Koper Equine

Exercise resistance in horses with PSSM2-ER (Polysaccharide Storage Myopathy Type 2/*Muscle Integrity Myopathy (MIM), – Exertional Rhabdomyolysis) typically manifests as a reluctance or inability to perform physical activities that require muscle effort, particularly exercise that is more intense or sustained. Here’s how this condition contributes to exercise resistance:

1. Muscle Pain and Stiffness:

• Manifestation: Horses with PSSM2-ER experience muscle pain and stiffness after exercise due to abnormal glycogen storage and energy metabolism. This can cause discomfort or soreness, making the horse reluctant to continue working or perform tasks that involve prolonged or strenuous activity.

• Exercise Resistance: As muscle cells are unable to properly store or utilize glycogen, they become damaged during exercise. This results in muscle pain, cramps, or even spasms, leading to resistance to exercise, especially when the horse anticipates discomfort.

2. Fatigue:

• Manifestation: Horses with PSSM2-ER may tire more quickly than healthy horses due to the inefficient energy production in their muscle cells. This fatigue is a direct result of their muscles’ inability to efficiently metabolize glycogen and produce ATP (adenosine triphosphate) for muscle function.

• Exercise Resistance: Fatigue sets in sooner, and the horse may stop moving or refuse to perform tasks, especially if exercise is prolonged or of high intensity. The horse may become more easily winded and show reduced stamina.

3. Muscle Weakness:

• Manifestation: Chronic issues with muscle metabolism can lead to muscle weakness, further contributing to exercise resistance. The horse may be reluctant to move or may show difficulty with activities such as cantering, trotting, or jumping.

• Exercise Resistance: Weakness may be particularly apparent in the rear limbs or in movements that require coordination, as the muscles are not working at full capacity. The horse may exhibit lameness or uneven gait, leading to avoidance of activities that put strain on these areas.

4. Cramping and Tying-Up Episodes:

• Manifestation: Horses with PSSM2-ER are prone to tying-up, a condition where muscle cramps become severe and painful, often after exercise. This can be caused by the accumulation of abnormal glycogen in the muscles.

• Exercise Resistance: After experiencing tying-up episodes, the horse may develop a reluctance to engage in physical activity, as they associate exercise with pain and cramping. They may resist moving or refuse to work, especially under conditions that could trigger another episode.

5. Behavioral Changes:

• Manifestation: As the horse experiences pain, discomfort, or frustration due to their muscle issues, they may develop behavioral changes like irritability, unwillingness to cooperate, or anxiety related to exercise.

• Exercise Resistance: These behavioral changes may manifest as avoidance tactics, such as balking, rearing, or refusing to work. The horse may not show the usual willingness to perform tasks, particularly when they associate exercise with pain or stress.

How Massage and Stretching Help

Massage, stretching and micro-movements can be powerful tools in managing the symptoms of PSSM2-ER and reducing exercise resistance by improving muscle function and reducing discomfort:

1. Improving Circulation and Reducing Muscle Tension:

• Massage: Gentle massage can help promote blood flow to the affected muscles, which may improve the delivery of oxygen and nutrients while helping remove metabolic waste products. This can ease tension, reduce stiffness, and improve the overall flexibility and comfort of the horse.

• Stretching: Regular gentle stretching can help maintain flexibility, especially in the affected muscle groups. This is essential in preventing further stiffness and muscle shortening, both of which can worsen exercise resistance.

• Micro-movements: Micro-movements are subtle, small-range movements that target deeper muscle layers, fascia, and joints. These movements can be incredibly valuable for reducing fascial adhesions, improving or maintaining joint mobility, reducing pain and gently relaxing muscles.

2. Reducing Pain and Inflammation:

• Massage: Massage therapy can alleviate muscle soreness and discomfort by reducing inflammation in affected muscles. A reduction in pain can make it easier for the horse to tolerate exercise and movement.

• Stretching: Stretching can also help with pain reduction by gently lengthening muscles, improving their range of motion, and preventing further tightness and cramping.

Micro-movements: Micro-movements are highly effective for alleviating pain and inflammation by reducing fascial adhesions, enhancing joint mobility, and gently relaxing muscles. These small, controlled movements help promote circulation, decrease tension, and support the natural healing processes, contributing to pain relief and reduced inflammation.

3. Managing Stress and Behavioral Issues:

• Massage: Regular massage can have a calming effect on the horse, helping to reduce anxiety or stress, which can sometimes contribute to resistance to exercise. By promoting relaxation, massage can help the horse approach exercise with less fear or reluctance.

• Stretching: A regular stretching routine can also help reduce behavioral tension. If the horse experiences less discomfort, they may be more inclined to perform activities without showing resistance.

• Micro-movements can be highly beneficial for managing stress and behavioral issues by promoting relaxation, improving body awareness, and reducing fascial tension. These gentle movements help to release accumulated stress in the body, foster a sense of calm, and improve overall well-being, which can positively impact behavior and emotional responses.

4. Supporting Muscle Recovery:

• Massage: Massage can promote faster muscle recovery post-exercise by reducing muscle tightness and promoting tissue repair. This recovery support can help prevent the onset of pain or stiffness after exercise, allowing the horse to be more comfortable with future sessions.

• Stretching: Incorporating stretching into post-exercise routines can help prevent muscle cramping and tightness, facilitating smoother transitions from high-intensity activity back to rest.

• Micro-movements help support muscle recovery by promoting circulation, reducing fascial adhesions, and enhancing joint mobility. These gentle movements help alleviate muscle stiffness, improve flexibility, and reduce pain, allowing muscles to recover more efficiently after exercise or injury.

5. Preventing Tying-Up Episodes:

• Massage, Stretching and Micro-Movements: Massage, stretching and micro-movements can help prevent episodes of tying-up by improving muscle flexibility, preventing lactic acid buildup, and reducing muscle fatigue. By addressing tension and cramping before they start, these therapies can help reduce the likelihood of a tying-up episode and improve exercise tolerance.

Conclusion

For horses diagnosed with PSSM2-ER, massage, stretching and micro-movements can play an essential role in managing exercise resistance by supporting muscle function, reducing discomfort, and promoting relaxation. A well-planned approach to bodywork therapy, including massage, stretching and mico-movement routines tailored to each horse’s needs, can improve their willingness to exercise, reduce pain, and support overall well-being. As always, any therapy should be done under the guidance of a veterinarian and an experienced equine therapist to ensure it aligns with the horse’s unique health needs.

* PSSM2 (Polysaccharide Storage Myopathy Type 2), has been reclassified and is now referred to as Muscle Integrity Myopathy (MIM). This change reflects a deeper understanding of the condition, which involves disruptions in muscle structure and function rather than issues with polysaccharide storage. MIM encompasses various genetic variants, including P2, P3, P4, P8, Px, and K1, each affecting different aspects of muscle integrity.