond with relative shortening of the limb to clear the step-edge during the swing phase of gait (Figure 3). Elbow extension however was limited on the steps by the previous step-riser as shown in Figure 4, but removing this limitation when trotting on the flat, allowed greater elbow extension and a larger stride length (Figure 5).

There was no significant increase in carpus range of movement seen when descending steps or a ramp compared to trotting in the flat. This was explained by the carpus flexing to clear the floor when trotting on the flat but when descending steps or a ramp, no additional movement was required due to the decline in the surface and limb length being changed mainly at the elbow.

Figure 3 – Elbow flexion in the left forelimb, to clear step edge.

When ascending and descending steps or a ramp, the dog must transfer weight to alternate forelimbs or hindlimbs. The leg in stance must balance and support the body whilst the other leg goes through a larger range of movement and also the brain must know where the foot is in space (proprioception) in order to clear the step edge or surface of the ramp. The control of this considerable weight shift from side to side may explain the reduced speed of the dogs when completing stairs and a ramp compared to when trotting on the flat. This was also seen in another study [4] looking at the kinematics of the limbs during walking exercises and these authors also suggest this is due to the challenges placed on proprioception and balance. This must be considered when giving this exercise as part of an early rehabilitation programme as it could become too challenging for some animals if prescribed too soon.

When ascending, the limb must propel the animal up, but during descent, the braking role of the forelimbs is increased and therefore eccentric contractions would occur and so should increase strength [5]. However, the stage of rehabilitation and strength of the muscles being worked should be assessed as eccentric contractions can be considered negative work due to the muscle absorbing energy as it is in a loaded position which can place too much force on weak muscles [6]. Eccentric contractions, where the muscles are lengthening and controlling the lowering of the body, use less energy, even though they create more force than concentric actions. Although stride length was not significantly different between the three conditions, the stride length when descending the steps was far more consistent than that on the ramp and flat surface. Due to this finding it may be preferable to use the steps as part of a home exercise programme as it is more likely to be accurately reproduced and may also be easier to recreate at home.

Practical implications for canine physiotherapy

Figure 4 – Elbow Extension in the left forelimb, limited by previous step riser.

The results of this study show that the use of descending steps as an exercise for therapy has the potential to improve the range of movement of the shoulder and elbow of the canine forelimb when compared to trotting on the flat. In early rehabilitation of a forelimb issue, descending steps and a ramp may be useful to increase range of movement of the shoulder and elbow. However it may place too much strain on the weak or healing muscles due to the eccentric contractions required to aid braking, so strength and control need to be thoroughly assessed to ensure appropriateness for this exercise. Once the animal is confidently weight bearing and gaining strength, descending steps could give added strengthening element to a home exercise programme as well as challenging balance, control and proprioception. Descending a ramp can also be useful for elbow exercises but may not be as consistent as steps and may be harder to reproduce in a home exercise programme. Where additional support or guidance is required, for example in a neurological injury with reduced proprioception, steps and ramps may not be possible to reproduce correctly in a home exercise programme due to availability of people and appropriate handling.

Other than in a clinical scenario, the angle of this ramp may be hard to replicate and therefore the use of steps would be recommended. The dog needs to stay calm and straight on the equipment during these exercises and therefore may not be suitable for all dogs. The steps exercises would be easier to control than the ramp as the stride length is defined by the dimensions of the steps whereas the dogs can alter stride length on the ramp. The exercises would have to be regularly reviewed by the therapist to ensure the correct effects were occurring and exercises were consistent [4]. A good explanation, instructions and demonstration where possible, would be recommended when being used as part of a home exercise programme. The dogs in this study required minimal acclimatisation but once the dog became confident, some of them attempted to jump down the ramp or missed out steps. Owners would need to have sufficient control of the dog in order for these exercises to be effective and not put the dog at risk. All exercises included in any home based therapeutic regime should be practiced, demonstrated and trialled with the owner to ensure the exercises are appropriate, performed correctly and consistently.

Figure 5 – Elbow extension reaches for the next step which lowers the body towards next step.

If a dog requires adaptations to the home environment in order to avoid extremes of movement, the results of this study would suggest that descent of a ramp would be preferable to steps as the limb performs significantly less range of movement, particularly at the elbow. Such exercises can be used in the rehabilitation of orthopaedic and neurological disorders as well as postoperatively, but must only be used at the correct stage of rehabilitation to avoid injury or detrimental effects. Post-operative instructions and contraindications should be considered prior to their use and each dog should be assessed and trialled with the exercises to ensure they are appropriate. No research has yet studied the effects of these exercises on lame dogs, therefore they should be used carefully if a dog is not sound as they will increase the weight bearing on the affected limbs during the stance phase which may not be appropriate. However, where an increase in weight bearing is a desired effect, then descending steps or a ramp would increase the weight and forces placed on the forelimb [5]. These exercises may also be used to improve balance, motor control, proprioception and limb placement. The eccentric work of the forelimb muscles whilst performing the role of braking in descent could also be used as a strengthening exercise.

Conclusions

When formulating a rehabilitation programme, with the aim to increase forelimb joint range of movement, the use of stair and ramp descent exercises should be considered. The results from this study show that the use of stair and ramp descent exercises could have therapeutic value within a rehabilitation programme. The benefits of these exercises can now be compared to those of other therapeutic exercises and assist with evidence based decisions to ensure that the exercise regime is as accurate and effective as possible. Step descent as a therapeutic exercise would assist with increasing range of movement of the shoulder and elbow and may be useful in recovery from surgery or after orthopaedic or neurological injury. Other effects of these exercises such as balance, proprioception and strengthening may also occur but require further investigation. Step exercises are more likely to be a consistent and reliable method of increasing range of movement as the ramp and trotting exercises are harder to control and monitor to ensure the correct effects are occurring. Steps are therefore more suitable for a home exercise programme where a therapist is not present. It is essential that all exercises need to be assessed as appropriate for the particular client and owner as well as the stage rehabilitation.

BIOGRAPHY

Nadia Kopec

Nadia is a Chartered Physiotherapist and an ACPAT physiotherapist having graduated with an Msc in Veterinary Physiotherapy from Hartpury College in June 2015. Nadia started up NKVetPhysio providing physiotherapy for horses, dogs and cats and The Mobility Physio for treatment of humans two years ago. Nadia won the ACPAT prize when graduating after completing the above mentioned research as part of her MSc degree. Gillian Tabor and Jane Williams were Nadia’s dissertation supervisors during this process. Nadia is keen to promote evidence based practice and wants to continue to complete research.

Nadia has owned and competed her own horses and dogs since the age of eight years old and therefore understands that whether they are pets or an athlete, they still mean the world to their owners. Nadia has experienced firsthand the importance of correct rehabilitation after an injury of an animal and therefore understands how it feels for an owner as well as seeing how good practice can be very effective.

Gillian Tabor

Gillian is a Chartered Physiotherapist who has been working as an ACPAT Veterinary Physiotherapist for over 15 years. In her own practice in Devon she specialises in physio for horses and riders, with the focus on treatment and rehabilitation of competition horses. Gillian is the programme manager and lectures on the MSc Veterinary Physiotherapy course at University Centre, Hartpury and is undertaking research, both her own equine projects and supervising students. When not working she has two young Lusitanos to keep her busy and plans to progress up the dressage levels with them.

Jane Williams

Jane is an experienced researcher, with a passion for enhancing animal performance and welfare through teaching and industry informed realworld research, which generates change. Jane is a qualified veterinary nurse and gained her Masters in Equine Science before completing her doctorate exploring the application of surface electromyography (EMG) as a tool to assess muscle adaptation during training in racehorses and sport horses. Her main areas of professional interest include scientific evaluation of animal performance and training and reliability assessment.