Although the integrated relationship that exists between the lumbar spine and hip joints is frequently acknowledged in scientific journals and by medical professionals, specific functional and injury relationships, are speculative and have not been substantiated. Lumbar spine and hip dysfunctions are suspected to be associated with inhibition of the surrounding extensor musculature, particularly the gluteal muscles, and facilitation of the flexor musculature. This phenomenon has been observed in other joints following effusion and is often termed ‘arthrogenic inhibition’. Its apparent occurrence about the hip has never been validated. The primary objective of this thesis was to investigate whether arthrogenic inhibition occurred about the hip. If inhibition was found to exist, its relationship with volume vs pressure was investigated to determine if either of these factors were a more appropriate predictor of inhibition. Finally, compensatory motor patterns in response to apparent inhibition were of interest. Participants were allocated to the following groups: 1) Control 2) Intervention I (magnetic resonance arthrogram) or 3) Intervention II (therapeutic arthrogram). Electromyography was collected on the rectus abdominis, erector spinae, gluteus maximus and semimenbranosis bilaterally during hip rehabilitation exercises prior to and following the intervention. Intra-capsular pressure was measured during the intervention. The findings provided support for the presence of extensor-inhibition in the hip following infusion of intra-articular fluid with intra-capsular pressure being the most appropriate predictor of the magnitude of inhibition. Hip extensor inhibition appeared to be compensated for by lumbar spine extensors during the selected tasks. Arthrogenic inhibition should be considered in the clinical evaluation and management of patients with hip joint effusions and/or elevated intra-capsular pressure.

Although the integrated relationship that exists between the lumbar spine and hip joints is frequently acknowledged in scientific journals and by medical professionals, specific functional and injury relationships, are speculative and have not been substantiated. Lumbar spine and hip dysfunctions are suspected to be associated with inhibition of the surrounding extensor musculature, particularly the gluteal muscles, and facilitation of the flexor musculature. This phenomenon has been observed in other joints following effusion and is often termed ‘arthrogenic inhibition’. Its apparent occurrence about the hip has never been validated. The primary objective of this thesis was to investigate whether arthrogenic inhibition occurred about the hip. If inhibition was found to exist, its relationship with volume vs pressure was investigated to determine if either of these factors were a more appropriate predictor of inhibition. Finally, compensatory motor patterns in response to apparent inhibition were of interest. Participants were allocated to the following groups: 1) Control 2) Intervention I (magnetic resonance arthrogram) or 3) Intervention II (therapeutic arthrogram). Electromyography was collected on the rectus abdominis, erector spinae, gluteus maximus and semimenbranosis bilaterally during hip rehabilitation exercises prior to and following the intervention. Intra-capsular pressure was measured during the intervention. The findings provided support for the presence of extensor-inhibition in the hip following infusion of intra-articular fluid with intra-capsular pressure being the most appropriate predictor of the magnitude of inhibition. Hip extensor inhibition appeared to be compensated for by lumbar spine extensors during the selected tasks. Arthrogenic inhibition should be considered in the clinical evaluation and management of patients with hip joint effusions and/or elevated intra-capsular pressure.

Sammanfattning Bakgrund: Patellofemoralt smärtsyndrom (PFSS) är ett vanligt förekommande muskuloskeletalt besvär bland kvinnor och karaktäriseras av smärta runt eller bakom patella, som förvärras vid vissa viktbärande aktiviteter. Då prevalens är hög hos kvinnor är det av stor betydelse att de får en välanpassad behandling baserad på den senaste tillgängliga evidensen. Syfte:  Att genom en litteraturstudie undersöka effekten av styrketräning på utfallsmåtten smärta och funktion hos kvinnor med PFSS samt gradera den aktuella evidensen. Metod: Litteratursökning utfördes i databasen PubMed. Nio artiklar inkluderades. Artiklarna granskades sedan enskilt enligt TESTEX scale och därefter bedömdes evidensgraden enligt SBU:s GRADE. Resultat: Studien visade en begränsad evidensgrad för att styrketräning av höftmuskulatur minskar smärta. Det finns även en begränsad evidensgrad för att kombinerad styrketräning av höft- och knämuskulatur minskar smärta och ökar funktion. Styrketräning av höftmuskulatur jämfört med styrketräning av endast knämuskulatur har ej effekt på funktion, men evidensgraden bedöms som begränsad. Studiekvaliteten av de enskilda studierna varierade mellan 7–13 poäng vid granskning med TESTEX scale. Konklusion: Evidensen talar för att kombinerad styrketräning av höft- och knämuskulatur bör användas i första hand vid behandling av PFSS, men fler studier behövs för att bekräfta studieresultatet.  Nyckelord: Exercise, hip musculature, patellofemoral pain syndrome, quadriceps musculature / Abstract Background: Patellofemoral pain syndrome (PFPS) is a common musculoskeletal condition among women and is characterized by pain around or behind the patella, which is aggravated by weightbearing activities. Since the prevalence among women is high, it is of great importance that they receive a well-adjusted treatment based on the latest available evidence. Objective: To investigate through a literature study the effect of strength training on the outcome measures pain and function among women with PFPS Method: The litterature search was conducted in the database PubMed. Nine papers were included. The papers were evaluated by each author using the TESTEX scale and then the level of evidence was assessed according to SBU’s GRADE. Results: There is limited evidence that strength training of the hip musculature reduces pain. There is also limited evidence that combined strength training of the hip and knee musculature reduces pain and increases function. Compared to strength training of the knee musculature, isolated strength training of the hip musculature is no better to increase function but the evidence is limited. The study quality of the included papers varied between 7–13 points after evaluation with TESTEX scale. Conclusion: The evidence suggests that combined strength training of the hip and knee musculature should be used as the first line of treatment when treating PFPS, but further research is warranted. Key words: Exercise, hip musculature, patellofemoral pain syndrome, quadriceps musculature