CHAPTER 14: Improving Neuromuscular Control

CHAPTER OBJECTIVES

At the completion of this chapter, the reader will be able to:

1. Define the components of neuromuscular control.

2. Describe ways in which neuromuscular control can be improved.

3. Describe a number of exercises that can be used to improve proprioceptive control.

4. Provide examples to enhance balance retraining.

5. Explain the concepts related to stabilization retraining.

OVERVIEW

The entire rehabilitation process is focused on restoring function as quickly and as safely as possible. An important component of function is neuromuscular control. Neuromuscular control involves the detection, perception, and utilization of relevant sensory information in order to perform specific tasks (see Chapter 3). It is now well accepted that a neuromuscular control impairment can change normal movement patterns and increase the risk of musculoskeletal injury. Successful performance of a task requires the intricate coordination of various body parts using the information provided by peripheral receptors located in and around the articular structures. This feedback provides information that assists with proprioception, balance, and kinesthesia (see Chapter 3). In terms of segmental joint control and spinal posture and orientation, each joint in the kinetic chain must have the ability to maintain the optimal alignment, biomechanics, and/or control required for the task being performed. If there is a loss of optimal alignment, biomechanics, and/or control, this is defined as failed load transfer (FLT) at that joint.¹ While a single segmental loss of control often correlates with changes in posture orientation, multisegmental loss of control results in an inability to maintain the required spinal posture or orientation required for the task to be performed. The presence of a loss of segmental or multisegmental control involves an assessment of:

• whether there is adequate range of motion;

• whether there is sufficient strength output;

• whether there is the ability for automatic control of the joints in the kinetic chain that exhibit FLT;

• whether pain negatively impacts the performance of the task.

Neuromuscular rehabilitation (NMR) is a method of training used to enhance these unconscious motor responses, by stimulating both the afferent signals and the central mechanisms responsible for dynamic joint control.² The aims of NMR are to improve the ability of the nervous system to generate a fast and optimal muscle-firing pattern, to increase joint stability, to decrease joint forces, and to relearn movement patterns and skills.² Electromechanical delay (EMD) is defined as the time interval between the onset of electrical activity of the muscle and the mechanical response of the muscle.³ It corresponds to the time needed for the contractile component in the muscle-tendon complex to initiate stretching of the elastic component series,⁴ and its duration is related to the mechanical properties of the elastic component series (see Chapter 1).⁵ The shorter the EMD duration, the faster the muscle force transmission and the better the performance and protective reflex. Significantly longer EMDs in the ...