LEVERAGING MOTOR CONTROL FOR EFFECTIVE SHOULDER REHABILITATION

– Written by Kathryn Fahy, Hercules Paquet, and Carla De Paula, Qatar

MOTOR CONTROL: DEFINITION

Motor control refers to the way the central nervous system (CNS) organises and coordinates muscles and joints to produce purposeful, efficient, and controlled movement. In the context of sports medicine, specifically in the shoulder, motor control refers to the ability to stabilise and guide glenohumeral and scapulothoracic movements with precision. It is not only a matter of muscular strength, but also of precise timing, sequencing, and coordination throughout the entire dynamic kinetic chain¹.

Overhead athletes such as swimmers, volleyball players, and pitchers depend on highly coordinated motor control patterns to maintain joint congruency and performance, especially during high-speed motions. Factors such as muscular imbalance or weakness, rotator cuff injury or related pain and arthralgia can often disrupt this control. Effective rehabilitation must therefore target motor control mechanisms to restore efficient muscle recruitment patterns to ensure optimal joint kinematics for return to sport. For example, executing a volleyball serve at high speed requires a kinetic chain action, where motor control integrates environmental perception, intrinsic motivation to move and adaptation to perturbations. (Figure 1).

BIOMECHANICS: FORCE COUPLES AND GLENOHUMERAL JOINT FORCES

The glenohumeral joint’s design favours mobility over stability, making it highly dependent on dynamic stabilisers and motor control to maintain joint centration under dynamic conditions. Glenohumeral contact forces (GHCFs) are the balancing act on which we strive to achieve the optimal, stable and mobile shoulder joint. GHCFs aim to achieve stability through balancing compressive forces (rotator cuff – deltoid force couple) that press the humeral head into the glenoid labral concavity (Figure 2), and shear forces (anterior -posterior, inferior – superior) that destabilise the joint by translating the humeral head towards the glenoid rim (Figure 3). It is the ratio of these force components that determines the risk of joint subluxation and subsequent loading of the capsulo-ligamentous labral complex². For example, the anterior-posterior balancing of the subscapularis (anterior) and infraspinatus/teres minor (posterior) is essential in balancing these forces.

During overhead activities, shear forces can rise substantially, sometimes exceeding 50% of compressive forces, especially at end-range positions. Motor control ensures that stabilising muscles activate in a synergistic and timely manner to maintain alignment at these demanding ranges. For example, in a volleyball jump serve position, motor control of the peri-scapula muscles and posterior rotator cuff provides the necessary compressive force to counteract the large anterior shearing loads produced.

PAIN, INHIBITION, AND MUSCLE COMPENSATION

After shoulder injury, pain and inflammation may reflexively inhibit certain muscle groups (arthrogenic muscle inhibition) while simultaneously causing overactivation of others as a protective strategy (inhibition of the supraspinatus may be compensated by overuse of the upper trapezius). This ‘muscle imbalance’ is a protective strategy by the CNS as it redistributes activity among muscles to protect the injured tissue³. Although initially protective, such adaptations under increasing load can lead to abnormal kinematics and altered joint stress and load. Motor control exercises (MCE) aim to reverse these compensatory patterns by restoring correct muscle activation sequences, often through low-load, precision-focused exercises with the aim of restoring optimal joint kinematics.

ASSESSMENT OF MOTOR CONTROL AND MOVEMENT INTEGRATION

While no gold standard for motor control assessment exists, clinicians must ensure a step-wise evaluation process and standardise testing, evaluating both static and dynamic movement patterns should be performed. Tests such as the Scapular Dyskinesis Test or Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) provide further insights into control deficits, while more sophisticated tools, like EMG or motion analysis, can quantify these deficits with greater precision^4,5.

However, it is important to consider that often the impairment has multiple contributing factors and should not be assessed solely through a pathoanatomical lens. A comprehensive clinical exam using clinician experience, the best available evidence and the use of qualitative assessment methods should prioritise enhancing motor control rather than focusing exclusively on isolated strength.

Motor control integrates both feedforward (anticipatory) and feedback (reactive) mechanisms. For athletes, this dual integration enables them to adapt in real-time to changing loads, environmental constraints, and fatigue. Task specificity is critical to retrain neuromuscular coordination, and this needs to begin as early as possible in the rehabilitation journey⁶. Effective rehabilitation should progress from low-load, motor-controlled drills to high-load, high-speed sport-specific patterns.

THE ROLE (IF ANY) OF MOTOR CONTROL IN EFFECTIVE SHOULDER REHABILITATION

Regardless of the primary management strategy—be it surgical intervention, pharmacological treatment, or conservative rehabilitation—clinical practice guidelines and systematic reviews consistently endorse exercise therapy as a cornerstone in managing both acute and overuse shoulder conditions⁷. This therapeutic approach typically encompasses a combination of motor control and strengthening exercises, aiming to mitigate pain and restore optimal shoulder function. Motor control exercises (MCEs) are used to facilitate movement that may be impeded by pain inhibition, muscle guarding and kinesiophobia⁸. This is pivotal in addressing motor dysfunctions that often contribute to shoulder pain and instability. In the context of shoulder rehabilitation, this involves retraining the neuromuscular system through enhanced coordination, timing and muscle recruitment patterns of the shoulder musculature. Addressing motor control provides the foundation for the shoulder to move optimally through range and progress to strength, power and more complex sports-specific movement patterns.

Rehabilitating the athletic shoulder is both a science and an art. We understand from our definition of motor control that the biomechanical rationale (science) is that balanced muscle forces protect the joint from excessive shear. The art comes in your clinical rationale to be able to identify this imbalance, target this specifically rather than globally and most importantly, tailor these principles to each athlete. Historically, shoulder rehab often emphasises the assessment and restoration of range of motion and strength, but less on how the athlete moves. However, motor control has gained interest in the past decade, adding a focus on the quality of movement, ensuring the right muscles recruit at the right time to stabilise the joint. Research to date has focused on the efficacy of MCEs in shoulder rehabilitation, particularly for rotator cuff-related shoulder pain^8,9 and shoulder impingement presentations¹⁰, with some promising results around pain reduction and functional improvements with a 10-week scapular motor control program. It is proposed that more optimal muscle activation and scapular positioning facilitate smooth coordinated movement through a reorganisation of movement patterns (quicker engagement of serratus anterior and lower traps). Additionally, a systematic review by Lafrance et al. (2021)⁹ highlighted that MCEs led to statistically significant reductions in pain and disability among adults with musculoskeletal disorders, including shoulder conditions, when compared to strengthening exercises alone. These findings underscore the potential of MCEs in enhancing rehabilitation outcomes and support the integration of MCEs as a facet of the overall shoulder rehabilitation program.

Finding the appropriate entry point for retraining specific patterns may result in a reversal in pain-induced inhibition and reduced muscle guarding. For example, teaching a rotator cuff-related shoulder pain patient to tolerate low-load external rotation with proper scapular kinematics may help to decrease reliance on compensatory shoulder hiking. The output of this approach induces neural plasticity to re-pattern normal movement in an efficient and pain-free function. This finding correlates closely with clinical experience and aligns with the importance of improving the neuromuscular control of the shoulder to reduce pain early and enhance the overall shoulder function for early progression to strength. Additionally, patients often report that motor-control-based rehab gives them a sense of stability and pain-free motion that facilitates confidence in the shoulder, setting the scene for progression to more loaded and sports-specific patterns.

In sum, restoring motor control in athletic shoulder rehabilitation is not simply about strength but about retraining the nervous system to generate safe, efficient, and sport-ready movement patterns. In doing so, we help athletes not only recover but also regain confidence and precision in motion.

EXECUTING MOTOR CONTROL FOR YOUR ATHLETE. THE GOOD, THE BAD AND THE UGLY. WHAT ARE WE MISSING?

While emerging research is trending towards the inclusion of motor control exercises as part of the rehabilitation continuum, more studies are needed to pinpoint the specifics of the intervention that will help us yield the best long-term results in our athletes. Are there optimal “doses” of motor control training for shoulders (analogous to strength sets/reps)? How can we better quantify deficits and thus improvements in movement quality objectively? Cumulatively, this results in significant gaps in progression to and execution of return-to-play criteria as we still lack granular guidelines on what constitutes sufficient dynamic stability for safe progression and eventual return to sport. In the meantime, using a combination of clinical assessment of functional movement (active versus passive) and executing smooth coordinated control, especially under conditions of fatigue, is the prudent approach. Applying this principle in a systematic approach to movements in isolated planes before progressing to multi-planar sports-specific patterned movements may help to simplify and quantify your approach.

APPLICATION TO OVERHEAD SPORT: THE VOLLEYBALL SERVE

Let’s return to executing a volleyball serve. During the serve, the athlete must generate power through a coordinated kinetic chain while maintaining precise shoulder control through rapid shoulder flexion and external rotation (Figure 1). Any disruption to this finely balanced muscle-coordinated pattern often ends in the athlete presenting with shoulder pain due to unbalanced loads and stresses on the glenohumeral joint.

In an athlete experiencing shoulder pain, a flexion or external rotation lag is often present. Clinicians must determine whether the limitation stems from stiffness, weakness, instability, or a combination thereof.  In a high proportion of cases with athletes presenting with shoulder pain, weakness tends to be the limiting factor. As a clinician, the pertinent question often is, did or is the pain causing the range deficit, or was it the range deficit that led to the pain? This range lag is identified when the active range in either flexion or external rotation is reduced (again, we don’t have a quantifiable % of how much) compared to the passive range available (Figure 4). This deficit is often due to poor posterior cuff activation/strength and/or scapular compensation, causing unbalanced forces and the inability to centralise the humeral head in the glenoid fossa. This imbalance often culminates in a disruption to the muscle activation timing, reduced velocity and power, and may increase stress on passive stabilisers like the posterior labrum.

By retraining motor control through visual feedback, rhythmic cues (e.g., metronome), and targeted posterior cuff activation, athletes can refine movement precision and build a shoulder capable of withstanding the repetitive high-load demands of elite-level serving. This begins with isolated sagittal plane flexion patterns combined with posterior cuff activation to facilitate a centred humeral head at end-range flexion. It is imperative that clinicians focus on how the exercise is executed before focusing on the prescription of the exercise.  These exercises can begin in a short lever position (Exercise 1) with the use of a band around the wrists to facilitate and cue posterior cuff engagement before moving to longer lever positions (Exercise 2) that are more demanding on the motor control of the joint.

 Substitution patterns, such as scapular elevation or retraction, often indicate an inability to isolate glenohumeral external rotation at end-range flexion. Limiting scapular assistance is essential to accurately assess motor control and detect any flexion lag. Isolated singular plane flexion exercises are vital in the early stage of motor control and can be complemented with isolated external rotation exercises. Often, external rotation positions are easier to identify weaknesses and gain buy-in from the athlete to address these deficits. As clinicians, we are often responsible for progressing passed isolated plane exercises such as Exercise 3 and Exercise 4 prematurely in search of more demanding multiplanar patterns. Smooth, controlled and full range (active v passive within 10%) with up to 2% body weight should be performed to fatigue before searching for more demanding tasks for the glenohumeral joint.

Once a full, smooth, and coordinated active range of motion has been restored, the next step is to challenge motor precision. Visual feedback tools—such as lasers used to trace ER/IR arcs—can improve accuracy and motor planning. Adding a metronome introduces temporal regulation, encouraging rhythm, precision, and gradually increasing movement speed.

CONCLUSION: BUILDING A SHOULDER THAT’S STRONG, STABLE, AND SMART

By integrating motor control principles—starting early with gentle co-contraction exercises, single to multi-planar movements, progressing through sport-specific retraining, and addressing psychological components such as fear of movement—rehabilitation becomes more comprehensive and effective. Athletes often not only recover but develop enhanced shoulder awareness, understanding and control in their highly demanding tasks. As an overhead athlete once described, “I feel like I’ve learned how to use my shoulder the right way”. This encapsulates the goal of motor control rehabilitation: building a shoulder that is not just pain-free, but prepared for the complex, high-speed demands of sport. Motor control strives to provide the foundation on which strength, power and speed can be layered upon.

Precision in motion is not just a philosophy—it’s a strategy for long-term performance and resilience. Clinicians should tailor motor control exercises to the athlete’s sport, considering factors like joint loading and movement specificity. Education and athlete’s understanding of appropriate movement patterns is essential to prevent compensatory strategies and movements into patterns of least resistance. Athletes treated with this approach not only heal but also often move better than before, according to their perception. They gain a heightened awareness and control of their shoulder mechanics, returning them to their sport with a reduced chance of re-injury. 

Kathryn Fahy PhD

Physiotherapist

Hercules Paquet

Physiotherapist

Carla De Paula

Physiotherapist

Aspetar Orthopaedic and Sports Medicine Hospital

​Doha, Qatar

Contact: kathryn.fahy@aspetar.com

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