Is It Time to Put ‘Rest’ to Bed?

While prolonged rest and immobilisation formed the cornerstone of recovery from injuries and surgical interventions in the past, in recent years we have seen an intentional shift towards early mobilisation and progressive loading within the veterinary rehabilitation industry.

Early mobilisation and progressive loading led by functional healing milestones as opposed to strict timelines, allows us to stimulate effective healing and tissue adaptation within the musculoskeletal and nervous system to return a patient to optimal function. Instead of replacing rest and tissue protection, early mobilisation should instead intertwine with and balance out principles of protection in our patients.

Let’s further explore these concepts.

From Immobilisation to Optimal Loading

In human sports medicine and rehabilitation, we’ve seen a shift from the traditional RICE principles (Rest, Ice, Compression, Elevation) to POLICE (Protection, Optimal Loading, Ice, Compression and Elevation), and finally to the introduction of PEACE & LOVE (Protect, Elevate, Avoid NSAIDs, Compress, Educate in the acute phase, and Load, Optimism, Vascularisation and Exercise for subsequent management). These principles highlight that while protection is important initially, intentional and progressive loading forms an important part of the healing process, instead of following after healing has already occurred (Bleakley et al., 2012; Dubois & Esculier, 2020).

Optimal loading is not unrestricted activity – and this distinction is important for us to recognise in rehabilitation. Early loading does not replace protection of the injured site. Instead, it introduces an appropriate mechanical stimulus that can support tissue repair, vascularisation, fluid movement and the gradual restoration of function. Safe, progressive loading walks hand in hand with the protection of healing and compromised tissue (Khan & Scott, 2009).

The challenge for Vetrehabbers is therefore not simply to prioritise either rest or exercise, but to balance protection and progressive loading according to the biological capacity of the healing tissue.

Tissue Healing: Milestones, Not Timeframes

Although each tissue follows broadly predictable biological stages of healing, the inflammatory, reparative and remodelling phases are dynamic, overlapping processes that continually respond to the local environment and the mechanical loading placed upon the tissue (Shaw & Martin, 2016).

While tissue healing follows broadly predictable biological stages, the rate and expression of healing vary between tissues and individual patients. Mechanical loading is one of the most powerful ways we can influence this process, allowing us to stimulate changes in collagen production, tissue organisation and structural adaptation (Khan & Scott, 2009; Wang, 2006). Appropriate loading therefore is more than simply rebuilding strength, instead it provides a biological signal that helps direct optimal tissue repair.

Patient factors including age, systemic health, conditioning, concurrent disease, nutrition, conformation and biomechanics influence the rate and quality of healing. Rehabilitation must therefore remain individualised.

In her podcast, Milestones, Not Timeframes, Gillian Tabor encourages clinicians to progress rehabilitation according to the patient’s functional capacity rather than the calendar alone. Time remains biologically relevant, but progression should also reflect measurable changes in pain, loading tolerance, movement quality, strength and function.

Detrimental Effects of Immobilisation: The Cost of Rest

Rest undoubtedly has a place within healing and rehabilitation. Unstable fractures, surgical repair sites, severe tissue injury – all require protection that comes from a restriction of movement or control of use to allow healing to occur.

Prolonged immobilisation, however, affects more than just the injured structure.

The musculoskeletal system is incredibly adaptable, allowing it to respond to load – or the lack thereof. When we remove stress from the body, muscle atrophy develops rapidly, strength declines, cardiovascular fitness reduces, bone density decreases, tendon stiffness changes, and joints become less tolerant of movement. These changes can begin within days of reduced activity and become increasingly difficult to reverse as periods of immobilisation lengthen (Dirks et al., 2016).

Adaptation isn’t restricted to the musculoskeletal system either – reduced physical activity has been associated with increased systemic inflammation, insulin resistance, poorer metabolic health, altered pain processing and reduced psychological wellbeing (Pedersen & Saltin, 2015). Many of our patients already lead relatively sedentary lifestyles before injury. For these individuals, extended periods of crate or stable rest may compound existing deficits in muscle mass, proprioception, cardiovascular capacity and overall function.

Rehabilitation therefore extends beyond protecting damaged tissues – it aims to preserve the health of the entire patient while those tissues recover. The goal is not to eliminate rest, but to minimise unnecessary immobilisation wherever it is safe and appropriate to do so.

Shaping the Nervous System

One of the most exciting developments in rehabilitation over the past decade has been the increasing recognition of the nervous system’s role in recovery. While rehabilitation has traditionally focused on healing the musculoskeletal system, we now understand that every rehabilitation programme is also shaping the brain and nervous system. This makes the discussion around rest, immobilisation and progressive loading even more important.

Acute pain serves an essential protective function immediately following injury. It encourages us to reduce movement, protecting damaged tissues while the initial stages of healing take place. However, pain can become maladaptive surprisingly quickly. As healing progresses, pain may become less closely related to the state of the tissues and increasingly influenced by sensitisation, previous experiences, context and changes in nervous-system processing. When this occurs, persistent pain can become a barrier to recovery, contributing to ongoing movement avoidance, muscle weakness, altered movement patterns and loss of function. Carefully prescribed movement and progressive loading can form part of a broader strategy to modulate pain, rebuild confidence and restore function (Nijs et al., 2015).

The nervous system follows the simple principle of use it or lose it. Neural pathways and functions that are repeatedly recruited can become more efficient, while those that are not used may weaken. Kleim and Jones (2008) describe experience-dependent plasticity as a process shaped by use, repetition, intensity and the specificity of training. During rehabilitation, the movements we practise – and the compensations we repeatedly allow – can therefore influence the patterns that become reinforced.

If an injured limb is consistently protected beyond what is biologically necessary, the nervous system becomes increasingly efficient at avoiding its use. Altered movement patterns, compensations and protective behaviours become reinforced, making them progressively more difficult to reverse. Conversely, carefully controlled loading provides the nervous system with meaningful sensory input that reinforces normal movement patterns, restores confidence in using the affected limb and helps prevent these maladaptive adaptations from becoming established.

This does not mean pushing patients through pain or abandoning necessary periods of protection. Instead, it reinforces the importance of introducing safe, appropriate movement as early as tissue healing allows. Rehabilitation is not simply rebuilding tissues – it is continually teaching the nervous system how we want the patient to move.

Conclusion

The shift away from prolonged immobilisation does not mean that rest and protection no longer have a place in rehabilitation. Instead, it challenges us to be more intentional about how long we restrict movement, when we begin introducing load, and how we progress that load according to the needs of the individual patient.

Early mobilisation may begin with something as simple as supported weight bearing, controlled walking, gentle joint movement or low-level muscle activation. The appropriate starting point will differ according to the tissue involved, the stability of the injury or surgical site, the patient’s pain response and their functional ability.

Ultimately, effective rehabilitation is not about choosing between rest and exercise. It is about balancing protection with progressive, purposeful loading so that healing tissues – and the nervous system controlling them – are given the opportunity to adapt, strengthen and return to function.

References

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