• Behavioral and cognitive-behavioral strategies became the dominant paradigm for managing chronic pain, integrating operant conditioning, attention modulation, and expectation/distraction techniques to alter pain perception across therapeutic contexts [1], [3], [15], [18], [17], [14].

• Biopsychosocial perspectives linked personality traits, psychophysiology, and pain expression, framing chronic pain as an interaction of psychological dispositions and bodily processes rather than a purely biomedical issue [4], [8], [13], [9], [7], [5].

• Diagnostic and syndrome-centric framing treated pain as a structured set of disorders with psychosocial implications, emphasizing myofascial/pain-dysfunction etiologies and atypical back-pain patterns [6], [16], [7], [13].

• Biomedical interventional approaches surfaced early, including neuromodulation and instrumentation, with dorsal column stimulation and strain-gauge pain stimulators illustrating device-based relief and selection challenges [10], [19].

• Psychophysical measurement and experimental paradigms advanced objective quantification of pain reporting versus sensation, shaping methods such as signal-detection theory, psychophysiological analyses, and experimentally induced distraction [14], [8], [5], [17], [20].