Rehabilitation of Back Problems: Training and Management

I. Introduction

Horses in training are subject to progressive dorsal and vertebral axis causes of pain. Most of these diseases are related to pain with muscle spasms, neurologic disorders, and potential joint or bone pathologies. The type of discipline and work load can lead to such problems depending on preexisting issues and management of the horse itself. There are many parameters which make the anamnesis of such pathology difficult, and this paper will describe which are the most significant.

II. Clinical evaluation

Clinical evaluation should be done even if the patient was recently examined by a practitioner. The purpose is to see what sore spots and what defects of back mobilization can be identified before starting a rehabilitation protocol.

Static Exam

This part of the exam is done in a quiet place, ideally the stall. The horse should be standing so that the practitioner can assess limb position and weight bearing. A superficial palpation is performed with the palm of the hand, then deeper structures are palpated with the fingers. Mobilization with lateroflexion and longitudinal extension/flexion of the long axis should be done to assess range of motion of each segment. Passive tests on the spinous processes, sacrum, and flexion/extension tests are done on all 4 limbs to evaluate the level of distal joint motion and whether any pain is evident during manipulations. A rectal exam is also conducted to check involvement of psoas muscles and other local structures in back pain or abnormal motion (This exam should be repeated every 15 days if the horse continues to show more lumbar region pain).

The practitioner should document his or her findings during the rehabilitation process. As a follow up, this should be completed by the rider or technician on a daily basis (for example, abnormal spasm, sensitive areas, or heat when preparing the horse, and abnormal stiffness or assymetry by the rider). The practitioner should reevaluate the horse weekly and check the findings recorded by the rider or technician at the same time. Any persistent pain noted by the rider/technician for more than 3 days should be reevaluated earlier by the veterinarian.

III. Techniques of rehabilitation

Movement

The first technique of rehabilitation of musculoskeletal disease is to obtain progressive movement and mobilization of the affected segments. There will always be a limit due to abnormal conformation or chronic disease, but the idea is to restore motion.

The clinical evaluation and previous diagnosis will give the practitioner an idea of the amplitude of motion that can be expected from a portion of the back which is sore, spastic or reluctant to move. At this stage, there should be a progressive warming up of these structures which will combine physiotherapy, work on longe line or under tack on the flat, and then a more specific type of exercise within the stress of the previous discipline.

Location of the Exam

During rehabilitation, this exam is done at the barn where the horse is staying or working so the practitioner can inspect the horse’s environment, potential stress and footing. If the exam is performed in the clinic, it can be tempting to see the horse only in hand and this will give the practitioner only part of an objective assessment.

The horse is first examined in hand especially on straight line and circles looking for abnormal bending (See Clinical Evaluation). Then, under tack evaluation should be performed so a dialog with the rider can be achieved. The rider and horse should be watched during the sitting/rising gaits to see how the horse’s back is moving with the rider’s weight, and during changes of lead.

Rehabilitation when the horse is cold may include the following:

• Technique of stretching exercises (with carrots for cervical and thoracic area for example) and passive lateroflexion of back and pelvis
• Massage/Hand stretching by groom (daily) or a qualified physiotherapist (2 to 3 times a week) when possible
• Work in hand with small longe line (walk forward/backward, and figure 8)
• Using a warm blanket, solarium, and hot packs
• Using electrical stimulation: Functional Electro Stimulation (FES)/Tense/Ultrasound/Vibromassage
• Using weighted boots around the pastern.
  Weight will affect the swing phase of the stride. Weight changes where the limb hits the ground. Proprioception and impact may change because the horse feels there is something on its leg. It will also "awaken" muscle spindle cells and Golgi organs as muscles change in tension and stretching with weight. There is an increase in hip, stifle, hock and ankle flexion on hind limbs with weight. Clayton reported on the effects of using five different types of stimulators on the hind legs. (Clayton and al. 2010 and 2011). Weighted hind boots influence the flight of the hind quarters over jumps (Murphy and al 2009). Up to 70% of riders use weighted boots at GrandePrix and Nations’ Cup jumper shows.

Rehabilitation when the horse is warming up may include the following:

• Use of longe line
  There are different techniques such as side reins (which may not limit overextension of the neck, and bit-related lever arm), Gogue (neck and bit lever arm), Chambon or Pessoa rig (which tends to prevent the hind quarters from ‘escaping’ to the outside of the circle.

• Use of different footing and slope
  Uphill work will enhance more engagement and promote contraction of the abdominal wall. Downhill work will be challenging for horses suffering from sacro-iliac joint disease, especially when the horse is cold. Deep footing will make the horse elevate its limbs more and require extra effort with the abdominal wall and upper limb muscles. Firmer footing tends to increase vibration and will be contraindicated for joint and bone disease when the horse is not warmed up (such as lower cervical, kissing spines, epaxial joint disease).

• Use of different type of work under tack
  There is an interest in finding the appropriate gait depending on the region of back problem:
  • Thoracic pain
    The horse is better to move freely on a longe line to warm up because they tend to counter bend when cold. Avoid any surcingle which may increase the longissimus muscles tension and enhance supraspinous ligament pain, or kissing spines issues. The choice of the saddle is paramount for this type of back issue. Small circles are not indicated when the horse is not warmed up.
  • Thoraco-lumbar (TL) and lumbar pain
    A long walk before jogging is preferable. Some horses feel better after cantering instead of trotting because there is less axial movement of the spinal column, especially for horses suffering from epiaxial joint disease. Using a warm rug to cover this area of the back is very important, especially in cold countries or seasons.
  • Lumbosacral (LS) and pelvic pain (sacroiliac (SI) 
    A long walk or walker before exercising is preferable. Half pass can be done when the horse tracks under tack sideways, but this should be done progressively to gradually obtain pelvis axial motion under tack. With lumbosacral pain (and sometimes TL junction pain), many horses prefer to canter after a long walk instead of trot, where the axial motion of the TL and LS space can be restricted.
    In this warming up phase, the horse should not do small circles because it creates a lot of stress on LS and SI junction. In case of discomfort on shorter circles, the horse will start to lean with its hind quarters more to the inside of the circle. A good exercise for this proper bending is to make concentric circles. The circles should become progressively smaller and the rider should keep a strong inside leg on the horse to encourage proper bend. Horses starting to lean inside on a smaller diameter circle should initially be worked on wider circles. The rider can play with circle size and length of stride to stimulate the flexion and pushing of the hind quarters.

Type of Physiotherapy Work

Many techniques exist to promote healing of a specific injury. This paper discussed the most common techniques used for back problems and their main indications will be reviewed.

• Massage
  This is the best technique so far with potential use in different ways to soften, or stimulate fascia and underneath muscles. Many massage techniques are available, but this would be the first modality to offer to owners and grooms working on their own horses.
• Laser
  Depending on the laser power, you could expect to affect healing only or to enhance cell metabolism on superficial wounds or fascia tears. Laser can also be used for trigger point stimulation. Deeper penetration laser units are now on the market but there are no scientific reports regarding higher power laser use for back problems in horses.
• Therapeutic ultrasound
  This will increase local blood flow and enable muscle relaxation, stimulation of trigger/myofascial pain points. This can also be used for hematomas, scar tissue, muscle spasm and local inflammation.
• Kinesiotaping
  A special tape is applied to limit movements of certain joints and activate certain proprioceptive functions. Kinesio Tape has the same elasticity as skin and can relax or strengthen muscles, support ligaments, stimulate circulation and decrease inflammation, depending upon how and where it’s applied. Some of these techniques can be used for acute or chronic spastic areas of the back, or local injuries.
• Electrotherapy
  • Transcutaneous electrical nerve stimulators (TENS)
    These tools can be used to decrease pain by changing how the nervous system responds to pain signals. In general, TENS units send electrical signals that confuse the pain pathways, blocking the sensation of pain. These systems are designed to stimulate only sensory nerves.
  • Interferential stimulators
    These units also are nerve stimulators, but each uses a pair of high-frequency waves that can penetrate deeper into the skin than TENS units. Therapists use these stimulators to treat patients with debilitating pain.
  • Neuromuscular and functional electrical stimulators (FES)
    These units use electrical waves to stimulate motor nerves (i.e., nerves that control muscles). Thus, neuromuscular stimulators offer a way to mobilize muscles and associated tendons and ligaments through controlled muscular contractions, which can be uncomfortable for the horse. Ultimately, the deep muscle contractions induced by these units reduce spasticity and associated pain in the stimulated muscles. Unlike the TENS and interferential stimulators, this pain relief is long-lasting.
  • Galvanic muscle stimulators
    These units use direct current to generate a very low-voltage electrical signal to be transmitted in one direction. Professionals use this type of stimulus mainly to transmit substances, such as medications, through the skin in a process known as iontophoresis.
  • Microcurrent electrical stimulators
    These units produce low-amplitude currents that mimic weak electrical currents produced during normal/natural tissue healing. Unlike TENS and neuromuscular electrical stimulators, these units do not stimulate sensory nerves or muscles, which means the patient feels no tingling.
• Light therapy (solarium, laser)
  This therapy promotes heat and local blood flow and is used to warm up chronic spasms on horses with chronic back stiffness before and after exercise.
• Shock wave
  Shock wave is used to stimulate trigger points or to treat myofascial pain. Back treatment can be done on longissimus and gluteus muscles for progressive relaxation. The horse is expected to have spasm relief within a few hours treatment may be effective for up to 15 days. Many horses that do not respond to the initial treatment may need a second treatment or may be a candidate for a different modality.
  Shock wave therapy is indicated for supraspinous ligament desmitis on the spinous processes, but the horse will also need rest.
• Magnetic field
  Magnetic field therapy enhances local vascularization. Depth of penetration is not well documented and depends of the unit power and intensity. Note that only a machine using battery power can be used on horses at FEI shows.
• Cryotherapy
  Anhydrous nitrogen is the most known technique and can create a good myofascial stimulation and relax sore superficial muscles by local stimulation.
• Hydrotherapy (water treadmill and swimming) 
  Water treadmill will help the horse develop strength and motion of the upper limb muscles without creating an overload response to the distal limb (if, for example, the horse has had concommitent surgery). Swimming may create potential overextenion of the back and is more commonly used in the author’s experience for more distal limb non-weight bearing rehabilitation rather than back problems.  [...]